EFFECT OF INTERMITTENT FRYING ON FATTY ACIDS, VITAMIN E, LIPID OXIDATION AND ACRYLAMIDE IN OILS AND PLANTAIN CHIPS COLLECTED FROM SMALL- SCALE PRODUCERS IN CAMEROON

Deep-fat frying is susceptible to induce the formation of undesirable products as lipid oxidation products and acrylamide in fried foods. Plantain chips produced by small-scale producers are sold to consumers without any control. The objective of this study was to evaluate the quality of plantain chips from local producers in relation to production process parameters and oils, and to identify the limiting factors for the production of acrylamide in plantain chips. Samples of frying oils and plantain chips prepared with either palm olein or soybean oil were collected from 10 producers in Yaoundé. Quality parameters determined in this study were: fatty acid composition of the oils, determined by gas chromatography (GC) of free acid methyl ester; trans fatty acids, determined by Fourier transform infra-red spectroscopy; Tocopherols and tocotrienols as markers of nutritional quality were analyzed by High Performance Liquid Chromatography in isocratic mode. Free fatty acids and acylglycerols as markers of lipid hydrolysis were analyzed by GC of trimethylsilyl derivatives of glycerides. Conjugated dienes, Anisidine value and viscosity as markers of lipid oxidation and thermal decomposition of the oils; acrylamide which is formed through Maillard reaction and identified as a toxic compound in various fried products. Asparagine content of the raw fresh plantain powder was also determined. Fatty acid composition of palm oleins was stable within a day of intermittent frying. In soybean oils, about 57% and 62.5% of linoleic and linolenic acids were lost but trans fatty acids were not detected. Soybean oils were partly hydrolysed leading to the formation of free fatty acids, monoacylglycerols and diacylglycerols. In both oils, tocopherols and tocotrienols contents decreased significantly by about 50%. Anisidine value (AV) and polymers contents increased slightly in fried palm oleins while conjugated hydroperoxides, AV and polymers greatly increased in soybean oils. Acrylamide was not detected in the chips. This is explained by the absence of asparagine in the raw plantains, the other acrylamide precursors being present. This study shows that the plantain chips prepared at the small-scale level in Yaounde with palm olein are of good quality regarding oxidation and hydrolysis parameters and the absence of acrylamide. In contrast, oxidation developed with soybean oil whose usage for frying should be questioned. Considering that asparagine is the limiting factor for the formation of acrylamide in plantain chips, its content depending on several factors such as production parameters and maturity stage should be explored.

Determination of acrylamide levels in selected commercial and traditional foods in Syria

Purpose: To determine acrylamide (AA) levels in different brands of commercial and traditional foodstuffs available in Syria by ultra-performance liquid chromatography-mass spectrometery (UPLCMS). Methods: A total of 63 samples were analyzed. Food samples were defatted by hexane and then extracted with methanol 98 % in a vortex mixer. Thereafter, Carrez I and Carrez II were added to precipitate proteins from the co-extractives and then centrifuged to obtain a clear aqueous extract that was evaporated to dryness. The extract was dissolved in 1 mL of water, eluted through a preconditioned Oasis HLB cartridge and then filtered. The filtrate was analyzed by UPLC-MS/MS to determine AA content. Results: Among the commercial foods tested, the highest acrylamide quantity was found in potato products (396 ± 3.59 – 1844 ± 5.29 μg kg−1) and the lowest in corn products (183 ± 2.64 – 366 ± 4.58 μg kg−1). This was followed by biscuits (57 ± 2.64 – 1433 ± 2.51 μg kg−1), breakfast cereals (121 ± 8.73 – 245 ± 3.60 μg kg−1), bread (119 ± 1.73 – 263 ± 3.60 μg kg−1) and then coffee (113 ± 2.64 - 64 ± 3.05 μg kg−1). Regarding traditional foods, the highest level of AA was found in AL- Mshabak (481 ± 2.08 μg kg−1) and AL-Awamat (421 ± 2.64 μg kg−1) followed by AL-Namora (282 ± 4.35 μg kg−1) and AL-Kenafa (242 ± 2.64 μg kg−1). It was also observed that the lowest amount of AA was in fried bread (230 μg kg−1), AL-Fatayer (192 ± 3.51 μg kg−1) and AL-Baqlawa (172 ± 4.35 μg kg−1) while Eid Aqras (130 ± 4.58 μg kg−1) and AL-Brazeq (167 ± 3.78 μg kg−1) contained the least amount of AA. Conclusion: The results indicate that the highest levels of AA are found in the most commonly consumed foods. There was significant difference (p < 0.05) in AA levels among different food items and within different brands of the same product.