ARTICLE   Open Access    

Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits

More Information
  • The loss of valuable nutrient content of the whey proteins obtained from the dairy industry in general is disposed of causing sewage pollution. Therefore, this study aims to utilize the nutrient content of whey proteins to beverages using some Sudanese indigenous fruits: Baobab (Adansonia digitata L.), Roselle (Hibiscus sabdariffa L.) and Doum (Hyphaene thebaica) juices at a rate of 30:70, 50:50 and 70:30% for preparation of beverages. The processed beverages were evaluated for some chemicals, microbial, and sensory properties. Whey proteins enriched with Doum juice revealed significantly (p ≤ 0.05) high-fat level (0.93%), while that enriched with Roselle was significantly (p ≤ 0.05) higher in the protein value (5.97%). Whey proteins enriched with Baobab juice significantly (p ≤ 0.05) revealed a higher value for vitamin C (140.93 mg/100 mL). The values obtained for calcium and phosphorus were significantly (p ≤ 0.05) high in the whey enriched with Roselle juice (8.50 and 1.29 mg/100 mL, respectively). The heat treatment of whey proteins showed significant (p ≤ 0.05) reduction in the total viable bacterial counts. Moreover, the lactic acid bacteria were higher in plain whey proteins followed by those enriched Roselle and Baobab juices. Also, the whey proteins enriched with Roselle juice showed significantly (p ≤ 0.05) the best color. However, the whey proteins enriched with Doum juice significantly (p ≤ 0.05) revealed the best scores for flavor and taste. Hence, the present study concluded that it is possible to use some indigenous Sudanese fruits to utilize the whey proteins as functional food instead of its negative effect on the environment.
  • Salvia rosmarinus L. (old name Rosmarinus officinalis), common name Rosemary thrives well in dry regions, hills and low mountains, calcareous, shale, clay, and rocky substrates[1]. Salvia rosmarinus used since ancient times in traditional medicine is justified by its antiseptic, antimicrobial, anti-inflammatory, antioxidant, and antitumorigenic activity[1,2]. The main objective of the study is to evaluate the antimicrobial activity of different extracts of Salvia rosmarinus in vitro, and its compounds related to in silico targeting of enzymes involved in cervical cancer. Since the start of the 20th century, some studies have shown that microbial infections can cause cervical cancers worldwide, infections are linked to about 15% to 20% of cancers[3]. More recently, infections with certain viruses like Human papillomaviruses (HPV) and Human immunodeficiency virus (HIV), bacteria like Chlamydia trachomatis, and parasites like schistosomiasis have been recognized as risk factors for cancer in humans[3]. Then again, cancer cells are a group of diseases characterized by uncontrolled growth and spread of abnormal cells. Many things are known to increase the risk of cancer, including dietary factors, certain infections, lack of physical activity, obesity, and environmental pollutants[4]. Some studies have found that unbalanced common flora Lactobacillus bacteria around the reproductive organ of females increases the growth of yeast species (like Candida albicans) and some studies have found that women whose blood tests showed past or current Chlamydia trachomatis infection may be at greater risk of cervical cancer. It could therefore be that human papillomavirus (HPV) promotes cervical cancer growth[3]. Salvia rosmarinus is traditionally a healer chosen as a muscle relaxant and treatment for cutaneous allergy, tumors, increases digestion, and the ability to treat depressive behavior; mothers wash their bodies to remove bacterial and fungal infections, promote hair growth, and fight bad smells[5] .

    The study of plant-based chemicals, known as phytochemicals, in medicinal plants is gaining popularity due to their numerous pharmacological effects[6] against drug resistance pathogens and cancers. The causes of drug resistance to bacteria, fungi, and cancer are diverse, complex, and only partially understood. The factors may act together to initiate or promote infections and carcinogenesis in the human body is the leading cause of death[7]. Antimicrobial medicines are the cornerstone of modern medicine. The emergence and spread of drug-resistant pathogens like bacteria and fungi threaten our ability to treat common infections and to perform life-saving procedures including cancer chemotherapy and cesarean sections, hip replacements, organ transplantation, and other surgeries[7]. On the other hand, information about the current magnitude of the burden of bacterial and fungal drug resistance, trends in different parts of the world, and the leading pathogen–drug combinations contributing to the microbial burden is crucial. If left unchecked, the spread of drug resistance could make many microbial pathogens much more lethal in the future than they are today. In addition to these, cancers can affect almost any part of the body and have many anatomies and molecular subtypes that each require specific management strategies to avoid or inhibit them. There are more than 200 different types of cancer that have been detected. The world's most common cancers affecting men are lung, prostate, colorectal, stomach, and liver cancers[8]. While breast, cervix, colorectal, lung, and stomach cancers are the most commonly diagnosed among women[8]. Although some cancers said to be preventable they seem to still be one of the causes of death to humans, for example cervical cancer. The need to fill the gap to overcome the problem of searching for antimicrobials and anticancers from one source of Salvia rosmarinus is of importance.

    Cervical cancer is a common cancer in women and a prominent cause of death[9]. In Ethiopia, cervical cancer is a big deal for women aged 15 to 44, coming in as the second most common cancer[9]. Globally, it's the fourth most common prevalent disease for women[10]. Aberrant methylation of tumor-suppressor genes' promoters can shut down their important functions and play a big role in causing cervical tumors[10]. There are various cervical cancer repressor genes (proteins turn off or reduce gene expression from the affected gene), such as CCNA1, CHF, HIT, PAX1, PTEN, SFRP4, and TSC1. The genes play a crucial role in causing cervical cancer by regulating transcription and expression through promoter hypermethylation, leading to precursor lesions during cervical development and malignant transformation[11]. The process of DNA methylation is primarily carried out by a group of enzymes known as DNA methyltransferases (DNMT1). It has been reported that DNMT1 (PDB ID: 4WXX), a protein responsible for DNA methylation can contribute to the development of cervical cancer. DNMT1 inhibits the transcription of tumor suppressor genes, facilitating tumorigenesis, which finally develops into cervical cancer. Tumor suppressor gene transcription is inhibited by DNMT1, which helps cancer grow and eventually leads to cervical cancer. Repressive genes' hypermethylation may be decreased, their expression can be increased, and the phenotype of malignant tumors can be reversed by inhibiting the DNMT1 enzyme.

    On the other hand, infection by the human papilloma virus (HPV) phenotype 16, enzyme 6 (PDB ID: 4XR8) has been correlated with a greatly increased risk of cervical cancer worldwide[12]. Based on variations in the nucleotide sequences of the virus genome, over 100 distinct varieties of the human papilloma virus (HPV) have been identified (e.g. type 1, 2 etc.). Genital warts can result from certain types 6 and 11 of sexually transmitted HPVs. Other HPV strains, still, that can infect the genitalia, do not show any symptoms of infection[8]. Persistent infection with a subset of approximately 13 so-called 'high-risk' sexually transmitted HPVs, including such as types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68 different from the ones that cause warts may lead to the development of cervical intraepithelial neoplasia (CIN), vulvar intraepithelial neoplasia (VIN), penile intraepithelial neoplasia (PIN), and/or anal intraepithelial neoplasia (AIN). These are precancerous lesions and can progress to invasive cancer. Almost all occurrences of cervical cancer have HPV infection as a required component[13]. Superfluous infection by HPV type 16 E6 (PDB ID: 4XR8) has been correlated with a greatly increased genital risk of precursor cervical cancer worldwide[11]. Scholars more defined in major biochemical and biological activities of HPV type 16 E6 (PDB ID: 4XR8) in high-risk HPV oncogenes and how they may work together in the development of cervical disease and cancer[13].

    One potential approach to treat cervical cancer is to inhibit the activity of the DNMT1 and HPV type 16 E6 enzymes specifically[1316]. Over 50% of clinical drug forms worldwide originate from plant compounds[17]. In the past, developing new drugs was a lengthy and costly process. However, with the emergence of bioinformatics, the use of computer-based tools and methods have become increasingly important in drug discovery. One such method is molecular docking and ADMET profiling which involves using the structure of a drug to screen for potential candidates. This approach is known as structure-based drug design and can save both time and resources during the research process[15]. Structural-based drug designing addresses ligand binding sites with a known protein structure[15]. Using free binding energies, a computational method known as docking examines a large number of molecules and suggests structural theories for impeding the target molecule[17]. Nowadays, due to increasing antibiotic resistance like bacteria, fungi, and cancer cells, natural products remain an important source for discovering antimicrobial compounds and novel drugs for anti-cancers like cervical cancers. Therefore, the purpose of this research is to assess the antimicrobial activity of extracts, molecular docking, ADMET profiling in anticancer properties of compounds isolated from Salvia rosmarinus, on a targeting DNMT1 and HPV type 16 E6 in human cervical cancer. In the present study, various solvent crude extracts obtained from Salvia rosmarinus were used for antimicrobial activity and the isolated compounds 1 and 2 were submitted for in silico study to target the DNMT1 and HPV type 16 E6 enzymes to inhibit the growth of human cervical cancer cells.

    Healthy Salvia rosmarinus leaves were collected in Bacho district, Southwest Showa, Oromia, Ethiopia, during the dry season of November 2022. The plant materials were authenticated by Melaku Wondafrish, Natural Science Department, Addis Ababa University and deposited with a voucher number 3/2-2/MD003-80/8060/15 in Addis Ababa University's National Herbarium.

    The most common organic solvent used in extractions of medicinal plants is 2.5 L of petroleum ether, chloroform/methanol (1:1), and methanol. The test culture medium for microbes was used and performed in sterile Petri dishes (100 mm diameter) containing sterile Muller–Hinton Agar medium (25 mL, pH 7) and Sabouraud Dextrose Agar (SDA) for bacteria and fungi, respectively. A sterile Whatman filter paper (No. 1) disc of 6 mm diameter was used to determine which antibiotics an infective organism is sensitive to prescribed by a minimum zone of inhibition (MZI). Ciprofloxacin antibiotic reference (manufactured by Wellona Pharma Ciprofloxacin tablet made in India) and Ketoconazole 2% (made in Bangladesh) were used as a positive controls for antibacterial and antifungal, respectively and Dimethyl sulfoxide (DMSO) 98.9% was used as a negative control for antimicrobial tests. In the present study, the height of the column was 650 mm and the width was 80 mm. Several studies by previous researchers showed the acceptable efficiency of column chromatography (up to 43.0% w/w recovery) in the fractionation and separation of phenolic compounds from plant samples[18]. In column chromatography, the ideal stationary phase used silica gel 60 (0.200 mm) particles. The 1H-NMR spectrums of the compounds were analyzed using a 600 MHz NMR machine and 150 MHz for 13C NMR. The compounds were dissolved in MeOD for compound 1 and in DMSO for compound 2 for NMR analysis. On the other hand, UV spectroscopy (made in China) used 570 nm ultraviolet light to determine the absorbency of flavonoids (mg·g−1) phytochemicals.

    The samples (extracts) were analyzed to detect the presence of certain chemical compounds such as alkaloids (tested using Wagner's reagents), saponins (tested using the froth test), steroids (tested with Liebermann Burchard's tests), terpenoids (tested with Lidaebermann Burchard's tests), quinones, and flavonoids (tested using Shinoda tests)[19].

    The leaves of Salvia rosmarinus (500 g) were successively extracted using maceration using petroleum ether, chloroform/methanol (1:1), and methanol, every one 2.5 L for 72 h to afford 3.6, 6, and 53 g crude extracts, respectively. The methanol/chloroform (1:1) extract (6 g) was loaded to silica gel (150 g) column chromatography using the increasing polarity of petroleum ether, methanol/chloroform (1:1) solvent system to afford 80 fractions (100 mL each). The fraction obtained from chloroform/methanol 1:1 (3:2) after repeated column chromatography yielded compound 1 (18 mg). Fractions 56-65, eluted with chloroform/methanol (1:1) were combined and purified with column chromatography to give compound 2 (10 mg).

    The microorganisms were obtained from the Ethiopia Biodiversity Institution (EBI). Two gram-positive bacteria namely Staphylococcus aureus serotype (ATCC 25923) and Streptococcus epidermidis (ATCC14990); and three gram-negative bacteria, namely Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 5702), and Klebsiella pneumonia (ATCC e13883) were inoculated overnight at 37 °C in Muller–Hinton Agar/MHA culture medium and two fungus strains of Candida albicans (ATCC 16404) and Aspergillus niger (ATCC 11414) were inoculated overnight at 27−30 °C in Sabouraud Dextrose Agar/SDA culture medium[20].

