Effect of storage at elevated temperature on the quality and stability of different almond oils: a comprehensive study

Ahmed Raza Sidhu; Saba Naz; Sarfaraz Ahmed Mahesar; Aftab Ahmed Kandhro; Abdul Rauf Khaskheli; Zafar Ali; Hina Daud Memon; Hadia Shoaib; Habib ur Rehman Mahesar; Ahmed Raza Sidhu; Saba Naz; Sarfaraz Ahmed Mahesar; Aftab Ahmed Kandhro; Abdul Rauf Khaskheli; Zafar Ali; Hina Daud Memon; Hadia Shoaib; Habib ur Rehman Mahesar

doi:10.48130/FMR-2023-0030

Figures (7) Tables (2)

Figure 1.
Changes in FFA values of almond oil during forced oxidation of 21 d.
Figure 2.
Changes in PV values of almond oil during forced oxidation of 21 d.
Figure 3.
Changes in p-AV values of almond oil during forced oxidation of 21 d.
Figure 4.
Changes in TOTOX values of almond oil during forced oxidation of 21 d.
Figure 5.
FT-IR group spectra (a) Australian, (b) American and (c) Iranian almond kernel oil samples at different days.
Figure 6.
Representative GC-MS chromatograms of fresh almond kernel oils (a) Australian, (b) American and (c) Iranian.
Figure 7.
Changes in the fatty acid profile (palmitic, palmitoleic, stearic, oleic, and linoleic acid) of Australian, American, and Iranian almonds during forced oxidation at 60 °C.

Parameters	Samples Almond oil	Days of oxidation (60 °C)
Parameters	Samples Almond oil	0	3	6	9	12	15	18	21
FFA (%)	Australian	0.55 ± 0.02^h	0.65 ± 0.03^g	0.95 ± 0.04^f	1.07 ± 0.04^e	1.21 ± 0.05^d	1.93 ± 0.08^c	2.42 ± 0.09^b	2.76 ± 0.11^a
	American	0.48 ± 0.02^h	0.61 ± 0.03^g	0.89 ± 0.04^f	0.98 ± 0.05^e	1.08 ± 0.04^d	1.88 ± 0.05^c	2.32 ± 0.07^b	2.66 ± 0.08^a
	Iranian	0.44 ± 0.02^h	0.56 ± 0.03^g	0.67 ± 0.03^f	0.88 ± 0.04^e	1.02 ± 0.05^d	1.77 ± 0.08^c	2.28 ± 0.09^b	2.58 ± 0.10^a
PV (meq·kg⁻¹)	Australian	2.66 ± 0.12^h	4.22 ± 0.16^g	5.75 ± 0.24^e	9.02 ± 0.37^a	8.05 ± 0.36^b	7.09 ± 0.25^c	6.03 ± 0.21^d	5.25 ± 0.17^f
	American	2.55 ± 0.11^h	4.08 ± 0.17^g	5.03 ± 0.21^e	8.06 ± 0.31^a	7.19 ± 0.29^b	6.87 ± 0.21^c	5.06 ± 0.23^d	4.88 ± 0.15^f
	Iranian	2.95 ± 0.13^h	4.93 ± 0.19^g	6.02 ± 0.26^e	9.88 ± 0.36^a	8.87 ± 0.35^b	7.65 ± 0.27^c	6.43 ± 0.28^d	5.41 ± 0.17^f
p-anisidine (p-AV)	Australian	3.67 ± 0.13^h	5.03 ± 0.19^g	7.06 ± 0.31^f	9.89 ± 0.34^e	10.88 ± 0.39^d	12.71 ± 0.42^c	14.33 ± 0.61^b	16.88 ± 0.71^a
	American	3.71 ± 0.14^h	5.13 ± 0.21^g	7.24 ± 0.31^f	8.97 ± 0.32^e	10.44 ± 0.28^d	12.93 ± 0.31^c	14.02 ± 0.59^b	16.43 ± 0.66^a
	Iranian	3.63 ± 0.12^h	5.18 ± 0.22^g	6.45 ± 0.27^f	8.23 ± 0.31^e	10.02 ± 0.42^d	12.44 ± 0.47^c	14.21 ± 0.35^b	15.89 ± 0.44^a
TOTOX	Australian	8.99 ± 0.27^h	13.47 ± 0.51^g	18.56 ± 0.76^f	27.93 ± 0.91^a	26.98 ± 1.28^c	26.89 ± 1.03^d	26.39 ± 1.06^e	27.38 ± 1.14^b
	American	8.81 ± 0.31^h	13.29 ± 0.44^g	17.30 ± 0.62^f	25.09 ± 0.89^c	24.82 ± 0.95^d	26.67 ± 1.31^a	24.14 ± 1.02^e	26.19 ± 1.07^b
	Iranian	9.53 ± 0.25^h	15.04 ± 0.54^g	18.49 ± 0.72^f	27.99 ± 0.94^a	27.94 ± 1.02^b	27.74 ± 1.16^c	27.07 ± 1.04^d	26.71 ± 0.98^e
The values provided in the table are the mean values of triplicate analysis with standard deviation. Means followed by different superscripts in the same column differ significantly (Tukey's test at 0.05 p-level the population are significantly different).

