Development of chemical and sensory characteristics during enzymatic hydrolysis of soy

Enzymatically hydrolyzed vegetable protein was produced from soy protein us ing hydrolysis times of 0-20 h. The development of sensory properties and t he pattern of protein degradation was followed. Around two-thirds of the fi nal amount of free amino acids and degree of hydrolysis (DH) were achieved during the first 4 h of hydrolysis. Between 6 h and 10 h of hydrolysis the bouillon-like tastes increased significantly (P < 0.001). In this time inte rval the amount of free amino acids exceeded 40% of the total amino acids a nd the DH exceeded 50% of the theoretically possible (100%). Using partial least squares regression with standardisation of free amino acid data accor ding to their taste threshold values showed that free glutamic acid, aspart ic acid and lysine correlated with the bouillon-like tastes. By standardisa tion of free amino acid data with respect to their SD the specificity of th e enzymes for amino acid side-chains could be seen.