    The antibacterial and antifungal activities of different crude extracts obtained from Salvia rosmarinus plant leaves were evaluated by the disk diffusion method (in accordance with the 13th edition of the CLSI M02 document on hardydiagnostics.com/disk-diffusion). Briefly, the test was performed in sterile Petri dishes (100 mm diameter) containing solid and sterile Muller–Hinton Agar medium (25 mL, pH 7) and Sabouraud Dextrose Agar (SDA) for bacteria and fungi, respectively. The extracts were placed on the surface of the media that had previously been injected with a sterile microbial suspension (one microbe per petri dish) after being adsorbed on sterile paper discs (5 μL per Whatman disc of 6 mm diameter). To prevent test samples from eventually evaporating, all Petri dishes were sealed with sterile laboratory films. They were then incubated at 37 °C for 24 h, and the zone diameter of the inhibition was measured and represented in millimeters. Ciprofloxacin antibiotic reference (manufactured by Wellona Pharma Ciprofloxacin tablet, India) was used as a positive control and DMSO was used as a negative control for antibacterial activity test while Ketoconazole 2% (Bangladesh) was used as a positive control and 10 μL of 0.2% agar as a negative control for antifungal activity tests[20]. The term 'inhibitory concentration' refers to the minimum sample concentration required to kill 99.9% of the microorganisms present[21]. Three repetitions of the crude extract sample were used to precisely measure the inhibitory halo diameter (in mm), which was then expressed as mean ± standard deviation to assess the anti-microbial activity.

    Cervical cancer-causing protein was identified through relevant literature. The protein molecule structure of DNA (cytosine-5)-methyltransferase 1 (DNMT1) (PDB ID: 4WXX)[21] and HPV type 16 E6 (PDB ID: 4XR8)[21] - a protein known to cause cervical cancer - were downloaded from the Protein Data Bank[22]. The stability of the protein molecule was assessed using Rampage[23].

    Phytochemical constituents of Salvia rosmarinus plant leaves were used to select a source of secondary metabolites (ligands). Ligand molecules were obtained through plant extraction, and isolation, and realized with PubChem (https://pubchem.ncbi.nlm.nih.gov/). The ligands were downloaded in Silver diamine fluoride format (SDF) and then converted to PDB format using an online SMILES translator (https://cactus.nci.nih.gov/translate/). The downloaded files were in PDB format, which was utilized for running various tools and software[24].

    The Biovia Discovery Studio Visualizer software was used to analyze the protein molecule. The protein molecule was converted into PDB format and its hierarchy was analyzed by selecting ligands and water molecules. Both the protein molecule and the water molecules lost their attached ligands during the analysis. Finally, the protein's crystal structure was saved in a PDB file[25].

    PyRx software was utilized to screen secondary metabolites and identify those ligands with the lowest binding energy to the protein target. The ligands with the lowest binding energy were further screened for their drug-likeliness property through analysis. It is worth noting that PyRx runs on PDBQT format. To begin using PyRx, it needs to load a protein molecule. This molecule should be converted from PDB to the protein data bank, partial charge (Q), and Atom Type (PDBQT) format. Once the protein molecule is loaded, it can import ligands from a specific folder in Silver diamine fluoride format. The ligand energy was minimized and changed to PDBQT format. The protein was docked with the ligand and screened based on minimum binding energy (https://cactus.nci.nih.gov/translate/).

    The optimal ligand was selected for final docking using AutoDock Vina and Biovia by modifying the reference of Discovery Studio Client 2021 (https://cactus.nci.nih.gov/translate/).

    The protein target from the Protein Data Bank (PDB) was loaded onto the graphical interface of AutoDock Vina. To prepare the protein for docking, water molecules were removed, hydrogen polar atoms were added, and Kollman charges were assigned to the protein molecule. Ultimately, PDBQT format was used to store the protein. After being imported in PDB format, the Ligand molecule was transformed to PDBQT format. Next, a grid box was chosen to represent the docked region. The command prompt was used to run AutoDock Vina and the outcomes were examined (https://cactus.nci.nih.gov/translate/).

    Docking the ligand with the protein target DNMT1(PDB ID: 4WXX)[22] and HPV type 16 E6 (PDB ID: 4XR8)[21] enzymes were performed using Biovia Discovery Studio Client 2021 by loading the protein target first followed by the ligand in PDB format. The charges were attached to the protein molecule, and the energy was minimized for the ligands. Both the protein and ligand molecules were prepared for docking. Once the docking process was complete, the results were analyzed based on several parameters, including absolute energy, clean energy, conf number, mol number, relative energy, and pose number. The interaction between the protein and ligand was analyzed using structure visualization tools, such as Biovia Discovery Studio Visualizer and PyMol (https://cactus.nci.nih.gov/translate/).

    The process of visualizing the structure was carried out using the PyMol tool. PyMol is a freely available software. Firstly, the protein molecule in PDBQT form was loaded on the PyMol graphical screen. Then, the output PDBQT file was added. The docked structure was visualized and the 'molecule' option was changed to 'molecular surface' under the 'shown as' menu (https://cactus.nci.nih.gov/translate/).

    Drug likeliness properties of the screened ligands were evaluated using the SwissADME online server. SMILE notations were obtained from PubChem and submitted to the SwissADME web server for analysis. The drugs were subjected to Lipinski's rule of five[20] for analysis. Lipinski's rules of five were selected for final docking through AutoDock Vina and Biovia Discovery Studio Client 2021. Ligands 1 and 2 were analyzed using Lipinski's rule of five for docking with AutoDock Vina and Biovia Discovery Studio Client 2021.

    The antimicrobial analysis data generated by triplicate measurements reported as mean ± standard deviation, and a bar graph also generated by GraphPad Prism version 8.0.1 (244) for Windows were used to perform the analysis. GraphPad Prism was used and combined with scientific graphing, comprehensive bar graph fitting (nonlinear regression), understandable statistics, and data organization. Prism allows the performance and modification of basic statistical tests commonly used and determined through the statistical applications in microbiology labs (https://graphpad-prism.software.informer.com/8.0/).

    Phytochemical screening of the different extracts for the presence (+) and absence (−) of alkaloids, steroids, glycosides, coumarins, terpenoids, flavonoids, carbohydrates, tannins, and saponins were done. The present study showed that alkaloids, terpenoids, flavonoids, and tannins tests in S. rosmarinus leaves of petroleum ether, chloroform/methanol (1:1), and methanol extracts were high whereas glycoside, coumarins, and carbohydrates had a moderate presence. The extract of S. rosmarinus leaves contain commonly bioactive constituents such as alkaloids, steroids, terpenoids, flavonoids, tannins, and saponins. These bioactive chemicals have active medicinal properties. Phytochemical compounds found in S. rosmarinus leaves have the potential to treat cancer cells and pathogens. The study also found that these flavonoids are related to natural phenolic compounds with anticancer and antimicrobial properties in the human diet (Table 1).

    Table 1.  Phytochemical screening tests result of petroleum ether, chloroform/methanol (1:1) and methanol extracts of Salvia rosmarinus leaves.
    Botanical name Phytochemicals Phytochemical screening tests Different extracts
    Petroleum ether Chloroform/methanol (1:1) Mehanol
    Salvia rosmarinus Alkaloids Wagner's test ++ ++ ++
    Steroids Libermann Burchard test ++ + ++
    Glycoside Keller-Killiani test +
    Coumarins Appirade test + +
    Terpenoids Libermann Burchard test ++ ++ ++
    Flavonoids Shinoda test ++ ++ ++
    Carbohydrate Fehling's test ++ ++
    Tannins Lead acetate test ++ ++ ++
    Saponins Foam test + + +
    + indicates moderate presence, ++ indicates highly present, − indicates absence.
     | Show Table
    DownLoad: CSV

    Two compounds were isolated and characterized using NMR spectroscopic methods (Fig. 1 & Supplementary Fig. S1ac). Compound 1 (10 mg) was isolated as yellow crystals from the methanol/chloroform (1:1) leaf extract of Salvia rosmarinus. The TLC profile showed a spot at Rf 0.42 with methanol/chloroform (3:2) as a mobile phase. The 1H-NMR spectrum (600 MHz, MeOD, Table 2, Supplementary Fig. S1a) of compound 1 showed the presence of one olefinic proton signal at δ 5.3 (t, J = 3.7 Hz, 1H), two deshielded protons at δ 4.7 (m, 1H), and 4.1 (m, 1H) associated with the C-30 exocyclic methylene group, and one O-bearing methine proton at δH 3.2 (m, 1H), and six methyl protons at δ 1.14 (s, 3H), 1.03 (d, J = 6.3 Hz, 3H), 1.00 (s, 3H), 0.98 (s, 3H), 0.87 (s, 3H), and 0.80 (s, 3H). A proton signal at δ 2.22 (d, J = 13.5 Hz, 1H) was attributed to methine proton for H-18. Other proton signals integrate for 20 protons were observed in the range δ 2.2 to 1.2. The proton decoupled 13C-NMR and DEPT-135 spectra (151 MHz, MeOD, Supplementary Fig. S1b & c) of compound 1 revealed the presence of 30 well-resolved carbon signals, suggesting a triterpene skeleton. The analysis of the 13C NMR spectrum displayed signals corresponding to six methyl, nine methylene, seven methine, and eight quaternary carbons. Among them, the signal observed at δ 125.5 (C-12) belongs to olefinic carbons. The methylene carbon showed signals at δC 39.9, 28.5, 18.1, 36.7, 23.9, 30.4, 26.5, 32.9, and 38.6. The quaternary carbons showed a signal at δC 39.4, 41.9, 38.4, 138.2, 41.8, and 47.8. The signals of exocyclic methylene carbon signals appeared at δ 153.1 and 103.9. The spectrum also showed sp3 oxygenated methine carbon at δ 78.3 and carboxyl carbon at δ 180.2. The spectrum revealed signals due to methyl groups at δC 27.4, 16.3, 15.0, 20.2, 22.7, and 16.4. The remaining carbon signals for aliphatic methines were shown at δC 55.3, 55.2, 53.0, and 37.1. The NMR spectral data of compound 1 is in good agreement with data reported for micromeric acid, previously reported from the same species by Abdel-Monem et al.[26]. (Fig. 1, Table 2).

    Figure 1.  Structure of isolated compounds from the leaves of Salvia rosmarinus.
    Table 2.  Comparison of the 13C-NMR spectral data of compound 1 and micromeric acid (MeOD, δ in ppm).
    Position NMR data of compound 1 Abdel-Monem
    et al.[26]
    1H-NMR 13C-NMR 13C-NMR
    1 38.60 39.9
    2 27.8 28.5
    3 3.2 (m, 1H) 78.3 80.3
    4 39.4 39.9
    5 55.3 56.7
    6 18.1 18.3
    7 36.7 34.2
    8 41.9 40.7
    9 53 48.8
    10 38.4 38.2
    11 23.9 24.6
    12 5.3 (t, J = 3.7 Hz, 1H) 125.5 127.7
    13 138.2 138
    14 41.8 43.3
    15 30.4 29.1
    16 26.5 25.6
    17 47.8 48
    18 δ 2.22 (d, J = 13.5 Hz, 1H) 55.2 56.1
    19 37.1 38.7
    20 153.1 152.8
    21 32.9 33.5
    22 39.0 40.1
    23 27.4 29.4
    24 16.3 16.9
    25 15.0 16.6
    26 20.2 18.3
    27 22.7 24.6
    28 180.2 177.8
    29 16.4 17.3
    30 4.7 (m, 1H), and 4.1 (m, 1H) 103.9 106.5
     | Show Table
    DownLoad: CSV

    Compound 2 (18 mg) was obtained as a white amorphous isolated from 40% methanol/chloroform (1:1) in petroleum ether fraction with an Rf value of 0.49. The 1H NMR (600 MHz, DMSO, Supplementary Fig. S2a) spectral-data showed two doublets at 7.79 (d, J = 8.7 Hz, 2H), and 6.90 (d, J = 8.7 Hz, 2H) which are evident for the presence of 1,4-disubstituted aromatic group. The oxygenated methylene and terminal methyl protons were shown at δ 4.25 (q, J = 7.1 Hz, 2H) and 1.29 (t, J = 7.1 Hz, 3H), respectively. The13C-NMR spectrum, with the aid of DEPT-135 (151 MHz, DMSO, Table 3, Supplementary Fig. S2b & c) spectra of compound 2 confirmed the presence of well-resolved seven carbon peaks corresponding to nine carbons including threee quaternary carbons, one oxygenated methylene carbon, one terminal methyl carbon, and two symmetrical aromatic methine carbons. The presence of quaternary carbon signals was shown at δ 120.9 (C-1), 148.2 (C-4), and ester carbonyl at δ 166.0 (C-7). The symmetry aromatic carbons signal was observed at δ 131.4 (C-2, 6), and 116.8 (C-3, 5). The oxygenated methylene and terminal methyl carbons appeared at δC 60.4 (C-8) and 14.7 (C-9), respectively. The spectral results provided above were in good agreement with those for benzocaine in the study by Alotaibi et al.[27]. Accordingly, compound 2 was elucidated to be benzocaine (4-Aminobenzoic acid-ethyl ester) (Table 3, Fig. 1, Supplementary Fig. S2ac), this compound has never been reported before from the leaves of Salvia rosmarinus.

