Bioactive hydrolysates from casein: generation, identification, and in silico toxicity and allergenicity prediction of peptides.

Abstract

Bioactive casein peptides have attracted considerable attention for their applications in industry. However, there is little clarity regarding mass spectrometric profiles for peptides in enzymatic hydrolysates of casein produced under varying conditions. In this study, the compositions of the peptides from casein hydrolysates were compared for different enzyme/substrate ratio (E/S) and hydrolysis times. The toxicity, allergenicity and bioactivity of the identified peptides were assessed in silico. A total of 70 unique peptides were identified, and there were 28, 21, 13 and 8 peptides from αs1 -casein, αs2 -casein, β-casein and κ-casein respectively. The peptide number decreased with the increase in E/S and hydrolysis time. Moreover, peptides with relative molecular mass Mr ranging from 1000 to 1500 Da occupied the highest proportion of 31.43%, and almost all of the peptides showed Mr less than 5000 Da. In silico analysis showed that all of the peptides were non-toxic and non-allergenic, and several of them were assessed by PeptideRanker as having a relatively high likelihood of being bioactive peptides. Composition of the peptides in the casein hydrolysates varied with the enzymolysis conditions. This study's results may facilitate the production of target bioactive peptides by controlling E/S and hydrolysis time, which is beneficial for the application of casein peptides in the functional food industry. © 2017 Society of Chemical Industry.