Encapsulation of Lactobacillus reuteri probiotic bacteria using soy protein isolate and whey protein isolate and inulin and Evaluation of its viability during storage and simulated gastrointestinal conditions

Because of the sensitivity of probiotic bacteria to storage conditions as well as to the specific digestive system, protection of the bacteria against these conditions seems necessary. The aim of this study was to investigate the effect of encapsulation by soy protein isolate, whey protein isolate and inulin on the viability of Lactobacillus reuteri in gastrointestinal condition and during storage. As can be seen from the results, the soy protein isolate-coated samples had higher moisture content than the whey protein-coated samples, and the addition of inulin reduced the moisture content of the samples. The results of water activity were also similar with the results of moisture content. The microscopic structure results show that the samples containing whey protein are more uniform. Survival results in the simulated gastric system indicate that the number of bacteria in the simulated gastric system decreases over time and the largest decrease occurred in the control sample. Between the microencapsulated samples, whey protein-encapsulated had the highest viability (86.3 %). Also, survival results in the simulated intestinal system show that the number of bacteria in the simulated intestinal system decreases during storage and the largest decrease occurred in the control sample, (un-coated sample). Among the encapsulated samples, the sample containing whey protein and inulin had the highest viability (88.75 %). As can be seen from the viability of the probiotic bacteria during the shelf life, the bacterial count decreased over time and the highest decrease occurred in the soybean protein isolate sample. Among the samples, the whey protein-coated sample with inulin had the highest viability.