    Table 3.  Comparison of the 1H-NMR, and 13C-NMR spectral data of compound 2 and benzocaine (DMSO, δ in ppm).
    Position NMR data of compound 2 Alotaibi et al.[27]
    1H-NMR 13C-NMR 1H-NMR 13C-NMR
    1 120.9 119
    2 7.79 (d, J = 8.7 Hz, 2H) 131.4 7.86 (d, J = 7.6 Hz) 132
    3 6.90 (d, J = 8.7 Hz, 2H) 116.8 6.83 (d, J = 7.6 Hz) 114
    4 148.2 151
    5 6.90 (d, J = 8.7 Hz, 2H) 116.8 6.83 (d, J = 7.6 Hz) 114
    6 7.79 (d, J = 8.7 Hz, 2H) 131.4 7.86 (d, J = 7.6 Hz) 132
    7 166.0 169
    8 4.3 (q, J = 7.1 Hz, 2H) 60.4 4.3 (q, J = 7.0 Hz) 61
    9 1.3 (t, J = 7.1 Hz, 3H) 14.7 1.36 (t, J = 7.0 Hz) 15
     | Show Table
    DownLoad: CSV

    The extracts and isolated compounds from Salvia rosmarinus were evaluated in vitro against microbes from gram-positive bacteria (S. aureus and S. epidermidis), gram-negative bacteria (E. coli, P. aeruginosa, and K. pneumoniae) and fungi (C. albicans and A. Niger) (Table 4). The petroleum ether extracts exhibited significant activity against all the present study-tested microbes at 100 μg·mL−1, resulting in an inhibition zone ranging from 7 to 21 mm. Chloroform/methanol (1:1) and methanol extracts demonstrated significant activity against all the present study-tested microbes at 100 μg·mL−1 exhibiting inhibition zones from 6 to 14 mm and 6 to 13 mm, respectively (Table 4). The chloroform/methanol (1:1) extracts were significantly active against bacteria of E. coli and K. pneumonia, and A. Niger fungi at 100 μg·mL−1. On the other hand, chloroform/methanol (1:1) extracts were significantly inactive against the S. rosmarinus and P. aeruginosa of bacteria and C. albicans of fungi, and again chloroform/methanol (1:1) extracts overall significantly active produced an inhibition zone of 12 to 14 mm (Table 4). Methanol extracts exhibited significant activity against S. aureus, E. coli bacteria, and A. Niger fungi at 100 μg·mL−1. The inhibition zone was recorded to be 11 to 13 mm. However, methanol extracts exhibited significant inactivity against K. pneumoniae (Table 4). The overall result of our studies shows that Salvia rosmarinus was extracted and evaluated in vitro, exhibiting significant antibacterial and antifungal activity, with inhibition zones recorded between 6 to 21 mm for bacteria and 5 to 21 mm for fungi. In our study, the positive control for ciprofloxacin exhibited antibacterial activity measured at 21.33 ± 1.15 mm, 15.00 ± 0.00 mm, and 14.20 ± 0.50 mm for petroleum ether, chloroform/methanol (1:1), and methanol extracts, respectively. Similarly, the positive control for ketoconazole demonstrated antifungal activity of 22.00 ± 1.00 mm, 13.67 ± 0.58 mm, and 15.00 ± 0.58 mm for petroleum ether, chloroform/methanol (1:1), and methanol extracts, respectively. Additionally, our findings indicated that the mean values of flavonoids (mg/g) tested were 92.2%, 90.4%, and 94.0% for petroleum ether, chloroform/methanol (1:1), and methanol extracts, respectively. This suggests that the groups of phenolic compounds evaluated play a significant role in antimicrobial activities, particularly against antibiotic-resistant strains.

    Table 4.  Comparison of mean zone of inhibition (MZI) leaf extracts of Salvia rosmarinus.
    Type of specimen, and standard antibiotics for
    each sample
    Concentration (μg·mL−1) of extract
    in 99.8% DMSO
    Average values of the zone of inhibition (mm)
    Gram-positive (+) bacteria Gram-negative (−) bacteria Fungai
    S. aurous S. epidermidis E. coli P. aeruginosa K. pneumoniae C. albicans A. niger
    Petroleum ether extracts
    S. rosmarinus 50 18.50 ± 0.50 15.33 ± 0.58 0.00 ± 0.00 0.00 ± 0.00 10.00 ± 0.00 15.93 ± 0.12 4.47 ± 0.50
    75 19.87 ± 0.06 17.00 ± 0.00 9.33 ± 0.29 10.53 ± 0.50 10.93 ± 0.12 18.87 ± 0.23 5.47 ± 0.50
    100 21.37 ± 0.78 17.50 ± 0.50 11.47 ± 0.50 13.17 ± 0.29 12.43 ± 0.51 20.83 ± 0.76 6.70 ± 0.10
    Standard antibiotics Cipro. 21.33 ± 1.15 18.33 ± 0.58 9.33 ± 0.58 12.30 ± 0.52 15.00 ± 0.00
    Ketocon. 22.00 ± 1.00 10.67 ± 0.58
    Chloroform/methanol (1:1) extracts
    50 5.47 ± 0.42 0.00 ± 0.00 10.33 ± 0.00 0.00 ± 0.00 9.70 ± 0.00 0.00 ± 0.12 8.47 ± 0.50
    S. rosmarinus
    75 5.93 ± 0.06 0.00 ± 0.00 11.33 ± 0.29 0.00 ± 0.50 12.50 ± 0.12 0.00 ± 0.23 10.67 ± 0.50
    100 6.47 ± 0.06 0.00 ± 0.00 14.17 ± 0.50 7.33 ± 0.29 14.17 ± 0.51 0.00 ± 0.76 12.67 ± 0.10
    Standard antibiotics Cipro. 15.00 ± 0.00 11.00 ± 1.00 11.33 ± 0.58 10.00 ± 0.52 12.67 ± 0.00
    Ketocon. 7.00 ± 1.00 13.67 ± 0.58
    Methanol extracts
    50 9.17 ± 0.29 5.50 ± 0.50 0.00 ± 0.00 7.50 ± 0.00 0.00 ± 0.00 6.57 ± 0.12 0.00 ± 0.50
    S. rosmarinus
    75 9.90 ± 0.10 6.93 ± 0.12 9.33 ± 0.29 8.50 ± 0.50 0.00 ± 0.00 8.70 ± 0.23 0.00 ± 0.50
    100 11.63 ± 0.55 7.97 ± 0.06 11.47 ± 0.50 9.90 ± 0.10 0.00 ± 0.00 10.83 ± 0.76 13.13 ± 0.10
    Standard antibiotics Cipro. 13.00 ± 0.00 11.50 ± 0.50 14.20 ± 0.58 13.33 ± 0.29 10.00 ± 0.00
    Ketocon. 12.00 ± 1.00 15.00 ± 0.58
    Mean values of flavonoids (mg·g−1) by 570 nm
    S. rosmarinus
    Petroleum ether extracts Chloroform/methanol (1:1) extracts Methanol extracts
    50 0.736 0.797 0.862
    75 0.902 0.881 0.890
    100 0.922 0.904 0.940
    Samples: Antibiotics: Cipro., Ciprofloxacin; Ketocon., ketoconazole (Nizoral); DMSO 99.8%, Dimethyl sulfoxide.
     | Show Table
    DownLoad: CSV

    Determining the three solvent extracts in S. rosmarinus plants resulted in relatively high comparable with positive (+) control. Especially, the S. rosmarinus petroleum ether leaf extracts against drug resistance human pathogenic bacteria S. aureus, S. epidermidis, E. coli, P. aeruginosa, and K. pneumoniae were minimum zone of inhibition (MZI) recorded that 21.37 ± 0.78, 17.50 ± 0.50, 11.47 ± 0.50, 13.17 ± 0.29, and 12.43 ± 0.51 mm, respectively and against human pathogenic fungi C. albicans and A. niger were minimum zone of inhibition (MZI) recorded that 20.83 ± 0.76 and 6.70 ± 0.10 mm, respectively which was used from bacteria against S. aureus MZI recorded that 21.37 ± 0.78 mm higher than the positive control (21.33 ± 1.15 mm). The S. rosmarinus of chloroform/methanol (1:1) extracts were found to be against E. coli (14.17 ± 0.50 mm) and K. pneumoniae (14.17 ± 0.51 mm) higher than the positive control 11.33 ± 0.58 and 12.67 ± 0.00 mm, respectively. The methanol extracts of leaves in the present study plants were found to have overall MZI recorded less than the positive control. The Salvia rosmarinus crude extracts showed better antifungal activities than the gram-negative (−) bacteria (Table 4, Fig 2, Supplementary Fig. S3). Therefore, the three extracts, using various solvents of different polarity indexes, have been attributed to specific biological activities. For example, the antimicrobial activities of Salvia rosmarinus extracts may be due to the presence of alkaloids, terpenoids, flavonoids, tannins, and saponins in natural products (Table 1).

    Figure 2.  Microbes' resistance with drugs relative to standard antibiotics in extracts of Salvia rosmarinus. The figures represent understudy of three extracts derived from Salvia rosmarinus. (a) Petroleum ether, (b) chloroform/methanol (1:1), and (c) methanol extracts tested in Salvia rosmarinus.

    Compounds 1 and 2 were isolated from chloroform/methanol (1:1) extract of Salvia rosmarinus (Fig. 1, Tables 2 & 3). The plant extract exhibited highest antibacterial results recorded a mean inhibition with diameters of 21 and 14 mm at a concentration of 100 mg·mL−1 against S. aureus and E. coli/K. pneumoniae, respectively. After testing, overall it was found that the highly active petroleum ether extract of Salvia rosmarinus was able to inhibit the growth of S. aureus and C. albicans, with inhibition zones of 21 and 20 mm, respectively. The petroleum ether extracts showed good efficacy against all tested microbes, particularly gram-positive bacteria and fungi (Table 4). This is noteworthy because gram-negative bacteria generally exhibit greater resistance to antimicrobial agents. Petroleum ether and chloroform/methanol (1:1) extracts of the leaves were used at a concentration of 100 mg·mL−1, resulting in impressive inhibition zone diameters of 11 and 14 mm for E. coli, 13 and 7 mm for P. aeruginosa, and 12 and 14 mm for K. pneumoniae, respectively.

    The present study found that at a concentration of 50 μg·mL−1, petroleum ether, chloroform/methanol (1:1), and MeOH extracts did not display any significant inhibition zone effects against the tested microbes. This implies that the samples have a dose-dependent inhibitory effect on the pathogens. The leaves of Salvia rosmarinus have been found to possess remarkable antimicrobial properties against gram-negative bacteria in different extracts such as E. coli, P. aeruginosa, and K. pneumoniae with 14.17 ± 0.50 in chloroform/methanol (1:1), 13.17 ± 0.29 in petroleum ether and 14.17 ± 0.51 in chloroform/methanol (1:1), respectively. However, in the present study, Salvia rosmarinus was found to possess remarkable high zones of inhibition with diameters of 21.37 ± 0.78 and 17.50 ± 0.50 mm antimicrobial properties against S. aureus, and S. epidermidis of gram-positive bacteria, respectively (Supplementary Fig. S3). The results are summarized in Fig. 2ac.

    The crystal structure of human DNMT1 (351-1600), classification transferase, resolution: 2.62 Å, PDB ID: 4WXX. Active site dimensions were set as grid size of center X = −12.800500 Å, center Y = 34.654981 Å, center Z = −24.870231 Å (XYZ axis) and radius 59.081291. A study was conducted to investigate the binding interaction of the isolated compounds 1 and 2 of the leaves of Salvia rosmarinus with the binding sites of the DNMT1 enzyme in human cervical cancer (PDB ID: 4WXX), using molecular docking analysis.

    The study also compared the results with those of standard anti-cancer agents Jaceosidin (Table 5 & Fig. 3). The compounds isolated had a final fixing energy extending from −5.3 to −8.4 kcal·mol−1, as shown in Table 4. It was compared to jaceosidin (–7.8 kcal·mol−1). The results of the molecular docking analysis showed that, compound 1 (−8.4 kcal·mol−1) showed the highest binding energy values compared with the standard drugs jaceosidin (–7.8 kcal·mol−1). Compound 2 has shown lower docking affinity (–5.3 kcal·mol−1) but good matching amino acid residue interactions compared to jaceosidin. After analyzing the results, it was found that the isolated compounds had similar residual interactions and docking scores with jaceosidin.

