Fermentation of Chortan (heated strained yoghurt) by Lactobacillus helveticus : sonication treatment and biological activities

Summary In the present study, the effects of continuous and pulsed ultrasound (100 W, 30 kHz, 25–75% amplitudes for 30 min) and fermentation process (37°C for 24 h) by Lactobacillus helveticus PTCC 1332 on biological activities of Chortan were investigated. The obtained results showed that fermentation enhanced protease content (36.27% (neutral), 37.57% (acid), 39.28% (alkaline) protease), peptide concentration (45.27%) and antioxidant activity...