Do different chain lengths and configurations of gallate affect its antioxidant activity?

Abstract 10 gallic acid (GA) esters antioxidants with different ester group structures were prepared and characterized. The antioxidant effects of these antioxidants were evaluated under accelerated storage conditions and compared with commercial antioxidants. The results showed that the antioxidant effects of octyl gallate with 3 different configurations were superior to those of butylhydroquinone (TBHQ) and GA, but there was no significant difference in the antioxidant effects of these 3 configurations. In addition, FT-IR, 1H NMR, and 13C NMR showed that omega-3 unsaturated fatty acids were the first to be oxidized. Docosahexaenoic acid is more distributed in the sn-2 position, while eicosapentaenoic acid is more distributed in the sn-1,3 region, and fatty acids located at sn-2 were the least resistant to thermal oxidation. This study provides basic data for selecting suitable antioxidants to improve the oxidative stability of fish oil during storage, and also provides design rules and techniques on how to develop new and efficient antioxidants.