Investigation of physico-chemical and microbial properties of low fat yogurt enriched with whey protein concentration, milk protein concentration, and wheat-psyllium fiber

In this study, the effect of WPC, MPC, Milk powder, wheat fiber, and mixer of wheat and psyllium fiber at two levels (1 and 2%) on the physicochemical, quality properties of low-fat yogurt during 21-day storage time investigated. The results of this research showed that the addition of a mixer of wheat and psyllium fiber caused decreasing in pH and increasing in acidity. Samples contain MPC had the least Syneresis and the highest viscosity so that the difference among samples was significant. Samples contain WPC, had the most TSS. On the first day and 21st day, samples with WPC and milk powder had the most microbial growth, respectively. According to these results, the best effects on quality properties were included: decreasing Syneresis, increasing viscosity especially for MPC samples, and a good influence on microbial growth for all samples. Overall, using fibers and protein concentrate compounds can improve quality properties and has a good potential for application in varied food products.