Developing functional yogurt rich in bioactive peptides and gamma-aminobutyric acid related to cardiovascular health

This study aimed to develop a novel functional yogurt through improves the production of bioactive components that have biological functions. Yogurts were manufactured from skim milk fortified with whey protein concentrate (WPC) and were fermented with high viscosity yogurt starter as a single or mixed with highly proteolytic co-culture. In one treatment, trypsin was used to partially hydrolysis of milk before fermentation with mixed starter. Yogurts were investigated for viscosity, water-holding capacity (WHC), sensory attributes, proteolytic activity, γ-aminobutyric acid (GABA) content and biological activities. The fortification with WPC increased the viscosity and WHC, while addition of trypsin decreased the values of these properties. High proteolytic and biological activities were observed by addition of WPC and mixed starter whereas treatment with trypsin had greater effects. Yogurt treated with mixed starter and trypsin had the high content of GABA. Sensorial, all yogurt treatments were acceptable and the yogurt treated with highly proteolytic co-culture gained the highest score. The biological activities and GABA content of all yogurts increased after 14 days of cold storage. It is concluded that highly proteolytic starter and partial proteolysis could be used to produce functional yogurt enriched in bioactive peptides and GABA with cardiovascular health benefits for consumers.