Investigation of the antioxidation capacity of gallic acid and its alkyl esters with different chain lengths for dried oyster during ambient storage

Summary The antioxidant capacity of gallic acid (GA) and its fatty alkyl esters such as butyl gallate, octyl gallate (OG), lauryl gallate and hexadecyl gallate in freeze-dried oyster was investigated. During ambient storage, the significant increase of peroxide value and thiobarbituric acid value together with the decline for docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents indicated the occurrence of lipid autoxidation in freeze-dried oysters. Meanwhile, the oxidative degradation of glycerol phosphocholine (GPC), glycerol phosphoethanolamine (GPE) and triacylglycerols (TAG) molecular species carrying DHA or EPA in oyster ranked as: TAG > GPE > GPC. GA and its alkyl esters could effectively be prevented dried oyster lipid from oxidation. Among them, OG stood out as the most effective individual. This work implied that the chain lengths of GA alkyl esters affect their antioxidant ability for dried oysters, which provides the information for selecting eligible antioxidants to enhance the oxidative stability of freeze-dried seafood.