    Table 5.  Molecular docking results of ligand compounds 1 and 2 against DNMT1 enzyme (PDB ID: 4WXX).
    Ligands Binding affinity

    ( kcal·mol−1)
    H-bond Residual interactions
    Hydrophobic/electrostatic Van der Waals
    1 −8.4 ARG778 (2.85249), ARG778 (2.97417), VAL894 (2.42832) Lys-889, Pro-879, Tyr-865, His-795, Cys-893, Gly-760, Val-759, Phe-892, Phe-890, Pro-884, Lys-749
    2 −5.3 ARG596 (2.73996), ALA597 (1.84126), ILE422 (2.99493), THR424 (2.1965), ILE422 (2.93653) Electrostatic Pi-Cation-ARG595 (3.56619), Hydrophobic Alkyl-ARG595 (4.15839), Hydrophobic Pi-Alkyl-ARG595 (5.14967) Asp-423, Glu-428, Gly-425, Ile-427, Trp-464, Phe-556, Gln-560, Gln-594, Glu-559, Gln-598, Ser-563
    Jaceosidin −7.8 ASP571 (2.93566), GLN573 (2.02126), GLU562 (2.42376), GLN573 (3.49555), GLU562 (3.46629) Hydrophobic Alkyl-PRO574 (4.59409), Hydrophobic Alkyl-ARG690 (5.09748), Hydrophobic Pi-Alkyl-PHE576 (5.1314), Hydrophobic Pi-Alkyl-PRO574 (4.97072), Hydrophobic Pi-Alkyl-ARG690 (5.07356) Glu-698, Cys-691, Ala-695, Pro-692, Val-658, Glu-566, Asp-565
     | Show Table
    DownLoad: CSV
    Figure 3.  The 2D and 3D binding interactions of compounds against DNMT1 enzyme (PDB ID: 4WXX). The 2D and 3D binding interactions of compound 1 and 2 represent against DNMT1 enzyme, and jaceosidin (standard) against DNMT1 enzyme.

    Hence, compound 1 might have potential anti-cancer agents. However, anti-cancer in vitro analysis has not yet been performed. Promising in silico results indicate that further research could be beneficial. The 2D and 3D binding interactions of compounds 1 and 2 against human cervical cancer of DNMT1 enzyme (PDB ID: 4WXX) are presented in Fig. 3. The binding interactions between the DNMT1 enzyme (PDB ID: 4WXX), and compound 1 (Fig. 3) and compound 2 (Fig. 3) were displayed in 3D. Compounds and amino acids are connected by hydrogen bonds (green dash lines) and hydrophobic interactions (non-green lines).

    Crystal structure of the HPV16 E6/E6AP/p53 ternary complex at 2.25 Å resolution, classification viral protein, PDB ID: 4XR8. Active site dimensions were set as grid size of center X = −43.202782 Å, center Y = −39.085513 Å, center Z = −29.194115 Å (XYZ axis), R-value observed 0.196, and Radius 65.584122. A study was conducted to investigate the binding interaction of the isolated compounds 1 and 2 of the leaves of Salvia rosmarinus with the binding sites of the enzyme of human papilloma virus (HPV) type 16 E6 (PDB ID: 4XR8), using molecular docking analysis software. The study also compared the results with those of standard anti-cancer agents jaceosidin (Table 6 & Fig. 4). The compounds isolated had a bottom most fixing energy extending from −6.3 to −10.1 kcal·mol−1, as shown in Table 6. It was compared to jaceosidin (–8.8 kcal·mol−1). The results of the molecular docking analysis showed that, compound 1 (−10.1 kcal·mol−1) showed the highest binding energy values compared with the standard drugs jaceosidin (–8.8 kcal·mol−1). Compound 2 has shown lower docking affinity (–6.3 kcal·mol−1) but good matching amino acid residue interactions compared to jaceosidin. After analyzing the results, it was found that the isolated compounds had similar residual interactions and docking scores with jaceosidin.

    Table 6.  Molecular docking results of ligand compounds 1 and 2 against HPV type 16 E6 (PDB ID: 4XR8).
    Ligands Binding affinity
    (kcal·mol−1)
    H-bond Residual interactions
    Hydrophobic/electrostatic Van der Waals
    1 −10.1 ASN101 (2.25622), ASP228 (2.88341) Asp-148, Lys-176, Lys-180, Asp-178, Ile-179, Tyr-177, Ile-334, Glu-382, Gln-336, Pro-335, Gln-73, Arg-383, Tyr-100
    2 −6.5 TRP63 (1.90011), ARG67 (2.16075), ARG67 (2.8181) Hydrophobic Pi-Sigma-TRP341 (3.76182), Hydrophobic Pi-Pi Stacked-TYR156 (4.36581), Hydrophobic Pi-Pi T-shaped-TRP63 (5.16561), Hydrophobic Pi-Pi T-shaped-TRP63 (5.44632), Hydrophobic Alkyl-PRO155 (4.34691), Hydrophobic Pi-Alkyl-TRP341 (4.11391), Hydrophobic Pi-Alkyl-ALA64 (4.61525) Glu-154, Arg-345, Asp-66, Met-331, Glu-112, Lys-16, Trp-231
    Jaceosidin −8.8 ARG146 (2.06941), GLY70 (3.49991), GLN73 (3.38801) Electrostatic Pi-Cation-ARG67 (3.93442), Hydrophobic Pi-Alkyl-PRO49 (5.40012) Tyr-342, Tyr-79, Ser-338, Arg-129, Pro-335, Leu-76, Tyr-81, Ser-74, Tyr-71, Ser-80, Glu-46
     | Show Table
    DownLoad: CSV
    Figure 4.  The 2D and 3D binding interactions of compounds against HPV type 16 E6 (PDB ID: 4XR8). The 2D and 3D binding interactions of compound 1 and 2 represent against HPV type 16 E6 enzyme, and jaceosidin (standard) against HPV type 16 E6 enzyme.

    Hence, compounds 1 and 2 might have potential anti-cancer agents of HPV as good inhibitors. However, anti-cancer in vitro analysis has not been performed yet on HPV that causes cervical cancer agents. Promising in silico results indicate that further research could be beneficial. The 2D and 3D binding interactions of compounds 1 and 2 against human papilloma virus (HPV) type 16 E6 enzyme (PDB ID: 4XR8) are presented in Fig. 4. The binding interactions between the HPV type 16 E6 enzyme (PDB ID: 4XR8) and compound 1 (Fig. 4) and compound 2 (Fig. 4) were displayed in 3D. Compounds and amino acids are connected by hydrogen bonds (magenta lines) and hydrophobic interactions (non-green lines).

    In silico bioactivities of a drug, including drug-likeness and toxicity, predict its oral activity based on the document of Lipinski's Rule[25] was stated and the results of the current study showed that the compounds displayed conform to Lipinski's rule of five (Table 7). Therefore, both compounds 1 and 2 should undergo further investigation as potential anti-cancer agents. Table 8 shows the acute toxicity predictions, such as LD50 values and toxicity class classification (ranging from 1 for toxic, to 6 for non-toxic), for each ligand, revealing that none of them were acutely toxic. Furthermore, they were found to be similar to standard drugs. Isolated compound 1 has shown toxicity class classification 4 (harmful if swallowed), while 2 showed even better toxicity prediction giving results of endpoints such as hepatotoxicity, mutagenicity, cytotoxicity, and irritant (Table 8). All the isolated compounds were predicted to be non-hepatotoxic, non-irritant, and non-cytotoxic. However, compound 1 has shown carcinogenicity and immunotoxicity (Table 9). Hence, based on ADMET prediction analysis, none of the compounds have shown acute toxicity, so they might be proven as good drug candidates.

    Table 7.  Drug-likeness predictions of compounds computed by Swiss ADME.
    Ligands Formula Mol. Wt. (g·mol−1) NRB NHA NHD TPSA (A°2) Log P (iLOGP) Log S (ESOL) Lipinski's rule of five
    1 C30H46O3 454.68 1 3 2 57.53 3.56 −6.21 1
    2 C 9H11NO2 165.19 3 2 1 52.32 1.89 −2.21 0
    Jaceosidin C17H14O7 330.3 3 7 3 105 1.7 1 0
    NHD, number of hydrogen donors; NHA, number of hydrogen acceptors; NRB, number of rotatable bonds; TPSA, total polar surface area; and log P, octanol-water partition coefficients; Log S, turbid metric of solubility.
     | Show Table
    DownLoad: CSV
    Table 8.  Pre ADMET predictions of compounds, computed by Swiss ADME.
    Ligands Formula Skin permeation value
    (logKp - cm·s−1)
    GI
    absorption
    Inhibitor interaction
    BBB permeability Pgp substrate CYP1A2 inhibitor CYP2C19 inhibitor CYP2C9 inhibitor CYP2D6 inhibitor
    1 C30H46O3 −4.44 Low No No No No No No
    2 C 9H11NO2 −5.99 High Yes No No No No No
    Jaceosidin C17H14O7 −6.13 High No No Yes No Yes Yes
    GI, gastrointestinal; BBB, blood brain barrier; Pgp, P-glycoprotein; and CYP, cytochrome-P.
     | Show Table
    DownLoad: CSV
    Table 9.  Toxicity prediction of compounds, computed by ProTox-II and OSIRIS property explorer.
    Ligands Formula LD50
    (mg·kg−1)
    Toxicity
    class
    Organ toxicity
    Hepatotoxicity Carcinogenicity Immunotoxicity Mutagenicity Cytotoxicity Irritant
    1 C30H46O3 2,000 4 Inactive Active Active Inactive Inactive Inactive
    2 C 9H11NO2 NA NA Inactive Inactive Inactive Inactive Inactive Inactive
    Jaceosidin C17H14O7 69 3 Inactive Inactive Inactive Inactive Inactive Inactive
    NA, not available.
     | Show Table
    DownLoad: CSV

    Rosemary is an evergreen perennial plant that belongs to the family Lamiaceae, previously known as Rosmarinus officinalis. Recently, the genus Rosmarinus was combined with the genus Salvia in a phylogenetic study and became known as Salvia rosmarinus[28,29] and it has been used since ancient times for various medicinal, culinary, and ornamental purposes. In the field of food science, rosemary is well known as its essential oil is used as a food preservative, thanks to its antimicrobial and antioxidant properties, rosemary has many other food applications such as cooking, medicinal, and pharmacology uses[30]. According to the study, certain phytochemical compounds found in Salvia rosmarinus leaves have the potential to halt the growth of cancer cells, and pathogens or even kill them[31]. In literature, alkaloids are found mostly in fungi and are known for their strong antimicrobial properties, which make them valuable in traditional medicine[32,33]. However, in the present study, S. rosmarinus species have been shown to possess alkaloids. Most alkaloids have a bitter taste and are used to protect against antimalarial, antiasthma, anticancer, antiarrhythmic, analgesic, and antibacterial[33] also some alkaloids containing nitrogen such as vincristine, are used to treat cancer.

    Steroids occur naturally in the human body. They are hormones that help regulate our body's reaction to infection or injury, the speed of metabolism, and more. On the other hand, steroids are reported to have various biological activities such as chronic obstructive pulmonary disease (COPD), multiple sclerosis, and imitate male sex hormones[34]. It is a natural steroid compound occurring both in plants and animals[35]. Thus, were found in the present study. Terpenoids are derived from mevalonic acid (MVA) which is composed of a plurality of isoprene (C5) structural units. Terpenoids, like mono-terpenes and sesquiterpenes, are widely found in nature and more than 50,000 have been found in plants that reduce tumors and cancers. Many volatile terpenoids, such as menthol and perillyl alcohol, are used as raw materials for spices, flavorings, and cosmetics[36]. In the present study, high levels of these compounds were found in Salvia rosmarinus leaves.

    Flavonoids are a class of phenolic compounds commonly found in fruits and vegetables and are considered excellent antioxidants[37]. Similarly, the results of this study revealed that S. rosmarinus contain flavonoids. According to the literature, these flavonoids, terpenoids, and steroid activities include anti-diabetic, anti-inflammatory, anti-cancer, anti-bacterial, hepatic-protective, and antioxidant effects[36]. Tannins are commonly found in most terrestrial plants[38] and have the potential to treat cancer, and HIV/AIDS as well as to treat inflamed or ulcerated tissues. Similarly, in the present study, tannins were highly found in the presented plant. On the other hand, due to a sudden rise in the number of contagious diseases and the development of antimicrobial resistance against current drugs, drug development studies are vital to discovering novel medicinal compounds[30] and add to these cancer is a complex multi-gene disease[39] as in various cervical cancer repressor genes[11] that by proteins turn off or reduce gene expression from the affected gene to cause cervical cancer by regulating transcription and expression through promoter hypermethylation (DNMT1), leading to precursor lesions during cervical development and malignant transformation.

    In a previous study[40], a good antibacterial result was recorded at a median concentration (65 μg·mL−1). Methanol extract showed a maximum and minimum zone antibacterial result against negative bacteria E. coli 14 + 0.71 and most of the petroleum ether tests show null zone of inhibition. However, in the present study at a concentration of 100 μg·mL−1, the methanol extract demonstrated both maximum and minimum antibacterial zones against E. coli 11.47 ± 0.50. Conversely, the test conducted with petroleum ether exhibited a good zone of inhibition by increasing concentration. Further research may be necessary to determine the optimal concentration for this extract to maximize its efficacy. The results obtained in gram-negative bacteria such as E. coli, P. aeruginosa, and K. pneumoniae are consistent with previous research findings[41]. However, in the present study, Salvia rosmarinus has been found to possess high zones of inhibition with diameters of 21.37 ± 0.78 and 17.50 ± 0.50 mm antimicrobial properties against S. aureus, and S.epidermidis of gram-positive bacteria, respectively (Table 4 & Fig. 2, Supplementary Fig. S3). According to a previous study[42], the ethanolic leaf extract of Salvia rosmarinus did exhibit activity against C. albicans strains. In the present study, the antifungal activity of petroleum ether extracts from Salvia rosmarinus were evaluated against two human pathogenic fungi, namely C. albicans and A. niger. The findings showed that at a concentration of 100 μg·mL−1, the extracts were able to inhibit the growth of C. albicans 20.83 ± 0.76 resulting in a minimum zone of inhibition.

