Enhancing Bifidobacterium and lactic acid bacteria activity, and improving oxidative stability in functional algal concentrated yoghurt with Spirulina platensis powder

Abstract

The purpose of this study was to examine the growing demand for healthy functional dairy products by investigating the incorporation of Spirulina platensis into concentrated yoghurt and evaluating its impact on starter cultures and product properties. A comprehensive analysis demonstrated the potential of spirulina to enhance bifidobacteria growth, acidity, PUFA content, and antioxidant activity in yoghurts, indicating its potential to improve the nutritional quality and oxidative stability of dairy products. The study investigated the impact of different Spirulina ratios on the activity of yoghurt starter cultures, including Lb. casei, Lb. plantarum, Lb. acidophilus, and Bifidobacterium mix. Three concentrated yoghurt samples were prepared, including a control, a probiotic sample, and a sample incorporating Spirulina powder. The findings suggest that while Spirulina did not significantly affect lactic acid bacteria, it noticeably stimulated the growth of Bifidobacterium. Treated samples showed increased acidity and TVFAs, with pH values displaying an inverse trend compared to the control. Clear differences in colour parameters and sensory evaluations distinguished control from treated samples. Additionally, Spirulina supplementation demonstrated a pronounced effect in enhancing antioxidant activity, as observed through DPPH radical scavenging activity, and influencing the peroxide value, reflecting improved oxidative stability in the yoghurt. This successful utilisation of Spirulina suggests its potential application in diverse edible algae in the food sector, especially in dairy products, enhancing both nutritional and sensory aspects, as well as contributing to improved oxidative stability