Abstract:

The goal of the present study was to develop a microbial fermentation method for producing milk-derived ACE inhibitory peptides using a strain of Lactobacillus helveticus TS6024 preserved in our laboratory. Based on the determination of the optimal fermentation substrate for production of ACE inhibitory peptides, the optimal fermentation parameters were investigated using one-factor-at-a-time method and central composite design combined with response surface analysis. Results showed that a mixture of skim milk powder and vegetable protein consisting of half volume of soybean protein isolate and half volume of peanut protein isolate with a ratio of 9:1 (V/V) was chosen as the optimal fermentation substrate. The optimal values of fermentation parameters were skim milk concentration 9.67% (m/V), substrate sterilization time 30 min, inoculation amount 3% (V/V), and fermentation temperature 38.82 ℃ for a fermentation period of 6.26 h. The ACE inhibitory peptides under such conditions revealed an ACE inhibitory activity of 92.26%.

Key words: Lactobacillus helveticus, ACE inhibitory peptide, response surface methodology