Functional Exploration of Encapsulated Probiotic Bacteria in Different Food Products

Abstract

The consumption of probiotic bacteria is continuously growing due to the numerous health benefits. Encapsulation is an effective approach for ensuring the target delivery of these probiotics. The present study was conducted in three phases. In first phase, encapsulation of probiotic bacteria (L. acidophilus) was done by encapsulator using sodium alginate and carrageenan as coating biomaterial. Obtained beads were characterized by optical, Scanning electron microscopy (SEM), X-ray diffraction (XRD) and FTIR. In second phase in vitro assay was carried out for selected functional properties. In third phase, a comparative study between free and encapsulated probiotics was done for accessing their viability and stability in carrier foods (yogurt and ice Cream). The products containing free and encapsulated probiotics were also subjected to physicochemical, microbiological and sensory characteristics. Microbeads, obtained from encapsulator were, smaller, predominantly spherical with smooth and rough surface and uniform in size. Additionally, FTIR analysis indicated an interaction between cell components and coating materials. The encapsulation yield for sodium alginate and carrageenan was 98 and 96 % respectively. Free/un-encapsulated cells exhibited poor survival under the simulated gastrointestinal conditions during their exposure to simulated gastric and intestinal juice as compared to encapsulated cells the viable count of encapsulated probiotic bacteria decreased from 9.92 log10 cfu to 8.75 log10 cfu and for free cells decreased from 9.94 log10 cfu to 5.46 log10 cfu in ice-cream over 120 days of storage. While for yogurt it decreased from 8.94 log10 cfu to 7.17 log10 cfu and for free cells decreased from 8.86 log10 cfu to 5.84 log10 cfu in yogurt over 28 days of storage. The results of the viable count in case of encapsulated cells were still above accepted level (106 cfu/g) that required for therapeutic benefits. The bacterial cells encapsulated in sodium alginate showed the highest survival rate in yogurt and ice cream after the storage period. Supplementation of free and Encapsulated probiotic bacteria in yogurt and ice cream significantly affected some of the physicochemical and sensorial parameters of both carrier foods. Yogurt supported considerably greater viability of probiotic as a food vehicle compared with ice cream. The results of present study demonstrated that encapsulation can significantly increase the survival rate of probiotic bacteria under simulated gastrointestinal conditions and in carrier foods (Ice cream and yogurt) over an extended period of shelf-life. This investigation indicated that encapsulation should be used as a potential delivery system for probiotics in food industry which is paving a new way for the development of functional foods.