    Antimicrobial agents can be divided into groups based on the mechanism of antimicrobial activity. The main groups are: agents that inhibit cell wall synthesis, depolarize the cell membrane, inhibit protein synthesis, inhibit nucleic acid synthesis, and inhibit metabolic pathways in bacteria. On the other hand, antimicrobial resistance mechanisms fall into four main categories: limiting the uptake of a drug; modifying a drug target; inactivating a drug; and active drug efflux. Because of differences in structure, etc., there is a variation in the types of mechanisms used by gram-negative bacteria vs gram-positive bacteria. Gram-negative bacteria make use of all four main mechanisms, whereas gram-positive bacteria less commonly use limiting the uptake of a drug[43]. The present findings showed similar activity in chloroform/methanol (1:1) and methanol extracts of leaves of Salvia rosmarinus than gram-negative bacteria like P. aeruginosa and Klebsiella pneumoniae. However, Staphylococcus epidermidis of gram-positive bacteria under chloroform/methanol (1:1) extracts have similarly shown antimicrobial résistance. This occurred due to intrinsic resistance that may make use of limiting uptake, drug inactivation, and drug efflux that need further study. The structure of the cell wall thickness and thinners of gram-negative and gram-positive bacteria cells, respectively when exposed to an antimicrobial agent, there happen two main scenarios may occur regarding resistance and persistence. In the first scenario, resistant cells survive after non-resistant ones are killed. When these resistant cells regrow, the culture consists entirely of resistant bacteria. In the second scenario, dormant persistent cells survive. While the non-persistent cells are killed, the persistent cells remain. When regrown, any active cells from this group will still be susceptible to the antimicrobial agent.

    Ferreira et al.[44] explained that with molecular docking, the interaction energy of small molecular weight compounds with macromolecules such as target protein (enzymes), and hydrophobic interactions and hydrogen bonds at the atomic level can be calculated as energy. Several studies have been conducted showing natural products such as epigallocatechin-3-gallate-3-gallate (EGCG), curcumin, and genistein can be used as an inhibitor of DNMT1[4547] . In the literature micromenic (1) is used for antimicrobial activities and for antibiotic-resistance like methicillin-resistant Staphylococcus aureus (MRSA)[48], and benzocaine (2) is used to relieve pain and itching caused by conditions such as sunburn or other minor burns, insect bites or stings, poison ivy, poison oak, poison sumac, minor cuts, or scratches[49]. However, in the present study, Salvia rosmarinus was used as a source of secondary metabolites (ligands) by using chloroform/methanol (1:1) extract of the plant leaves yielded to isolate micromeric (1) and benzocaine (2) in design structure as a candidate for drugs as inhibitors of the DNMT1 enzyme by inhibiting the activity of DNMT1 that prevent the formation of cervical cancer cells.

    Cervical cancer is one of the most dangerous and deadly cancers in women caused by Human papillomaviruses (HPV). Some sexually transmitted HPVs (type 6 owner of E6) may cause genital warts. There are several options for the treatment of early-stage cervical cancer such as surgery, nonspecific chemotherapy, radiation therapy, laser therapy, hormonal therapy, targeted therapy, and immunotherapy, but there is no effective cure for an ongoing HPV infection. In the present study, Salvia rosmarinus leaves extracted and isolated compounds 1 and 2 are one of the therapeutic drugs design structure as a candidate drug for inhibiting HPV type 16 E6 enzyme. Similarly, numerous researchers have conducted studies on the impact of plant metabolites on the treatment of cervical cancer. Their research has demonstrated that several compounds such as jaceosidin, resveratrol, berberin, gingerol, and silymarin may be active in treating the growth of cells[47].

    Small-molecule drugs are still most commonly used in the treatment of cancer[50]. Molecular docking in in silico looks for novel small-molecule (ligands) interacting with genes or DNA or protein structure agents which are still in demand, newly designed compounds are required to have a specific even multi-targeted mechanism of action to anticancer and good selectivity over normal cells. In addition to these, in the literature, anti-cancer drugs are not easily classified into different groups[51]. Thus, drugs have been grouped according to their chemical structure, presumed mechanism of action, and cytotoxic activity related to cell cycle arrest, transcription regulation, modulating autophagy, inhibition of signaling pathways, suppression of metabolic enzymes, and membrane disruption[52]. Another problem for grouping anticancers often encountered is the resistance that may emerge after a brief period of a positive reaction to the therapy or may even occur in drug-naïve patients[50]. In recent years, many studies have investigated the molecular mechanism of compounds affecting cancer cells and results suggest that compounds exert their anticancer effects by providing free electron charge inhibiting some of the signaling pathways that are effective in the progression of cancer cells[53] and numerous studies have shown that plant-based compounds such as phenolic acids and sesquiterpene act as anticancer agents by affecting a wide range of molecular mechanisms related to cancer[53]. The present investigations may similarly support molecular mechanisms provided for the suppression of metabolic enzymes of cervical cancer.

    The main aim of the study was to evaluate the antimicrobial activity of different extracts of Salvia rosmarinus in vitro, and its compounds related to in silico targeting of enzymes involved in cervical cancer. The phytochemical screening tests indicated the presence of phytochemicals such as alkaloids, terpenoids, flavonoids, and tannins in its extracts. The plant also exhibited high antimicrobial activity, with varying efficacy in inhibiting pathogens in a dose-dependent manner (50−100 μg·mL−1). However, this extract exhibited a comparatively high inhibition zone in gram-positive and gram-negative bacteria had lower inhibition zones against E. coli, P. aeruginosa, and K. pneumoniae, respectively, and stronger antifungal activity 20.83 ± 0.76 mm inhibition zone against C. albicans fungi. Molecular docking is a promising approach to developing effective drugs through a structure-based drug design process. Based on the docking results, the in silico study predicts the best interaction between the ligand molecule and the protein target DNMT1 and HPV type 16 E6. Compound 1 (–8.3 kcal·mol−1) and 2 (–5.3 kcal·mol−1) interacted with DNMT1 (PDB ID: 4WXX) and the same compound 1 (–10.1 kcal·mol−1) and 2 (–6.5 kcal·mol−1) interacted with HPV type 16 E6 (PDB ID: 4XR8). Compounds 1 and 2 may have potential as a medicine for treating agents of cancer by inhibiting enzymes DNMT1 and HPV type 16 E6 sites, as well as for antimicrobial activities. None of the compounds exhibited acute toxicity in ADMET prediction analysis, indicating their potential as drug candidates. Further studies are required using the in silico approach to generate a potential drug through a structure-based drug-designing approach.

  • The authors confirm contribution to the paper as follows: all authors designed and comprehended the research work; plant materials collection, experiments performing, data evaluation and manuscript draft: Dejene M; research supervision and manuscript revision: Dekebo A, Jemal K; NMR results generation: Tufa LT; NMR data analysis: Dekebo A, Tegegn G; molecular docking analysis: Aliye M. All authors reviewed the results and approved the final version of the manuscript.

  • All data generated or analyzed during this study are included in this published article.

  • This work was partially supported by Adama Science and Technology University under Grant (ASTU/SP-R/171/2022). We are grateful for the fellowship support from Adama Science and Technology University (ASTU), the identification of plants by Mr. Melaku Wendafrash, and pathogenic strain support from the Ethiopian Biodiversity Institute (EBI). We also thank the technical assistants of the Applied Biology and Chemistry departments of Haramaya University (HU) for their help.

  • The authors declare that they have no conflict of interest.

  • [1]

    Boye J, Wijesinha-Bettoni R, Burlingame B. 2012. Protein quality evaluation twenty years after the introduction of the protein digestibility corrected amino acid score method. British Journal of Nutrition 108:S183−S211

    doi: 10.1017/S0007114512002309

    CrossRef   Google Scholar

    [2]

    Naik YK, Khan A, Choundhary PL, Goel BK, Shrivastava A. 2009. Studies on physic-chemical and sensory characteristics of whey based watermelon beverage. Asian Journal of Research in Chemistry 2:57−59

    Google Scholar

    [3]

    Dhanraj P, Jana A, Modha H, Aparnathi KD. 2017. Influence of using a blend of rennet casein and whey protein concentrate as protein source on the quality of Mozzarella cheese analogue. Journal of Food Science and Technology 54(3):822−31

    doi: 10.1007/s13197-017-2528-5

    CrossRef   Google Scholar

    [4]

    Mills S, Ross RP, Hill C, Fitzgerald GF, Stanton C. 2011. Milk intelligence: Mining milk for bioactive substances associated with human health. International Dairy Journal 21(6):377−401

    doi: 10.1016/j.idairyj.2010.12.011

    CrossRef   Google Scholar

    [5]

    Cruz AG, Sant'Ana AdS, Macchione MM, Teixeira ÂM, Schmidt FL. 2009. Milk drink using whey butter cheese (queijo manteiga) and acerola juice as a potential source of vitamin C. Food and Bioprocess Technology 2(4):368−73

    doi: 10.1007/s11947-008-0059-9

    CrossRef   Google Scholar

    [6]

    Sakhale BK, Pawar VN, Ranveer RC. 2012. Studies on the development and storage of whey based RTS beverage from Mango cv. Kesar. Journal of Food Processing & Technology 3(3):148

    doi: 10.4172/2157-7110.1000148

    CrossRef   Google Scholar

    [7]

    Argenta AB, De Lima JJ, Nogueira A, Scheer ADP. 2021. Evaluation of concentration process of bovine goat and buffalo whey proteins by ultrafiltration. Journal of Food Science and Technology 58:1663−72

    doi: 10.1007/s13197-020-04675-0

    CrossRef   Google Scholar

    [8]

    Deshwal GK, Akshit, Kadyan S, Sharma H, Singh AK, et al. 2021. Applications of reverse osmosis in dairy processing: An Indian perspective. Journal of Food Science and Technology 58:3676−88

    doi: 10.1007/s13197-020-04958-6

    CrossRef   Google Scholar

    [9]

    Sikder B, Sarkar K, Ray PR, Ghatak PK. 2001. Studies on shelf-life of whey-based mango beverages. Beverage Food World 28:53−54

    Google Scholar

    [10]

    Abdalla AA, Yagoup NEH, Mudawi HA. 2010. Production and quality evaluation of Baobab (Adansonia digitata) beverages. Journal of Applied Sciences Research 6(6):729−41

    Google Scholar

    [11]

    Chadare FJ, Linnemann AR, Hounhouigan JD, Nout MJR, Van Boekel MAJS. 2008. Baobab food products: a review on their composition and nutritional value. Critical Reviews in Food Science and Nutrition 49(3):254−74

    doi: 10.1080/10408390701856330

    CrossRef   Google Scholar

    [12]

    Ali H, El Zubeir I. 2020. Microbiological and sensory evaluation of camel milk ice cream using Vanilla Baobab (Adanisonia digitata) and papaya (Carica papaya) and papaya (Carica papaya) fruits. Annals Food Science and Technology 21(2):326−37

    Google Scholar

    [13]

    Ali H, El Zubeir I. 2023. Effects of some fruits on the processing and composition of camel milk ice cream. Croatian Journal of Food Science and Technology 15(1):56−62

    doi: 10.17508/CJFST.2023.15.1.07

    CrossRef   Google Scholar

    [14]

    Higginbotham KL, Burris KP, Zivanovic S, Davidson PM, Stewart CN Jr. 2014. Antimicrobial activity of Hibiscus sabdariffa aqueous extracts against Escherichia coli O157: H7 and Staphylococcus aureus in a microbiological medium and milk of various fat concentrations. Journal of Food Protection 77(2):262−68

    doi: 10.4315/0362-028X.JFP-13-313

    CrossRef   Google Scholar

    [15]

    El Naim AM, Ahmed SE 2010. Effect of weeding frequencies on growth and yield of two Roselle (Hibiscus sabdariffa L.) varieties under rain fed. Australian Journal of Basic and Applied Sciences 4(9):4250–55 www.researchgate.net/profile/Ahmed-El-Naim/publication/233945985_Effect_of_Weeding_Frequencies_on_Growth_and_Yield_of_Two_Roselle_Hibiscus_sabdariffa_L_Varieties_under_Rain_Fed/links/0912f50d36933b7c45000000/Effect-of-Weeding-Frequencies-on-Growth-and-Yield-of-Two-Roselle-Hibiscus-sabdariffa-L-Varieties-under-Rain-Fed.pdf

    [16]

    Khalid H, Abdalla WE, Abdelgadir H, Opatzand T, Efferth T. 2012. Gems from traditional north-African medicine: Medicinal and aromatic plants from Sudan. Natural Products and Bioprospecting 2(3):92−103

    doi: 10.1007/s13659-012-0015-2

    CrossRef   Google Scholar

    [17]

    Cid-Ortega S, Guerrero-Beltrán JA. 2015. Roselle calyces (Hibiscus sabdariffa) an alternative to the food and beverages industries: A review. Journal of Food Science and Technology 52(11):6859−69

    doi: 10.1007/s13197-015-1800-9

    CrossRef   Google Scholar

    [18]

    Hsu B, Coupar IM, Ng K. 2006. Antioxidant activity of hot water extract from the fruit of the Doum palm Hyphaene thebaica. Food Chemistry 98:317−28

    doi: 10.1016/j.foodchem.2005.05.077

    CrossRef   Google Scholar

    [19]

    Lokuruka MNI. 2008. Fatty acids in the nut of the Turkana Doam palm (Hyphaene coriacea). African Journal of Food, Agriculture, Nutrition and Development 8:118−32

    doi: 10.4314/ajfand.v8i2.19184

    CrossRef   Google Scholar

    [20]

    Aamer R. 2015. Physicohemical properties of Doum (Hyphaene thebaica) fruits and utilization of its flour in formulating some functional foods. Alexandria Journal of Food Science and Technology 12(2):29−40

    doi: 10.12816/0025396

    CrossRef   Google Scholar

    [21]

    Association of Official Analytical Chemist (AOAC). 2003. Official methods of analysis. 17th Edition. Washington, D.C., USA: AOAC.

