The formation pattern of off-flavor compounds induced by water migration during the storage of sea cucumber peptide powders (SCPPs)

The formation pattern of off-flavor compounds induced by water migration in sea cucumber peptide powders (SCPPs) stored at 25 °C and 75% RH for 24 h and 80 days were investigated. Water migration characteristic of SCPPs was monitored by LF-NMR. The effect of water migration on structure and morphology were analyzed by SEM, CD, and FTIR, respectively. The antioxidant activity of SCPPs was detected by EPR. Volatiles generated from SCPPs were detected by P&T-GC-MS. The antioxidant activity of SCPPs declined and structure exhibited abnormalities during the storage. After 24 h of storage, kinds of aldehydes decreased and the content of alcohols increased obviously. After 80 days, (Z)-3,5-dimethyl-2-(1-propenyl)-pyrazine and 1,2-benzenedicarboxylic acid-bis(2-methylpropyl) ester were identified as the characteristic off-flavor. These off-flavor compounds were probably formed through Maillard reaction. esterification, and microbial metabolism. This study can provide a basis for further exploration of the off-flavor formation mechanism.