Sustainable bacterial cellulose-based delivery system for probiotic stabilization in functional beverages

Abstract The growing demand for functional foods has driven innovation in probiotic delivery systems that ensure microbial stability and targeted release. Probiotics, defined as live microorganisms conferring health benefits, often face challenges related to survival during processing, storage, and gastrointestinal transit. This study investigates bacterial cellulose (BC), a biopolymer produced by acetic acid bacteria, as a natural and sustainable encapsulating material for improving the stability and delivery of Enterococcus faecalis RITBM S15-3 in a functional beverage. Freeze-dried BC was characterized by Fourier-transform infrared spectroscopy (FTIR), and probiotic cells were encapsulated within a pectin/BC composite matrix before incorporation into a mango-based functional beverage. The viability of encapsulated probiotics was assessed under simulated gastrointestinal conditions, during 16 days of ambient storage, and by monitoring beverage physicochemical properties and antioxidant activity. The viable cell count decreased from 9.25 to 8.18 log CFU/ml after exposure to simulated gastric fluid and further to 6.39 log CFU/ml following simulated intestinal conditions, demonstrating substantial protection of encapsulated cells during gastrointestinal transit. During storage, the beverage retained viable probiotic populations above the recommended therapeutic level while maintaining stable pH and enhanced bioactive properties. The functional beverage exhibited 61.11 mg GAE/100 g total phenolics, 69.63 mg RE/100 g total flavonoids, and 69.19 % DPPH radical scavenging activity, all higher than those of the control beverage. Overall, bacterial cellulose proves to be a promising encapsulation medium for probiotic delivery in functional beverages, advancing innovation in the functional food sector.