Figures (8)  Tables (3)

    • Figure 1. 

      Results of (a) total mesophilic count, (b) total psychrotrophic count, (c) nitrogen of total volatile bases (TVB-N) and trimethylamine (TMA), (d) pH, (e) melanosis index, (f) total quality index obtained in samples of white shrimp (L. vannamei), packed in atmospheric air, submitted to different antimelanosic treatments, stored for 21 d (4 ± 1 °C). C-AIR: without immersion bath, packed with atmospheric air; SMS-AIR: immersion in 1.25% SMS, packed with atmospheric air; AF-AIR: immersion in 10% acerola fruit solution, packed with atmospheric air; Error bars represent the standard error of three replicates.

    • Figure 2. 

      Photographs of white shrimp (L. vannamei) packed in atmospheric air, submitted to different antimelanosic agents, and stored for 21 d (4 ± 1 °C). C-AIR: without immersion bath, packed with atmospheric air; SMS-AIR: immersion in 1.25% SMS, packed with atmospheric air; AF-AIR: immersion in 10% acerola fruit solution, packed with atmospheric air (photographs were taken after the shrimp were removed from their packaging for sensory evaluation).

    • Figure 3. 

      Results of (a) total mesophilic count, (b) total psychrotrophic count, (c) nitrogen of total volatile bases (TVB-N) and trimethylamine (TMA), (d) pH, (e) melanosis index, (f) total quality index obtained in samples of white shrimp (L. vannamei), without different antimelanosic treatments, stored for 21 d (4 ± 1 °C). C-AIR: without immersion bath, packed with atmospheric air; C-MAP1: without immersion bath, packed with modified atmosphere1; C-MAP2: without immersion bath, packed with modified atmosphere 2; C-VAC: without immersion bath, packed with vacuum pack; Error bars represent the standard error of three replicates.

    • Figure 4. 

      Photographs of white shrimp (L. vannamei) without different antimelanosic treatments, stored for 21 d (4 ± 1 °C). C-AIR: without immersion bath, packed with atmospheric air; C-MAP1: without immersion bath, packed with modified atmosphere1; C-MAP2: without immersion bath, packed with modified atmosphere 2; C-VAC: without immersion bath, packed with vacuum pack (photographs were taken after the shrimp were removed from their packaging for sensory evaluation).

    • Figure 5. 

      Results of (a) total mesophilic count, (b) total psychrotrophic count, (c) nitrogen of total volatile bases (TVB-N) and trimethylamine (TMA), (d) pH, (e) melanosis index, (f) total quality index obtained in samples of white shrimp (L. vannamei) submitted to 1.25% sodium metabisulfite (SMS) treatment, packed in different atmospheric air, and stored for 21 d (4 ± 1 °C). SMS-AIR: packed with atmospheric air; SMS-MAP1: packed with modified atmosphere (70% N2 : 25% CO2 : 5% O2); SMS-MAP2: packed with modified atmosphere (25% N2 : 70% CO2 : 5% O2); SMS-VAC: vacuum packed. Error bars represent the standard error of three replicates.

    • Figure 6. 

      Photographs of white shrimp (L. vannamei) submitted to 1.25% sodium metabisulfite (SMS) treatment, packed in different atmospheric air, and stored for 21 d (4 ± 1 °C). SMS-AIR: packed with atmospheric air; SMS-MAP1: packed with modified atmosphere (70% N2 : 25% CO2 : 5% O2); SMS-MAP2: packed with modified atmosphere (25% N2 : 70% CO2 : 5% O2); SMS-VAC: vacuum packed. Error bars represent the standard error of three replicates (photographs were taken after the shrimp were removed from their packaging for sensory evaluation).

    • Figure 7. 

      Results of (a) total mesophilic count, (b) total psychrotrophic count, (c) nitrogen of total volatile bases (TVB-N) and trimethylamine (TMA), (d) pH, (e) melanosis index, (f) total quality index obtained in samples of white shrimp (L. vannamei) submitted to 10% acerola fruit (AF) treatment, packed in different atmospheric air, and stored for 21 d (4 ± 1 °C). AF-AIR: packed with atmospheric air; AF-MAP1: packed with modified atmosphere (70% N2 : 25% CO2 : 5% O2); AF-MAP2: packed with modified atmosphere (25% N2 : 70% CO2 : 5% O2); AF-VAC: vacuum packed. Error bars represent the standard error of three replicates.

    • Figure 8. 

      Photographs of white shrimp (L. vannamei) submitted to 10% acerola fruit (AF) treatment, packed in different atmospheric air, and stored for 21 d (4 ± 1 °C). AF-AIR: packed with atmospheric air; AF-MAP1: packed with modified atmosphere (70% N2 : 25% CO2 : 5% O2); AF-MAP2: packed with modified atmosphere (25% N2 : 70% CO2 : 5% O2); AF-VAC: vacuum packed (photographs were taken after the shrimp were removed from their packaging for sensory evaluation).

