Quality parameters, probiotic viability and sensory properties of probiotic stirred sesame yogurt

The beneficial effects of sesame seeds are of great interest for the conception of healthy dairy products such as probiotic stirred yogurt. We investigated the effects of adding raw or roasted sesame seeds on the probiotic viability, quality parameters and consumers acceptability of stirred yogurt during 28 days cold storage (4 °C). All yogurts were analyzed for microbial counts (starter culture and probiotic), pH, titratable acidity, proteolytic activity, syneresis and antioxidant activity. Yogurts containing sesame seeds showed the highest probiotic counts, proteolytic activity, radical scavenging activity high titratable acidity, and low pH. Raw and roasted sesame can selectively impact probiotic growth with limited effect on yogurt starter culture especially at long cold storage (14-28 days). Yogurts enriched with roasted sesame had higher sensory acceptability compared to control and probiotic yogurts. Roasted sesame can be successfully incorporated to improve probiotic viability and sensory properties of stirred yoghurt, as well as to improve the antioxidant properties.