Effect of incorporating orange fiber and mango juice on survival of Lactobacillus Casei, physicochemical and sensory properties of synbiotic apple juice

Growing public awareness about diet-related health issues has significantly led to a progressive demand for producing functional foods based on probiotics. Accordingly, this study aimed to investigate the feasibility of producing synbiotic apple juice containing Lactobacillus casei (L. casei) as a probiotic bacteria and mango juice (0 and 10% v/v) and orange fiber (0 and 0.5% w/v) as prebiotic agents. In this regard, the viability of L. casei, pH, acidity, total soluble solids, viscosity, and sensory properties of the samples were assessed during 45 days of storage at the refrigerated condition. According to the obtained results, incorporating orange fiber and mango juice as prebiotic compounds could significantly improve the viability of L. casei and maintain its survival above the minimum recommended value (7 Log CFU/mL) during the storage time. Furthermore, the addition of orange fiber and mango juice had a significant effect (p<0.05) on elevating the acidity, soluble solids, and viscosity as well as decreasing the pH value of the synbiotic apple juice samples during the storage time. Although sensory scores of the treatments showed a decreasing trend over time, the addition of mango juice and orange fiber could remarkably improve the overall acceptability of the treated samples compared to the control sample. In general, the results of this study showed that synbiotic apple juice containing orange fiber and mango juice in combination provided the best viability of L. casei with acceptable physicochemical and sensory properties and could be introduced as a synbiotic apple juice.