Comparative survival of exopolysaccharide encapsulated Lactobacillus plantarum and Pediococcus pentosaceus in simulated gastrointenstinal conditions and storage time

Abstract

The objective of the present study was to evaluate the effect of microbial exopolysaccharide (EPS) encapsulation of lactic acid bacteria on enhancing their viability during exposure to the simulated conditions of the gasterointestinal tract. Lactobacillus plantarum (NR_104573.1) and Pediococcus pentosaceus (NR_042058.1) isolated from wheat bran sourdough were encapsulated by spray-drying with various ratios of EPS, whey protein concentrate, carboxymethyl cellulose and pectin. The viability, kinetics and survival under stress conditions were compared between the samples after 120 min of incubation and over 28 days of storage. HPLC was used for compositional assessment in terms of monosaccharide constituents, revealing that glucose, arabinose and xylose were the major components of the EPS produced by L. plantarum and P. pentosaceus. ANOVA demonstrated a significantly reduced logarithmic cycle of bacterial population in the control samples and free cells compared to the encapsulated L. plantarum and P. pentosaceus after 2 h in simulated gastric fluid conditions and bile salt solution. Encapsulation yields in the presence of WPC, CMC and pectin with and without EPS were about 85 and 80% for L. plantarum, and it was 81 and 75% for P. pentosaceus, respectively. Also, the viability number of L. plantarum and P. pentosaceus free cells decreased over 28 days of storage from 12.41 to 7.28 and 12.11 to 6.96 log Cfu/mL, respectively. Finally, by assessing the kinetics of the bacteria with three mathematical models, the Ritger–Peppas kinetics model was found to be a suitable correlation model for the data.