Enzymatic hydrolysis of flaxseed (Linum usitatissimum L.) protein and sensory characterization of Maillard reaction products.

We aimed to simplify the enzymolysis process for flaxseed protein hydrolysates production as Maillard reaction products (MRPs) to generate different flavor characteristics. More than 50% activity of immobilized enzymes (Alcalase and Flavourzyme) was retained after repeated use. Subsequently, after five weeks, the activities of the immobilized enzymes were also observed to be higher after storage at 4 °C. The optimum conditions for production of flaxseed protein hydrolysates using sequential enzymatic hydrolysis were as follow: 3,000 U/g of Alcalase at 60 °C and pH 8.0 for 2 h and 120 U/g of Flavourzyme at 50 °C and pH 6.5 for 2 h. Partial least squares regression analysis revealed that resulting peptides with the molecular weight (MW) higher than 1,000 Da could improve the mouthfulness and stability in umami soup; whereas, peptides with MW of 128-1,000 Da mainly contributed to the generation of meat-like flavor compounds with a significant effect on umami taste and bitterness.