Table 1.

Comparative results of (FFA, PV, p-AV, TOTOX) during 21 d forced oxidation of kernels oil (almond).

Samples	Fatty acids	Days of oxidation (60 °C)
Samples	Fatty acids	0	3	6	9	12	15	18	21
Australian almond oil	C16:0	5.306 ± 0.21^b	5.000 ± 0.19^h	5.160 ± 0.21^f	4.860 ± 0.19^a	5.277 ± 0.23^c	5.161 ± 0.18^e	5.140 ± 0.22^g	5.220 ± 0.23^d
	C16:1	0.269 ± 0.01^b	0.210 ± 0.01^g	0.290 ± 0.02^a	0.200 ± 0.01^h	0.212 ± 0.02^f	0.240 ± 0.02^d	0.230 ± 0.02^e	0.241 ± 0.02^c
	C18:0	2.152 ± 0.09^a	2.010 ± 0.08^g	2.100 ± 0.06^b	2.080 ± 0.06^d	2.099 ± 0.05^c	2.070 ± 0.06^e	2.050 ± 0.05^f	2.000 ± 0.05^h
	C18:1	72.765 ± 2.76^h	74.020 ± 3.23^f	73.940 ± 2.84^g	74.473 ± 3.03^e	74.985 ± 3.14^a	74.750 ± 3.19^b	74.690 ± 2.96^c	74.620 ± 3.02^d
	C18:2	19.508 ± 0.68^a	18.760 ± 0.67^b	18.510 ± 0.56^c	18.388 ± 0.61^d	17.426 ± 0.56^h	17.780 ± 0.55^g	17.890 ± 0.51^g	17.920 ± 0.54^e
American almond oil	C16:0	5.223 ± 0.21^g	5.480 ± 0.23^e	5.501 ± 0.24^c	5.419 ± 0.20^d	5.569 ± 0.21^a	5.509 ± 0.20^b	5.080 ± 0.18^h	5.320 ± 0.19^f
	C16:1	0.256 ± 0.01^d	0.251 ± 0.02^e	0.260 ± 0.02^c	0.210 ± 0.01^h	0.230 ± 0.02^g	0.280 ± 0.02^a	0.270 ± 0.02^b	0.250 ± 0.01^f
	C18:0	1.894 ± 0.05^a	1.490 ± 0.05^f	1.480 ± 0.05^g	1.640 ± 0.07^c	1.530 ± 0.07^d	1.400 ± 0.06^h	1.710 ± 0.08^b	1.520 ± 0.07^e
	C18:1	74.775 ± 2.62^g	74.690 ± 2.83^h	75.138 ± 3.12^f	75.142 ± 3.05^e	75.532 ± 2.91^b	75.312 ± 3.23^d	75.480 ± 3.04^c	75.730 ± 3.12^a
	C18:2	17.852 ± 0.69^b	18.090 ± 0.71^a	17.622 ± 0.68^c	17.588 ± 0.59^d	17.138 ± 0.57^h	17.498 ± 0.48^e	17.460 ± 0.60^f	17.180 ± 0.59^g
Iranian almond oil	C16:0	5.181 ± 0.19^g	5.130 ± 0.23^h	5.510 ± 0.23^b	5.331 ± 0.21^e	5.309 ± 0.20^f	5.470 ± 0.24^c	5.531 ± 0.25^a	5.349 ± 0.22^d
	C16:1	0.240 ± 0.01^f	0.280 ± 0.02^c	0.290 ± 0.02^b	0.260 ± 0.01^e	0.261 ± 0.01^d	0.220 ± 0.01^g	0.291 ± 0.02^a	0.210 ± 0.02^h
	C18:0	2.074 ± 0.08^a	1.860 ± 0.12^d	1.710 ± 0.11^g	1.880 ± 0.09^c	1.760 ± 0.09^f	1.820 ± 0.08^e	1.660 ± 0.07^h	1.950 ± 0.11^b
	C18:1	74.891 ± 3.01^h	76.670 ± 3.42g	77.050 ± 3.55^f	77.218 ± 3.61^e	77.322 ± 3.53^c	77.410 ± 3.46^b	77.248 ± 3.08^d	78.082 ± 3.14^a
	C18:2	17.614 ± 0.59^a	16.060 ± 0.48b	15.440 ± 0.46^c	15.312 ± 0.47^e	15.348 ± 0.39^d	15.080 ± 0.41^f	15.272 ± 0.51^g	14.409 ± 0.38^h
The values provided in the table are the mean values of triplicate analysis with standard deviation. Means followed by different superscripts in the same column differ significantly (Tukey’s test at 0.05 p-Level the population are significantly different).

Table 2.

Fatty acid composition of (Australian, American and Iranian) almond kernel oil during forced oxidation of 21 d.