Formation and disappearance of aldehydes in fried clam during simulated gastrointestinal digestion
This study aimed at investigating the formation and disappearance of aldehydes during simulated gastrointestinal digestion (SD) of fried clam with high initial aldehyde concentrations. Results indicated that the SD with lipase initially reduced (at gastric stage), but subsequently increased (mainly at the intestinal stage) total aldehydes, especially eight specific aldehydes, including propanal, hexanal, acrolein, trans-2-pentenal, trans, trans-2,4-octadienal, trans, trans-2,4-decadienal, 4-hydroxy-nonenal and 4-hydroxy-hexenal. However, a similar SD process without lipase resulted in a time-dependent decrease in the total aldehydes and the eight aforementioned aldehydes. Meanwhile, SD (with lipase) of the fried clam significantly hydrolyzed triacylglycerol and polar lipids and generated free fatty acids (FFA); but the SD process without lipase caused negligible lipid hydrolysis. Thus, our results demonstrated a positive correlation between lipid hydrolysis and aldehyde generation during SD of fried clam due to the high oxidative susceptibility of FFA.