Characterization of lactic acid bacteria postbiotics: bioactive peptide on yogurt with thermal inactivation process

Abstract

Postbiotics are non-living microorganisms and/or their metabolites that offer health benefits to the host. The stability of postbiotics is maintained due to the inactive state of microorganisms, making them more resistant to environmental factors like temperature and oxygen. One of the promising metabolites acting as a postbiotic is peptides. Thermal process is one of the methods for obtaining postbiotics, influencing their physicochemical properties and quality. This study investigates the impact of thermal processes on bioactive peptide compounds and evaluates their potential health benefits in yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. Peptide sequences were analyzed before and after thermal inactivation, while health benefits were assessed in silico using the BIOPEP-UWM application. Results showed that thermal inactivation increases the diversity of bioactive peptides, particularly those with smaller molecular weights. Based on health benefit analysis, bioactive peptides with molecular weights <3 kDa from the thermal process predominantly have potential bioactivities as Angiotensin Converting Enzyme inhibitors and dipeptidyl peptidase IV inhibitors.