Lipid degradation during salt-fermented antarctic krill paste processing and their relationship with lipase and phospholipase activities

Abstract

In this study, lipid degradation during the processing of salt-fermented Antarctic krill paste was studied by evaluating changes in physicochemical parameters, lipid content, and fatty acid composition, phospholipase (phospholipase A1 [PLA1], phospholipase A2 [PLA2], phospholipase C [PLC] and phospholipase D [PLD]) and lipase activities. Triacylglycerols (TAGs) were an important source of free fatty acids (FFAs) in Antarctic krill paste, causing an increase in FFA content in the early stage of processing, while phospholipids were intensely hydrolyzed during the mid-late stages. Lipase activities remained constant, while PLA2 and PLD activities increased during all stages of processing. The relative activities of PLA2 and PLC highly correlated with a decline in phosphatidylcholine (PC) and an increase in lysophosphatidylcholine (LPC). A high correlation was also observed between relative PLD activity and increased phosphatidic acid (PA). These results suggest that lipase, PLA2, and PLD contribute to the degradation of lipids during the processing of salt-fermented Antarctic krill paste.

Practical applications: Due to their abundance of Antarctic krill, fermentation technology can be applied to transform them into a popular condiment. The present study aimed to investigate changes in lipid composition throughout krill salt-fermentation, and to evaluate their potential effects on fermented krill product. Knowledge of lipase activities during processing is essential to improve the quality of the end products and to further elucidate the complicated mechanisms of lipid degradation.

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