    • Package conditionsControlSodium metabisulphiteAcerola fruit
      Air (Atmospheric air)C-AIRSMS-AIRAF-AIR
      MAP1 (70% N2 : 25% CO2 : 5% O2)C-MAP1SMS-MAP1AF-MAP1
      MAP2 (25% N2 : 70% CO2 : 5% O2)C-MAP2SMS-MAP2AF-MAP2
      VacuumC-VACSMS-VACAF-VAC
      C-AIR: without immersion bath, packed with atmospheric air; SMS-AIR: immersion in 1.25% sodium metabisulphite (SMS), packed with atmospheric air; AF-AIR: immersion in 10% acerola fruit solution, packed with atmospheric air; C-MAP1: without immersion bath, packed with modified atmosphere1; SMS-MAP1: immersion in 1.25% SMS, packed with modified atmosphere 1; AF-MAP1: immersion in 10% acerola fruit solution, packed with modified atmosphere 1; C-MAP2: without immersion bath, packed with modified atmosphere 2; SMS-MAP2: immersion in 1.25% SMS, packed with modified atmosphere 2; AF-MAP2: immersion in 10% acerola fruit solution, packed with modified atmosphere 2; C-VAC: without immersion bath, packed with vacuum pack; SMS-VAC: immersion in 1.25% SMS, packed with vacuum; AF-VAC: immersion in 10% acerola fruit solution, packed with vacuum. All packages were composed of a Combitherm® film (Wolff Walsrode AG, Germany) 0.115 mm thick and grammage 115.0 g·m−2, with the following gas permeability characteristics: water vapor 2.5 g·m−2·day−1; nitrogen <0.1 cm3·m−2·day−1·bar−1; oxygen 0.8 cm3·m−2·day−1·bar−1; carbon dioxide 0.8 cm3·m−2·day−1·bar−1.

      Table 1. 

      Treatment combinations of samples submitted to antimelanosic and packaging systems.

    • Quality
      parameter      		DescriptionScore
      OdorFresh, smooth as seaweed0
      Faint, reminiscent of sea salt2
      Light ammonia sent4
      Heavy ammonia sent, putrid6
      MelanosisAbsent0
      Slight, small isolated black spots, occurring in up to 50% of the sample's shrimp2
      Moderate, small isolated black spots, occurring in over 50% of the sample's shrimp4
      Moderate, larger black stains, occurring in up to 50% of the sample's shrimp6
      Heavy, larger black stains, occurring in over 50% of the sample's shrimp8
      Heavy, blackening of the shrimp, occurring in 100% of the sample's shrimp10
      TextureNormal0
      Softened2
      ShellStrongly adhered0
      Mildly adhered2
      Weakly adhered4
      HeadStrongly adhered0
      Mildly adhered2
      Weakly adhered4
      AppearanceExcellent0
      Great2
      Good4
      Bad6
      Awful8
      Unacceptable10
      Total Quality Index (TQI)0−36
      Adapted from Oliveira et al.[20] .

      Table 2. 

      QIM scheme developed especially for this research.

    • GroupsLinear regression modelr2Shelf life (d)
      C-AIRy = 10.67 + 1.1890 x0.879510.7(See Fig. 1e)
      SMS-AIRy = 3.30 + 1.3670 x0.849714.7
      AF-AIRy = 5.70 + 1.2860 x0.945613.7
      C-AIRy = 10.67 + 1.1890 x0.879510.7(See Fig. 3e)
      C-MAP1y = 9.50 + 1.1330 x0.918412.3
      C-MAP2y = 11.63 + 0.9110 x0.840312.9
      C-VACy = 9.53 + 1.0250 x0.879613.5
      SMS-AIRy = 3.30 + 1.3670 x0.849714.7(See Fig. 5e)
      SMS-MAP1y = 6.30 + 1.1095 x0.762415.4
      SMS-MAP2y = 2.83 + 1.2310 x0.820016.7
      SMS-VACy = 1.23 + 1.1970 x0.950018.5
      AF-AIRy = 5.70 + 1.2860 x0.945613.7(See Fig. 7e)
      AF-MAP1y = 7.17 + 1.1510 x0.931714.1
      AF-MAP2y = 6.84 + 1.1476 x0.903514.4
      AF-VACy = 3.67 + 1.3420 x0.887914.7
      y = maximum acceptable TQI (65% of total, i.e., 23.4); x = refrigerated days; r2 = coefficient of determination.

      Table 3. 

      Results from the linear regression and estimated shelf life after 21 d of storage (4 ± 1°C).