Technofunctional properties of dextran produced by Leuconostoc pseudomesenteroides isolated from juçara palm fruit

Abstract

Juçara fruits (Euterpe edulis Martius), an important palm tree native to the Atlantic Forest ecosystem, exhibit a rich diversity of microorganisms, including lactic acid bacteria (LAB). LAB are highly capable of synthesizing exopolysaccharides (EPS), which are extracellular carbohydrate biopolymers with techno-functional properties, and consequently, wide applicability. In the present study, the technical-functional information of the dextran produced by L. pseudomesenteroides JF17 was obtained by determining its physicochemical, rheological, water-holding, oil-holding, and emulsifying properties. Dextran-JF17 mainly comprised carbohydrates (87.87% ± 1.45%, w/w), along with 48.86% ± 1.2% (w/w) of soluble fibers and a low protein content (2.98% ± 0.49%, w/w). The dextran exhibited high water-holding (470.89% ± 39.67%, w/v) and oil-holding (89.945% ± 4.16%, w/v) capacities, with values close to those reported for other microbial EPS. The dextran-JF17 solutions with concentrations 0.5%, 1.0%, and 2.0% (w/v) exhibited the typical pseudoplastic non-Newtonian fluid behavior. The emulsifying capacity of dextran-JF17 was higher (26.73 ± 0.31 mL of oil/g dextran) than that of guar gum (15.45 ± 1.33 mL oil/gum). In addition, dextran-JF17 presented an emulsifying activity of approximately 65% (w/v) within 24 h, indicating a strong emulsion stabilization capacity. Collectively, these results suggested that dextran-JF17 is a good candidate for application as a viscosity, stabilizing, and emulsifying agent in the food and pharmaceutical industries.