Optimization and characterization of exopolysaccharides from Leuconostoc citreum BH10 and its functional properties in vitro

Abstract

Abstract In this study, the yield of exopolysacchrides (LCEPS) produced by Leuconostoc citreum BH10 was optimized through the improvement of fermentation conditions. A three-level four-factor central composite design coupled with response surface methodology was employed to elucidate the interactions among four design variables, namely fermentation time (X1), fermentation temperature (X2), sucrose concentration (X3), and inoculation amount (X4) over a broad range of process conditions and determine their effects on LCEPS production. Based on the developed models, under the optimum process conditions of 49.99 h, 25.59 °C, 21.66, and 3.00%, the obtained maximum production of LCEPS was up to 55.96 g/L. Besides, the produced LCEPS presented better thermal stability than the original dextran and rendered finely emulsifying properties compared with commercial emulsifiers. Moreover, the LCEPS possessed good antioxidant activities and showed certain biofilm inhibition against Staphylococcus aureus ATCC 6538 strain, which indicated that it has fine potential to be used as an excellent additive into the food industry. Graphical Abstract

Keywords

• Exopolysacchrides
• Leuconostoc citreum BH10
• Response surface methodology
• Emulsifying property
• Antibiofilm activities