    [22]

    Richards EL. 1959. The reaction of lactose with anthrone and its application to the estimation of lactose in casein and other dairy products. Journal of Dairy Research 26(1):53−57

    doi: 10.1017/S0022029900009663

    CrossRef   Google Scholar

    [23]

    Lowry OH, Lopez JA, Bessey OA. 1945. The determination of ascorbic acid in small amounts of blood serum. Journal of Biochemistry 160:609−15

    Google Scholar

    [24]

    Chapman HD, Pratt PE. 1961. Methods of analysis for soils, plants and water. Los Angeles, USA: University of California.

    [25]

    Barrow GI, Feltham RKA. 1993. Cowan and Steel's Manual for the identification of medical bacteria. 3rd Edition. UK: Cambridge University Press.

    [26]

    Houghtby GA, Maturin LG, Koeng EK. 1992. Microbiological count methods. In Standard methods for the examination of dairy products, ed. Marshall RT. 16th Edition. Washington, D.C.: American Public Health Association. https://doi.org/10.2105/9780875533438ch09

    [27]

    Kiss I. 1984. Effect of Vanilla, Baobab (Adanisonia digitata) Papaya (Carica payaya) fruits on the microbiological and sensory properties od camel milk icecream. Amsterdam Oxford New York, Tokyo: Elsevier. 437 pp.

    [28]

    Drake MA, Karagul-Yuceer Y, Cadwallader KR, Civille GV, Tong PS. 2003. Determination of the sensory attributes of dried milk powder and ingredients. Journal of Sensory Studies 18:199−216

    doi: 10.1111/j.1745-459X.2003.tb00385.x

    CrossRef   Google Scholar

    [29]

    SAS. 1988. SAS\ STAT User's Guide. version 6.03. Cary, NC: SAS Institute Inc.

    [30]

    Seleem HA. 2015. Effect of blending doum (Hyphaene thebaica) powder with wheat flour on the nutritional value and quality of cake. Food and Nutrition Sciences 6:612−22

    doi: 10.4236/fns.2015.67066

    CrossRef   Google Scholar

    [31]

    Aboshora W, Lianfu Z, Dahir M, Gasmalla MAA, Musa A, et al. 2014. Physicochemical, nutritional and functional properties of the epicarp, flesh and pitted sample of Doam fruit (Hyphaene thebaica). Journal of Food and Nutrition Research 2:180−86

    doi: 10.12691/jfnr-2-4-8

    CrossRef   Google Scholar

    [32]

    Adedayo MR, Olayemi FF, Bamishaiye EI. 2011. Proximate and mineral composition of a local drink made from Baobab fruit (Adansonia digitata) pulp. Advances in Bioresearch Journal 2(2):82−85

    Google Scholar

    [33]

    De Caluwé E, Halamouá K, Van Damme P. 2010. Adansonia digitata L. – A review of traditional uses, phytochemistry and pharmacology. Afrika Focus 23(1):11−51

    doi: 10.21825/af.v23i1.5037

    CrossRef   Google Scholar

    [34]

    Adelekan AO, Saleh AA. 2020. Chemical composition and microbiological quality of Baobab (Adansonia digitata) fruit fortified yoghurt. Nigerian Journal of Microbiology 34(1):4998−5006

    Google Scholar

    [35]

    Sugandha Singh SS, Varsha Parasharami VP, Shashi Rai SR. 2013. Medicinal uses of Adansonia digitata: an endangered tree species. Journal of Pharmaceutical and Scientific Innovation 2(3):14−16

    Google Scholar

    [36]

    Eke MO, Olaitan NI, Sule HI. 2013. Nutritional evaluation of yoghurt-like product from Baobab (Adansonia digitata) fruit pulp emulsion and the micronutrient content of Baobab leaves. Advance Journal of Food Science and Technology 5(10):1266−70

    doi: 10.19026/ajfst.5.3094

    CrossRef   Google Scholar

    [37]

    Abdel-Rahman NA, Ismail IA, Elshafe'a EBB. 2015. Some quality attributes of four Sudanese forest fruits nectars. Journal of Agri-Food and Applied Sciences 3(2):32−38

    Google Scholar

    [38]

    El-Kholy WM. 2018. Preparation and properties of probiotic low fat frozen yoghurt supplemented with powdered Doam (Hyphaene thebaica) fruit. Egyptian Journal of Dairy Science 46(1):67−78

    Google Scholar

    [39]

    El-Deeb A, Dyab A, Elkot W. 2017. Production of flavoured fermented camel milk. Ismailia Journal of Dairy Science & Technology 5(1):9−20

    doi: 10.21608/ijds.2017.8070

    CrossRef   Google Scholar

    [40]

    Rozan M, Darwish AZ, Bayomy H. 2017. Effect of Roselle extract (Hibiscus sabdariffa) on stability of carotenoids. bioactive compounds and antioxidant activity of yoghurt fortified with carrot juice (Daucus carota L.). World Journal of Dairy & Food Sciences 12(2):94−101

    Google Scholar

    [41]

    Lee KJ, Kim KS, Kim HN, Seo JS, Song SW. 2014. Association between dietary calcium and phosphorus intakes dietary calcium/ phosphorus ratio and bone mass in the Korean population. Nutrition Journal 13:114

    doi: 10.1186/1475-2891-13-114

    CrossRef   Google Scholar

    [42]

    Adolfsson O, Mevdani SN, Russell RM. 2004. Yogurt and gut function. The American Journal of Clinical Nutrition 80(2):246−56

    Google Scholar

    [43]

    Abd El-Rashid, A, Hassan ZMR. 2005. Potential utilization and healthy effects of doum palm fruits in ice cream and sesame butter (Tehena). Alexandria Journal of Food Science and Technology 2:29−39

    doi: 10.21608/ajfs.2005.19609

    CrossRef   Google Scholar

    [44]

    Fasoyiro SB, Baboabla SO, Owosibo T. 2005. Chemical composition and sensory quality of fruit-flavored Roselle (Hibiscus sabdariffa) drinks. World Journal of Agricultural Sciences 1(2):161−64

    Google Scholar

    [45]

    Omemu AM, Edema MO, Atayese AO, Obadina AO. 2006. A survey of the microflora of Hibiscus sabdariffa (Roselle) and the resulting "Zobo" juice. African Journal of Biotechnology 5(3):254−59

    doi: 10.5897/AJB05.290

    CrossRef   Google Scholar

    [46]

    Sudanese Standards and Metrology Organization (SSMO). 2001. Sudanese Microbiological Standards for Foods: Bottled, Natural and Formulated Juices. No. 20. SDS 525. Khartoum, Sudan.

    [47]

    Hassan ZMR, Aumara IE. 2005. Effect of doum palm fruit (Hyphaene thebaica) on certain dairy starter cultures and undesirable icroorganisms. Annals of Agricultural Science 50:169−84

    Google Scholar

    [48]

    Turkmen N, Akal C, Özer B. 2019. Probiotic dairy-based beverages: A review. Journal of Functional Foods 53:62−75

    doi: 10.1016/j.jff.2018.12.004

    CrossRef   Google Scholar

    [49]

    Coutinho NM, Silveira MR, Fernandes LM, Moraes J, Pimentel TC, et al. 2019. Processing chocolate milk drink by low-pressure cold plasma technology. Food Chemistry 278:276−83

    doi: 10.1016/j.foodchem.2018.11.061

    CrossRef   Google Scholar

    [50]

    Law M, Huot PSP, Lee YT, Vien S, Luhovyy BL, et al. 2017. The effect of dairy and nondairy beverages consumed with high glycemic cereal on subjective appetite, food intake, and postprandial glycemia in young adults. Applied Physiology, Nutrition, and Metabolism 42(11):1201−9

    doi: 10.1139/apnm-2017-0135

    CrossRef   Google Scholar

    [51]

    Grom LC, Rocha RS, Balthazar CF, Guimarães JT, Coutinho NM, et al. 2020. Postprandial glycemia in healthy subjects: Which probiotic dairy food is more adequate? Journal of Dairy Science 103(2):1110−19

    doi: 10.3168/jds.2019-17401

    CrossRef   Google Scholar

    [52]

    Abou-Arab AA, Abu-Salem FM, Abou-Arab EA. 2001. Physico- chemical properties of natural pigments (anthocyanin) extracted from Roselle calyces (Hibiscus sabdariffa). Journal of American Science 7(7):445−56

    Google Scholar

    [53]

    El- Kholy AM. 2015. Effect of fat replacement by doam palm fruits on frozen yoghurt quality. World Journal of Dairy & Food Sciences 10:74−81

    doi: 10.5829/idosi.wjdfs.2015.10.1.94204

    CrossRef   Google Scholar

  • Cite this article

    Saied MNAM, El Zubeir IEM. 2024. Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits. Food Materials Research 4: e016 doi: 10.48130/fmr-0024-0007
    Saied MNAM, El Zubeir IEM. 2024. Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits. Food Materials Research 4: e016 doi: 10.48130/fmr-0024-0007

Figures(2)  /  Tables(6)

Article Metrics

Article views(2430) PDF downloads(404)

Other Articles By Authors

ARTICLE   Open Access    

Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits

Food Materials Research  4 Article number: e016  (2024)  |  Cite this article

Abstract: The loss of valuable nutrient content of the whey proteins obtained from the dairy industry in general is disposed of causing sewage pollution. Therefore, this study aims to utilize the nutrient content of whey proteins to beverages using some Sudanese indigenous fruits: Baobab (Adansonia digitata L.), Roselle (Hibiscus sabdariffa L.) and Doum (Hyphaene thebaica) juices at a rate of 30:70, 50:50 and 70:30% for preparation of beverages. The processed beverages were evaluated for some chemicals, microbial, and sensory properties. Whey proteins enriched with Doum juice revealed significantly (p ≤ 0.05) high-fat level (0.93%), while that enriched with Roselle was significantly (p ≤ 0.05) higher in the protein value (5.97%). Whey proteins enriched with Baobab juice significantly (p ≤ 0.05) revealed a higher value for vitamin C (140.93 mg/100 mL). The values obtained for calcium and phosphorus were significantly (p ≤ 0.05) high in the whey enriched with Roselle juice (8.50 and 1.29 mg/100 mL, respectively). The heat treatment of whey proteins showed significant (p ≤ 0.05) reduction in the total viable bacterial counts. Moreover, the lactic acid bacteria were higher in plain whey proteins followed by those enriched Roselle and Baobab juices. Also, the whey proteins enriched with Roselle juice showed significantly (p ≤ 0.05) the best color. However, the whey proteins enriched with Doum juice significantly (p ≤ 0.05) revealed the best scores for flavor and taste. Hence, the present study concluded that it is possible to use some indigenous Sudanese fruits to utilize the whey proteins as functional food instead of its negative effect on the environment.

    • Milk proteins are the best protein source because of their essential amino acid score that helps in improving the protein digestibility corrected amino acids scores. The high quality protein content of both whey proteins (20%) and caseins (80%) are satisfying the requirements of human amino acid needs in addition to their digestibility and bioavailability[1].

      Whey proteins are precious watery nutrients as they contain about half of the milk total solids that remain after the caseins are curdled during cheese making, it is a rich source of lactose, whey proteins, some milk salt and water-soluble vitamins[2]. Whey proteins are well-documented as valuable milk ingredients and are highly nutritious food[3]. Moreover, the nutraceutical properties that are derived from the metabolic hydrolysis of milk, its whey proteins, and their peptides include antimicrobial and antioxidant activities[4]. Additionally, the preventive and curative effects that the protein possess have practical applications in the treatment of anemia, liver complaints, and arthritis[5].

