Comparison of the effectiveness of two prebiotics inulin and green banana flour on the survival of Lactobacillus plantarum and Bacillus coagulans in low-calorie synbiotic yogurt

Today, yogurt is produced as the most important probiotic dairy product worldwide and marketed. The combination of prebiotics with probiotics is called synbiotics, which have more beneficial effects on host health. This study was performed to compare the effect of inulin and green banana flour on the properties of synbiotic yogurt during 28 days of refrigerated storage. Inulin and green banana flour were used at 2% levels in synbiotic yogurt containing Lactobacillus plantarum and Bacillus coagulans and compared with control (probiotic) yogurt. The results showed that with increasing storage time, the acidity of all treatments increased and the pH value decreased. Addition of inulin and green banana flour increased the acidity and decreased the pH in the synbiotic samples, but no significant difference was observed between the two prebiotics used. Dry matter content in synbiotic treatments was significantly higher than control treatments (P <0.05).The presence of both prebiotic compound had a positive effect on the survival capability of probiotic bacteria in yogurt. The effect of inulin on the survival of Lactobacillus plantarum was greater than of green banana flour, but in treatment of Bacillus coagulans there was no significant difference between the two prebiotics. Count of Lactobacillus plantarum and Bacillus coagulans was higher than the recommended limit of 6 Log cfu /g in all samples of synbiotic yogurt during storage for 4 weeks. Survival of Bacillus coagulans were higher than Lactobacillus plantarum. According to the results of this study, it can be said that green banana flour has pre-biotic properties and is effective in maintaining the survival of probiotic bacteria, so it can be concluded that this combination has a high potential for use in healthy foods.