Pilot-scale production of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 and its application in set yogurt

Abstract

Exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) is a linear dextran that is built by glucose units via α-1,6 glycosidic bond. The primary objective of this study was to investigate the yield of XG5 EPS and its application in set yogurt. In laboratory scale, the culture conditions of XG5 EPS production were optimized using the L9 (3 3 ) orthogonal test. Here, the optimized yield of XG5 EPS was 26.02 g/L under the conditions of 100 g/L sucrose, initial pH 7.0, 25°C incubation, and 100 rpm for 36 h in a shaking flask. Based on the optimized parameters of laboratory scale, a pilot fed-batch fermentation was performed in a 50-L bioreactor with an adjusted agitation speed of 20 rpm. The XG5 EPS yield reached 40.07 g/L in fedbatch fermentation, which was 54% higher than that achieved in laboratory scale. In addition, XG5 EPS was added into set yogurt to investigate its effect on the stability of set yogurt. Our data demonstrated that the XG5 EPS improved the water-holding capacity, texture profile, and viscosity of set yogurt during cold storage compared with the controls. In particular, addition of 0.5% XG5 EPS increased the structure of 3-dimensional network of set yogurt, which eventually improved the physical stability of the set yogurt. Overall, this study provided new insights for exploring the pilot scale production and application of dextran.

Levan Production by Suhomyces kilbournensis Using Sugarcane Molasses as a Carbon Source in Submerged Fermentation

“…A strong band of OH stretching was observed at 3249 cm −1 . The bands within the region of 3600–3200 cm −1 were due to OH vibration [ 58 ], and the band at 2924 cm −1 specifies CH bending. The region in the range of 3000–2800 cm −1 indicates the stretching vibration of CH and confirms the presence of fructose [ 22 ].…”

Storage stability of texture, organoleptic, and biological properties of goat milk yogurt fermented with probiotic bacteria

“…At the end of storage, the water holding capacity of goat yogurt with probiotic bacteria fluctuated around 53%, indicating that the gel network of probiotic yogurt was relatively dense and compact. This phenomenon could be associated with the secretion of exo-polysaccharide (EPS) by probiotic bacteria, which could interact with proteins in goat milk to enhance the hydration and water holding capacity of yogurt ( 38 ). It is worth noting that goat yogurt with L. acidi and L. casei had higher water holding capacity than those for tested yogurt with B. animalis and L. plantarum.…”

Maltose-Enhanced Exopolysaccharide Synthesis of Lactiplantibacillus plantarum through CRP-like Protein

“…32 In addition, during the manufacture of fermented milk and beverages, EPS reduces the amount of added milk solids required to improve the viscosity, texture, stability, and mouthfeel of the final product, thereby avoiding syneresis. EPS increased the viscosity of fermented milk, as described by Pan and Xu et al 33 The EPS of S. thermophilus strain S-3 increased viscosity, syneresis capacity, water holding capacity, and rheological properties of yogurt compared to Lactobacillus bulgaricus alone. L. plantarum 163, as a single strain, can be used to prepare yogurt with a viscosity higher than that of plain yogurt.…”