      During cheese making, the valuable whey proteins that are lost while separating the whey from the milk[3], could be converted into attractive fermented or non-fermented products for human utilization and consumption[6]. For example, the use of advanced filtration techniques for valorization of whey cheese was found to recover these high value proteins[7,8].

      Baobab (Adansonia digitata L.) is a grossly indigenous fruits[9]. Baobab fruit pulp obtained from the different regions of Sudan were found to contain high vitamin C (358.44 mg/100 g), calcium (393.55 mg/100 g) and phosphorus (91 mg/100 g) levels, in addition to their high protein content (5.2%)[10]. Baobab fruit pulp exhibits higher antioxidant properties[11]. Dry Baobab pulp in Sudan, is either eaten fresh, ground to prepare a refreshing drink, added to gruel during its cooling[10] or as flavor to ice cream[12,13].

      Roselle (Hibiscus sabdariffa L.) belongs to the family Malvaceae, an annual shrub that is grown in many tropical or subtropical countries including Sudan. Moreover, the red calyces of Roselle are usually used for preparing a flavorful and tart beverage either cold or hot to utilize their rich content of the numerous beneficial bioactive compounds[14]. In Sudan, Roselle is grown extensively in Darfur and Kordofan states under rained conditions[15]. Roselle has antimicrobial antispasmodic and hypotensive effects as well as for uterine muscle relaxation[16]. The phytochemical content of Rosella that are reflected in the health of consumers enables its use in many functional food[17].

      Doum palm (Hyphaene thebaica) is a palm tree adapted to the desert and it has edible oval fruit with a potent antioxidants activity due to its high content of polyphenols[18]. The fruits of Doum palm (Hyphaene thebaica) are rich in dietary fibers and carbohydrates and it contains anti-hypertension substances[19]. Moreover, the edible portion of Doum fruits showed good values for dietary fiber and vitamins B1, B3, and B6, besides the total phenolic and flavonoid contents and its antioxidant activity that encourage its use in the formula of some functional foods[20]. Therefore, the objectives of the present study are the utilization of whey proteins produced by the dairy industry to develop whey-based beverages using some of the Sudanese indigenous fruits (Roselle, Baobab, and Doum palm) and test the quality of the obtained products. The gross chemical composition and the levels of vitamin C, calcium and phosphorus were compared within different whey proteins based beverages. Also the microbial content and some sensory attributes were compared for the different produced whey proteins beverages

    • The liquid whey remaining after the processing of Mozzarella cheese were obtained from the Dairy Production Department, Faculty of Animal Production, University of Khartoum, Sudan.

    • Roselle (Hibiscus sabdariffa L.) powder, Baobab (Adansonia digitata L.) powder, Doum palm (Hyphaene thebaica) powder, sugar and Gum Arabic were bought from the markets of Khartoum, Sudan.

    • Three liters of whey proteins were obtained after making Mozzarella cheese and sieved before being subjected to heating for 15 min at 75 °C. They were left to cool at a temperature of 10 °C. After that, they were filtrated using a clean cheesecloth and stored at room temperature.

    • Sixty grams of Roselle (Hibiscus sabdariffa L.) powder was socked into 200 mL distilled water for 24 h and then filtrated. Meanwhile, 15 g of each Baobab (Adansonia digitata L.) and Doum (Hyphaene thebaica) powder were separately dissolved in 200 mL of clean distilled water. Then the three prepared juices were added to make different whey proteins beverages.

    • During this experiment, 10 different whey proteins beverages were developed based on 3 different treatments in addition to the control (Plain whey proteins). The three treatment utilized 30:70%, 50:50%, and 70:30% of the heated liquid whey proteins that were added to the selected fruit juices. After making all the mixtures of the whey proteins and the fruits juices, about 15 g of sugar and 2.5 g of Gum Arabic were added to each of the prepared fruit juices and each was blended separately.

    • The chemical composition of whey protein beverages was performed according to the methods of the AOAC[21].

      The fat content was extracted by taking 10.94 mL of the whey proteins beverages sample and 10 mL sulfuric acid (density 1.815 gm/mL at 20 °C) into a clean dry Gerber. Then 1 mL of amyl alcohol (density 0.814–0.816 gm/mL at 20 °C) were added and the contents were thoroughly mixed till no white particles could be seen. After the centrifugation of the Gerber tubes (1,100 revolution per min) for 3 min, they were transferred into a water bath at 65 °C for 3 min and then the fat percent was taken directly from the fat column[21].

      The total protein content of the whey protein beverages was determined using the Kjeldahl method[21]. In a clean and dry Kjeldahl flask, 10 mL of the whey proteins beverages sample was placed followed by the addition of catalyst powder (Na2SO4 and the equivalent of 0.1 mg Hg). Then 25 mL concentrated sulfuric acid (density 1.86 gm/mL at 20 °C) was added to the flask and the mixture was then digested on a digestion heater until a clear solution was obtained (3 h). The flasks were then removed and left to cool and the digested samples were poured into volumetric flasks (100 mL) and diluted to 100 mL with distilled water. About 5 mL were taken and neutralized using 10 mL of 40% NaOH. The distillate was received into a conical flask containing 25 mL of 2% boric acid and 3 drops of 0.1 of bromocresol green and methyl red) indicator. This distillation was continued until the volume in the flask was 75 mL. The flasks were then removed from the distillates and titrated against HCl (0.1N) until the endpoint was obtained (red color). The protein content was calculated as follows:

      Nitrogen(%)=T×0.1×20×0.014Weightofsample×100
      Protein(%)=Nitrogen(%)×6.38

      Where, T: itration figure; 0.1: Normality of HCl; 0.014: Atomic weight of nitrogen; 20: Dilation factor.

      The content of lactose was determined using the anthrone method[22]. The reagent was added to the clear filtrate from precipitation of a sodium bicarbonate solution of the whey protein beverages with 0·1 n-sulphuric acid. The reagent consists of 0.15% (w/v) anthrone in 70% (v/v) sulphuric acid. Ten mL of the ice-cold anthrone solution was added, with cooling, to 1 mL of the ice-cold solution containing 0–100 µg of lactose. The mixture was heated at 100 °C for 6 min and then cooled for 30 min. The optical density of the colored solution was then measured at 625 nn using spectrophotometer (UV mini 1240), Shimadzo, Japan.

      The titratable acidity of whey proteins beverages was determined by taking 10 mL of the sample into a white porcelain dish and then 0.5 mL of phenolphthalein indicator was added. The titration was conducted using 0.1 N NaOH until a faint pink color that lasted for 30 s was obtained. The titration figures were then divided by 10 to get the percentage of the lactic acid[21].

      The ash content was determined according to the AOAC method[21] by weighing 5 mL of whey protein beverages sample into a suitable clean dry crucible and evaporating to dryness on a steam bath. The crucibles were placed in a muffle furnace at 550 °C for 1.5–2 h. It was cooled in a desiccator and weighted. The ash content was then calculated as follows:

      Ash(%)=W1W2×100

      Where, W1= Weight of ash; W2= Weight of sample.

      The solid's non-fat content where then calculated mathematically by adding the sum of lactose, protein, and ash content.

      Vitamin C content of the whey protein beverage samples (in duplicate) was determined by the method developed previously[23] using a UV/VIS Spectrophotometer (UNICAM, 8625).

      For the determination of calcium and phosphorus of whey proteins beverages samples, the residual of the ash extract was used. The phosphorus was determined by spectrophotometer (UV mini 1240), Shimadzo, Jaban. The estimation of phosphorous content was conducted using the vanadate-molybdate yellow calorimetric method[24]. Also the the calcium content was performed as was described previously[24]. The calcium content was determined by taking 5 mL of the ash extract solution into a 50 mL conical flask and the volume was completed to 25 mL by distilled water. Then 50 mg of meroxide indicator, 3−5 drops of sodium hydroxide were added, and the mixture was titrated against 0.01 N (EDTA). After calibration, the solution changed from pink to purple.

      Ca+Mgmmol/L=(V×N×1000)/5mL
      Cammol/L=(V×N×1000)/5mL

      Where, N: normality of EDTA; V: volume.

    • Plate count agar (Biomark, B 298) medium was used to determine the total bacterial count at 32 °C for 48 h. It was obtained in a dehydrated form and each rehydrated liter of the medium was composed of casein enzymic hydrolysate (5.0 g), yeast extract (2.5 g) dextrose (1.0 g), and agar (15.0 g). According to the manufacturers' instructions, 23.5 g were suspended in 1,000 mL distilled water; it was boiled until dissolved completely and sterilized

      The M17 broth media (HIMEDIA, M1029-500G) medium was obtained in dehydrated form and it was used for the enumeration of the lactic acid bacterial count after solidifying with the agar. This medium consists of casein enzymic hydrolysis 2.50 g/L, peptic digest of animal tissue 2.50 g/L, peptic digest of soyabean meal 5.00 g/L, yeast extract 2.50 g/L, beef extract 5.00 g/L, ascorbic acid 0.50 g/L, magnesium sulphate 0.25 g/L, lactose 5.00 g/L and disodium-B-glycerophosphate 19.00 mg/L. The final pH was adjusted to 7.1 ± 0.1 at 25 °C. About 42.25 g were suspended in 1,000 mL distilled water. The medium was dissolved completely and 13 g of the agar was added before the sterilization.

      The manufacturer' instructions were followed carefully for the preparation of both media, they were sterilized using the autoclave (15-pound pressure for 15 min)[25]. Similarly, the mixer, tips, and distilled water were sterilized using the autoclave (15 min at 121 °C)[25]. However, sterilization of glassware; Petri- dishes, test tubes, pipettes, flasks, and bottles; were done using dry heat (hot oven) at 160 °C for 1 h.

      The plate count agar medium was incubated at 32 °C for 48 h[26] and the lactic acid bacterial count was determined at 37 °C anaerobically for 24 h on M17 agar[27]. A colony counter was used to count the different types of colonies and the results were present as cfu/mL.

    • The sensory evaluation was conducted according to a previously described method[28]. All the obtained data were evaluated using the penal test sheets.

    • The obtained data were subjected to Statistical Analysis Systems (SAS). A comparison of means was performed using Duncan Multiple Range test (p ≤ 0.05)[29]. A Microsoft Excel sheet was used to plot the figures.

    • The data obtained for the chemical composition of whey proteins beverages (Table 1) showed that the fat content in the different juices used was less than that obtained for the plain whey proteins. However, significantly (p ≤ 0.05) higher fat content was found in the whey enriched with Doum juice (0.93%) compared to other juices. This might be because the fruits of Doum palm have a slightly high content of fat (2.57%)[30]. Moreover, the functional properties of the essential nutrients that are possessed and provided by Doum fruits have an important role in addressing many problems related to food in patients with diabetic and hypertensive conditions[31]. The low values of the fat in the Baobab fruit pulp is the reason for the lowest mean obtained for fat content in whey proteins enriched with Baobab[13].

      Table 1.  Effect of fruits type on the chemical composition of whey proteins beverages.

      ParametersPlain whey proteinsWhey enriched with Baobab juiceWhey enriched with Roselle juiceWhey enriched with Doum juice
      Fat (%)1.03a0.71b0.36c0.93a
      Protein (%)4.45b1.41c5.79a5.33ab
      SNF (%)8.59c17.98a15.40b16.39ab
      Lactose (%)4.78d16.36a8.30c9.99b
      Acidity (%)0.48b0.38c0.30d0.58a
      Means with the same superscripts letters in the same column are not significantly different (p > 0.05).

      Significantly (p ≤ 0.05) higher protein content was obtained in whey proteins enriched with Roselle juice (5.79) followed by that enriched by Doum juice (5.33%) compared to the plain whey proteins (Table 1). Moreover, the proportion of protein content (6.46% and 6.29%) was found to increase with increasing of Doum juice (70% and 50%, respectively) as shown in Table 2 and this might be due to the protein content of Doum palm, which revealed 7.05%[30]. Also, the plain whey proteins revealed 4.45% proteins (Tables 1 & 2). Whey proteins contain highly nutritious food ingredients[3].

      Table 2.  Comparison of the chemical composition of whey proteins beverages using different type and concentration of fruits.

      ParametersConcentrations (%)Fat (%)Protein (%)SNF (%)Lactose (%)Acidity (%)
      Plain whey proteins1.034.458.594.480.48
      Whey enriched with Baobab juice30:700.1718.4817.930.50
      50:502.130.3618.0017.160.37
      70:303.6917.1413.980.28
      Whey enriched with Roselle juice30:700.235.818.318.430.19
      50:500.175.8112.318.310.33
      70:300.145.7415.388.250.34
      Whey enriched with Doum juice30:700.266.4617.099.240.28
      50:500.256.2916.268.420.17
      70:300.083.2415.818.250.10

      The solid non-fat content of whey protein beverages revealed significantly (p ≤ 0.05) higher values for the whey protein beverages enriched with Baobab pulp (17.98%), followed by that enriched with Doum juice (16.39%) and Roselle juice (15.40%) compared to the plain whey proteins (8.59%). This could be because the Baobab fruit has a high content of carbohydrates (21.09%)[32]. Moreover, the carbohydrate content of dry Baobab fruit pulp is relatively high[33]. The reason could be because the total solids content of Baobab pulp are high[13].

