Process optimization of Pediococcus pentosaceus 4412-derived exopolysaccharides as a prebiotic in banana pseudostem...

Exopolysaccharide (EPS)-producing Pediococcus pentosaceus 4412 exhibits remarkable health-promoting properties, making it a promising candidate for functional food production.

The production of EPS was statistically optimized using one-factor-at-a-time, Plackett-Burman, and response surface methodologies. CCD-based RSM optimized the prebiotic potential of EPS in the fermentation of banana pseudostem juice. The volatile organic compounds in fermented banana pseudostem juice (FBPJ) were analysed using GC-MS analysis. Further, the biological activity of FBPJ, including antimicrobial and antioxidant activity were assessed in vitro.

Primarily, EPS production was optimized using galactose (36.81 g/L), ammonium sulfate (2 g/L), and yeast extract (5 g/L), resulting in a 5.5-fold increase in yield (from the unoptimized baseline) to 3.46 ± 0.16 g/L. The prebiotic potential of EPS-4412 in the FBPJ was evaluated by monitoring viable probiotic cell counts, and the RSM optimized process resulted in a 3.67-fold increase in prebiotic activity. Viable cell counts were effectively maintained in the FBPJ17 sample compared with other samples after 30 days of storage at 4 °C. The pH and sugar contents decreased, whereas the total phenolic content (TPC) was elevated. The FBPJ17 exhibited significant antimicrobial activity against Salmonella enterica MTCC 1164 with a zone of inhibition of 15.7 ± 0.12 mm. The maximum DPPH and superoxide radical scavenging activities and reducing power of FBPJ17 were determined to be 74.43 ± 0.96%, 65.6 ± 1.1%, and 0.72 ± 0.058, respectively. In particular, EPS-4412 supported the growth of the lactic acid bacteria consortium (Lactiplantibacillus pentosus AKVIT2, Lpb. plantarum BFW MKVIT02, and P. pentosaceus 4412), which played a crucial role in the production of esters, ketones, and hydrocarbons, imparting fruity, floral, and citrus-like flavours. Hence, EPS-4412 could be considered as a prebiotic stimulant in industrial applications.