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

Abstract

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.