      The significant (p ≤ 0.05) high lactose content (16.36%) was reported for the whey proteins enriched using Baobab juice (Table 1). This could be justified by the fact that the dry fruit pulp of Baobab is a rich source of carbohydrates[33].

      The titratable acidity in the whey enriched with Baobab revealed the highest significant (p ≤ 0.05) value (0.58%) followed by that obtained for the plain whey proteins (0.48%). The obtained higher value justified the use of Baobab in the fermentation of some foods. The obtained titratable acidity (0.38%−0.42%) in yogurt was found to comply with the required minimum standard (0.6%) stated for commercial yogurt[34].

      Table 3 showed significant (p ≤ 0.05) variations in the values of vitamin C in the different whey protein beverages. The significant (p ≤ 0.05) high content of vitamin C was found for Baobab enriched whey proteins (140.93 mg/100 mL). The obtained higher levels of vitamin C demonstrated the antioxidant properties of the three used fruit juices (Tables 3 & 4). Moreover, vitamin C content was found to increase with the increasing proportion of the Baobab juice extracts (167.22 and 166.39 mg/100 mL for 70% and 50%, respectively). The high vitamin C content of the raw Baobab fruit pulp justified these findings[10,11,33,34]. The value of vitamin C was found to increase with the increasing fortification level of Baobab pulp into yogurt[34]. Moreover, the high natural content of vitamin C in the pulp of Baobab fruit, enables its good antioxidant activity[35]. Vitamin C and A in Baobab fruit pulp were estimated as 236 and 80 mg/100 mL, respectively[36].

      Table 3.  Effect of fruit types on vitamin C and some minerals contents of whey proteins beverages.

      ParametersWhey enriched with Baobab juiceWhey enriched with Roselle juiceWhey enriched with Doum juice
      Vitamin C (mg/100 mL)140.93a91.28c129.28b
      Phosphorus (mg/100 mL)0.90b1.29a0.94b
      Calcium (mg/100 mL)1.23b8.50a0.93c
      Means bearing similar superscripts letters in the same column are not significantly different (p > 0.05).

      Table 4.  Effect of fruits type and concentration on the vitamin C and some minerals contents of whey proteins beverages.

      ParametersConcentrations
      (%)
      Vitamin C
      (mg/
      100 mL)
      Phosphorus
      (mg/
      100 mL)
      Calcium
      (mg/
      100 mL)
      Whey enriched with Baobab juice30:70167.220.870.70
      50:50166.390.591.40
      70:3089.190.551.60
      Whey enriched with Roselle juice 30:7056.241.232.30
      50:50101.231.852.30
      70:30116.252.110.90
      Whey enriched with Doum juice30:70156.170.731.30
      50:50139.440.980.80
      70:3092.221.130.70

      High level of vitamin C in Doum juice extract (129.28 mg/100 g) was also found during this study (Table 3). However, a lower value (31.74 mg/100 g) was reported for Doum fruit nectar samples[37]. This supported the fact that Doum fruit contains potent antioxidants[18]. Moreover, in a different product, it was reported that adding various percentages of powdered Doum fruit resulted in a proportional increase in the content of the total phenol as well as the antioxidant of the low-fat frozen yogurt compared with the control[38]. Also, the fermented milk of camel that was flavored using concentrated extracts of Doum was found to cause a significant increase in the content of phenolic components that showed correlation with the concentrations of the added levels of the juices[39]. On the other hand, the red pigment of Roselle showed a higher antioxidant activity when the fruit is consumed as beverages and the added Roselle extract resulted in more increase of the total phenolic content of yogurt fortified with different levels of Roselle extract and carrot juice[40].

      The calcium content that was obtained in the whey proteins enriched with the Roselle juice (8.50 mg/100 mL) revealed significantly (p ≤ 0.05) higher values (Tables 3 & 4). This might be because the Roselle extract is slightly higher in calcium content as was reported previously[41]. Similarly, high calcium content was obtained for the whey proteins enriched with the Baobab fruit juice extract supported the report, which stated that the fruit pulp of dry Baobab has a high content of calcium and vitamin C[33]. The Baobab fruit pulp contains about 295 mg/100 g of calcium[10]. The range of calcium in the Baobab was 4.10−4.30 mg/100 g[36]. The calcium requirements during growth, pregnancy, and lactation are increased[42]. Therefore, yogurt enriched the Baobab as a drink would be beneficial in maintaining the high calcium requirements for pregnant women, lactating mothers, children, and the elderly[34]. On the other hand, powdered Doum fruit contains adequate K, Ca, Na, and Mg[20,31,38]. Utilization of Doum palm (Hyphaene thebaica) powdered fruit showed useful application in food products because of its fiber and mineral content and its potential in health[43].

      The content of phosphorus reported for the whey proteins enriched with Roselle juice (1.29 mg/100 mL) showed significant (p ≤ 0.05) high values (Table 3). The phosphorus content was found to increase with increasing the used proportion of Roselle juice (Table 4). This reflected the richness of Roselle juice in its phosphorus content (2.78 mg/100 mL)[44]. However, the Baobab fruit content for phosphorus was in a range of 1.70−1.90 mg/100 g[36]. Among humans, a high content of phosphorus is desirable for increasing bone health[41].

    • The microbial analysis of whey beverages (Table 5; Fig. 1) showed a high count for the total viable bacteria in the whey protein before heat treatment (log 5.10 vs 2.58), which matches very well with the objectives of heat treatment as a preservation method. The whey proteins enriched with Doum juice showed the lowest result for the total viable bacteria count (Table 5; Fig. 1). It was reported that Doum nectar did not show any viable bacteria during the storage period at the ambient and refrigeration temperatures[37]. Also, the antimicrobial activity of Hibiscus extracts against many bacteria was reported. Hence the extracts of H. sabdariffa have the potential to be used as antimicrobials in a food beverage system[14]. Information on microflora associated with the dried calyx of H. sabdariffa and its Zobo juice will help in designing appropriate techniques for the preservation of the juice[45]. The Hibiscus extracts have a potential use in the prevention of pathogenic growth in foods and beverages[14].

      Table 5.  Effect of fruits type and concentration on the microbiological loads of whey proteins beverages.

      ParametersConcentrations (%)Total violet bacterial countLactic acid bacterial count
      Whey proteins
      before heat
      treatment
      (Control A)
      5.103.72
      Whey proteins
      after heat
      treatment
      (Control B)
      2.582.49
      Whey enriched with Baobab juice30:703.692.99
      50:504.243.06
      70:303.263.00
      Whey enriched with Roselle juice30:703.283.17
      50:504.653.12
      70:303.273.07
      Whey enriched with Doum juice30:702.672,53
      50:503.093.48
      70:302.672.53

      Figure 1. 

      Variations of the microbiological loads of whey proteins beverages using different types and concentrations of fruits.

      The total viable account was intermediate in whey proteins enriched with Baobab (Table 5; Fig. 1). Similarly, the 5% Baobab ice cream revealed a low total bacterial count compared to that made using 3% Baobab, which is indictive of its antimicrobial action[12]. This might be because its fruit pulp has higher values of vitamin C in addition to its antioxidant activity that play a positive role in reducing the microbial loads and hence extending the shelf-life of foods and beverages[32,35]. The microbial levels in formulated fruit juices should be 102 to 103 cfu/mL) according to the standards of the Sudanese Standards and Meteorology Organization[46].

      The lactic acid bacteria were higher in whey proteins enriched with Roselle fruit juice (Table 5; Fig. 1). This might be because the Roselle fruit juice extract is slightly higher in acidity content than other fruits used (Tables 1 & 2), which supported a previous findings[44]. Also, the present findings supported the previous report, which stated that the use of Doum palm extracts in the aqueous form will lead to the increase of both viability and activity of probiotics dairy starter cultures that are used in the manufacture of some special dairy products[47]. Moreover, the whey proteins drawn from cheese and buttermilk provide a suitable matrix for enhancing the growth and viability of probiotic microorganisms for the potential development of probiotic dairy-based beverages[48].

      In this study the base of the whey protein beverages is the Mozzarella cheese, hence some of the estimated useful lactic acid bacteria in the different whey proteins enriched juices are rich. This also supported the functional properties of the prepared juices as the health benefits of the starter cultures as a probiotic is well documented. The dairy-based whey proteins beverages display many health benefits because of their high contents of the antioxidant activity, bioactive peptides and the essential amino acids present in the whey[48,49]. In addition to their role in the mitigation of blood glucose and decreased appetite[50]. Thus, consuming dairy products enriched with probiotics provide anti-hyperglycemic effect and many other health benefits that depend upon the type of probiotic culture used and the consumed dairy products[51].

    • The sensory organoleptic evaluation of whey proteins beverages (Table 6; Fig. 2) showed that the whey proteins enriched with Roselle juice showed significantly (p ≤ 0.05) high acceptable score for color and this is because of its red color, which is due to the anthocyanins present in Roselle fruit[52]. When the extracts of Hibiscus are made into beverages or juice, its red color gained the desirability of the consumers[14]. The addition of Roselle extract (0.2%–0.4%) to carrot juice was found to improve the functional properties of yogurt and increased its sensory scores for up to 21 d[40]. Moreover, the US Food and Drug Administration has accepted H. sabdariffa as a natural flavoring substance because their calyces are extracted in water[14]. However, the whey enriched with Doum juice was significantly (p ≤ 0.05) high acceptable for its taste followed by Baobab. Similarly, higher scores were estimated for the sensory attributes with the addition of up to 33% powdered Doum fruit[38].

      Table 6.  Comparison of the sensory characteristics of whey proteins beverages using different types and concentrations of fruits.

      Fruit juiceConcentrations (%)ColorFlavorTaste
      Whey proteins enriched with Baobab juice30:701.702.602.30
      50:501.502.202.50
      70:302.502.601.60
      Whey proteins enriched with Roselle juice30:702.101.802.25
      50:501.802.452.45
      70:301.952.252.25
      Whey proteins enriched with Doum juice30:701.202.252.65
      50:501.452.253.00
      70:302.302.102.50

      Figure 2. 

      Variations of the sensory characteristics of whey proteins beverages using different fruits.

      Significantly (p ≤ 0.05) higher scores were reported in the flavor of whey proteins enriched with Baobab (Table 6; Fig. 2). This is in line with the conclusion stating that adding 3% Baobab to camel milk ice cream resulted in an improvement of its flavor[12]. The significantly (p ≤ 0.05) high acceptability of Doum juice could be because using Doum palm fruit gave the product a sweet taste, special flavour, and colour[53]. Hence, there is a possibility of producing high quality fermented milk from camel with good appearance, colour, flavour, body and texture when adding Doum extract[39].

    • Variations reported for some of the compositional contents of the obtained whey protein beverages might be due to the different chemical composition of fruits used. The sensory evaluation showed the best result of the whey proteins enriched with the fruits of Doum palm (Hyphaene thebaica). The possibility of using some of the valuable Sudanese local fruits should be promoted and utilized for enriching the whey protein. This will help in improving the nutritional content and acceptability of the selected fruit juices and the whey proteins and thus contribute globally to obtain functional foods.

    • The contribution of the authors regarding this paper was as follows: study conception and design: Saied MNAM, El Zubeir IEM; collection of data: Saied MNAM; analysis and interpretation of the results: Saied MNAM; draft manuscript preparation: Saied MNAM, El Zubeir IEM. Both authors reviewed and approved the final version of the manuscript.

    • The data generated and analyzed during the current study are available from the corresponding author (Ibtisam E. M. El Zubeir) on reasonable request.

    • The authors would like to extend their acknowledgments to the staff members in the Department of Dairy Production, Faculty of Animal Production, U. of K. for their technical help during the laboratory work.

      • The authors declare that they have no conflict of interest.

      • Copyright: © 2024 by the author(s). Published by Maximum Academic Press on behalf of Nanjing Agricultural University. This article is an open access article distributed under Creative Commons Attribution License (CC BY 4.0), visit https://creativecommons.org/licenses/by/4.0/.
    Figure (2)  Table (6) References (53)
  • About this article
    Cite this article
    Saied MNAM, El Zubeir IEM. 2024. Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits. Food Materials Research 4: e016 doi: 10.48130/fmr-0024-0007
    Saied MNAM, El Zubeir IEM. 2024. Utilization of whey proteins in beverages using Baobab (Adansonia digitata L.), Roselle (Adansonia digitata L.) and Doum (Hyphaene thebaica) fruits. Food Materials Research 4: e016 doi: 10.48130/fmr-0024-0007

Catalog

  • About this article

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return