Improved peptide generation from milk fermented by heat-shocked Lactobacillus helveticus

Summary High macromolecular protein content in bovine milk produces a firm and dense coagulum in the stomach. To increase the number of easily digested peptides, we were the first to introduce heat-shocked Lactobacillus helveticus to fermented milk. The results showed that acid production was inhibited significantly (P < 0.01) over 14 h of fermentation; the content of small peptides and nonapeptide increased 28.03% and 27.78%, respectively, including three specific and fifteen common bioactivity peptides. The identified type of peptides from α-casein, β-casein and κ-casein increased by 12.05%, 30.73% and 19.30%, respectively, and the distribution of peptides was similar to intestinal digestion. Therefore, this attenuated strain could improve the generation of small molecular peptides and bioactive peptides to promote the degradation of proteins and accelerate milk protein digestion and absorption. This approach might be used to develop functional dairy products.