Structural characteristics of low bitter and high umami protein hydrolysates prepared from bovine muscle and porcine plasma.

The aim of this study was to use different enzyme mixtures to investigate the influence of peptide characteristics and taste of protein hydrolysates from bovine muscle and porcine plasma. Minced beef and porcine plasma were hydrolysed using 10 food-grade enzymes, including Protease A, Protease P, ProteAX, Flavourzyme, Alcalase, Papain, Bromelain, Protamex, Neutrase and Sumizyme BNP-L. The relationship between degree of hydrolysis (DH), molecular weight (MW) distribution, enzyme specificity, and sensory characteristics of hydrolysates were investigated. The results demonstrated that Protease A, a mixture of endo- and exo-peptidases, was the optimal protease to generate hydrolysates with low bitterness. Endopeptidases (Papain and Bromelain) elicited bitter taste of protein hydrolysates. A positive correlation was suggested between umami taste and MW distribution (<0.5 kDa), while bitterness was positively correlated with MW distribution (0.5-1 kDa). Overall, hydrolysis with enzyme preparations containing endo- and exo-peptidases was effective to reduce bitterness of hydrolysates.