Abstract:In order to develop safe and food-derived angiotensin converting enzyme (ACE) inhibitory peptides, the scallop skirt was fermented by Bacillus natto. The single factor test was used to determine the fermentation paremeters such as fermentation time, fermentation temperature, inoculum size and liquid-to-material ratio with the peptide content and ACE inhibition rate as indicators. Box-Behnken response surface analysis was applied to optimize the process conditions and a quadratic multiple mathematical model was established. The results showed that the regression model could better reflect the relationship between the level of each factor and the response value, the order of factors affecting peptide content was time > liquid-to-feed ratio > inoculation amount > temperature, the influence of each factor on ACE inhibition rate was time > liquid-to-feed ratio > inoculation amount > temperature. The best technological conditions for the preparation of ACE-inhibitory peptide from natto fermented product were as follows: fermentation time 38.4 h, fermentation temperature 39.9 ℃, inoculation amount 6.0%, liquid to material ratio 22.5. Under the fermentation conditions above, the polypeptide content was 238.91 mg/g in the lyophilized product, in which the ACE inhibition rate was up to 83.70%. The results of this study provide a theoretical basis for the high-valued application of scallop skirt and development of food-derived ACE inhibitory peptides.
