Antioxidant properties of lipid concomitants in edible oils: A review.

Edible oils are indispensable for human life, providing energy and necessary fatty acids. Nevertheless, they are vulnerable to oxidation via a number of different mechanisms. Essential nutrients deteriorate as well as toxic substances are produced when edible oils are oxidized; thus, they should be retarded wherever possible. Lipid concomitants have a strong antioxidant capacity and are a large class of biologically active chemical substances in edible oils. They have shown remarkable antioxidant properties and were documented to improve the quality of edible oils in varied ways. An overview of the antioxidant properties of the polar, non-polar, and amphiphilic lipid concomitants present in edible oils is provided in this review. Interactions among various lipid concomitants and the probable mechanisms are also elucidated. This review may provide a theoretical basis and practical reference for food industry practitioners and researchers to understand the underlying cause of variations in the quality of edible oils.

Synthesized alkyl ferulates with different chain lengths inhibited the formation of lipid oxidation products in soybean oil during deep frying.

The hydrophilic nature of ferulic acid limits its applications under lipophilic conditions. This study set out to evaluate the antioxidant efficacy of alkyl ferulates with different chain lengths in soybean oil under frying conditions. Ferulic acid was esterified with four unbranched fatty alcohols (C4:0-C16:0), and tert-butylhydroquinone (TBHQ) served as a standard for comparison. The antioxidant effect of alkyl ferulates increased with the alkyl chain length. The addition of antioxidants could inhibit increases in the levels of p-anisidine, total polar compounds, conjugated dienes, conjugated trienes, oxidized triglyceride monomers, triglyceride dimers, triglyceride oligomers, and glycerol core aldehydes efficiently, and the inhibitory effects of hexadecyl ferulate was the strongest. Moreover, hexadecyl ferulate and TBHQ exhibited better inhibitory effects on the generation of n-alkanals, (E)-2-alkenals, and 4-oxo-alkanals determined by 1H nuclear magnetic resonance than others. Hence, the long-chain alkyl ferulates meet the industrial demands for ideal antioxidants with strong antioxidant capacity at high temperatures.