Color and flavor of flaxseed protein hydrolysates Maillard reaction products: effect of cysteine, initial pH, and thermal treatment

The effects of cysteine, initial pH, and thermal treatment on the color and flavor derived from Maillard reaction of flaxseed protein hydrolysates were investigated. Browning and color of Maillard reaction products (MRPs) were inhibited at higher cysteine concentration and lower initial pH. Higher cysteine or initial pH suppressed the cross-linking of 128-1,000 Da peptides and accelerated the degradation of peptides with a higher molecular weight (MW) (>1,000 Da). The higher temperature and longer reaction time resulted into a marked increase in flavor formation in the Maillard reaction model. Partial least squares regression (PLSR) revealed that volatile compounds, MW distribution, and amino acids of MRPs had a significant influence on MRPs sensory characteristics. The generation of umami, mouthfulness, and continuity was observed at relatively lower temperatures and longer heating time. The sulfur- and nitrogen-containing compounds from the low MW peptides (<1,000 Da) may lead to meaty aroma in MRPs.