Microencapsulation of Lactobacillus rhamnosus with fructooligosaccharide biopolymeric system in mozzarella cheese

Abstract

The present study was designed for extraction of fructooligosaccharides (FOS) from banana peel to encapsulate L. rhamnosus and its utilization in development of probiotics mozzarella cheese. FOS was quantified and characterized for its prebiotic properties. L. rhamnosus strains were isolated and characterized for probiotic properties. L. rhamnosus RHA8 was selected for encapsulation due to its better probiotic potential. FOS and sodium alginate (SA) were used for encapsulation of L. rhamnosus RHA8 with five different formulations Mo) SA100%, M1) SA 75% + FOS 25%, M2) SA 50% + FOS 50%, M3) SA 25% + FOS 75% and M4) FOS 100%. The stability of free and encapsulated L. rhamnosus was assessed in bile salt solution, simulated gastric juice, release in simulated intestinal fluid and storage stability. All the treatments provided better encapsulation efficiency except M4. Microencapsulation significantly maintained the viability of L. rhamnosus in simulated gastric conditions, bile salt, low pH and during storage. M2 was considered as best encapsulation treatment for survival of L. rhamnosus. The scanning electron microscopy revealed that alginate beads have pores but addition of FOS improved the structure of beads. M2 beads revealed less pores and better spherical shape. FTIR results confirmed the presence of FOS and sodium alginate in their respective treatments. In simulated gastric juice, the viability was maximum (8.49±0.07) with increased concentration of fructooligosaccharides up to treatment M2. However, maximum release was observed for M3 (100±0.5%) and minimum for Mo (95±1.0%). Probiotic mozzarella cheese was prepared with free and encapsulated L. rhamnosus with different formulations. The physicochemical analysis of cheese during storage demonstrated that moisture, fat, protein, ash, lactose and pH exhibited decreasing trend, while total solids and titratable acidity depicted increasing trend. The results of microbial analysis during storage exhibited increasing trend for total plate count and probiotic count. Similarly, lactic and acetic acid production was found higher during storage. The rheological and textural analysis showed increasing trend for meltability, flowability, stretchability and hardness. The decreasing trend was observed for chewiness and gumminess during storage. The sensory evaluation revealed that probiotic mozzarella cheese M4 was assigned highest scores by the panellists during storage. The results concluded that FOS can be extracted from the banana peel waste and successfully used as prebiotic based encapsulation material for effective delivery of L. rhamnosus in food systems. The variation in combination of wall materials provided opportunity to develop encapsulation beads with better structure and protection. The research will provide base for the development of indigenous probiotics to stakeholders e.g. pharmaceutical and food industries in Pakistan.