Optimization of Antihypertensive Peptide Preparation by Lactobacillus plantarum Fermentation of Soy Whey

Abstract

To optimize the process conditions of preparation of antihypertensive peptides from the soybean whey fermented by Lactobacillus plantarum, based on the single factor, the response surface method was used and its antihypertensive activity in vitro was studied. The results of variance analysis showed that the order affecting the polypeptide yield was: the initial pH > fermentation time > fermentation temperature > glucose addition. The model regression analysis showed that the optimal conditions for the production of antihypertensive peptides by Lactobacillus plantarum were as follows: fermentation temperature was 37 °C, fermentation time was 17 h, the initial pH of fermentation was 6.4, the amount of glucose addition was 1.50%, the polypeptide yield was 62.53% and the predicted value was 61.61%, with no significant difference (P > 0.05). In vitro, antihypertensive activity results showed that the angiotensin-converting enzyme (ACE) inhibition rate of fermented soy whey peptides was 85.77%. The results provided the theoretical basis for the high-value development and utilization of soy whey.