Abstract Jucara palm tree is considered an important species in the Atlantic forest ecosystem and the exploitation of its fruits is a main sustainable strategy adopted to its maintenance. Among several microorganisms in the jucara fruits, were found lactic acid bacteria (LAB) highly capable of synthesizing exopolysaccharides (EPS). Thus, the EPS synthesized by Leuconostoc pseudomesenteroides JF17 was characterized according to its chemical structure, physicochemical properties and antioxidant activity. HPLC analysis showed that the EPS consisted of a homopolysaccharide composed of glucose units, FT-IR spectroscopy revealed a dextran, confirmed by 1H and 13C NMR spectra which showed the composition of the polysaccharide, d -glucose units bound by α-(1→6). The EPS showed high water retention capacity, 507.812 ± 47.471 %, and may be related to the porous structure revealed by SEM images. Thermal analysis indicated that the EPS had excellent thermal stability with degradation temperature of 320.8 °C and melting point at 279.81 °C, with the enthalpy of 106.557 J/g. The EPS also presented sequestration ability on different free radicals tested, indicating high antioxidant activity. The results suggest that L. pseudomesenteroides JF17 might be widely used in the production of dextran which has potential qualities for applications in the food industry.

中文翻译：

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由 juçara 果实 (Euterpe edulis Martius) 中的 Leuconostoc pseudomesenteroides JF17 产生的胞外多糖的表征和抗氧化活性

摘要 Jucara 棕榈树被认为是大西洋森林生态系统中的重要物种，其果实的开发是其维持的主要可持续策略。在 Jucara 果实中的几种微生物中，发现了具有高度合成胞外多糖 (EPS) 能力的乳酸菌 (LAB)。因此，由 Leuconostoc pseudomesenteroides JF17 合成的 EPS 根据其化学结构、理化性质和抗氧化活性进行表征。HPLC 分析表明 EPS 由葡萄糖单元组成的同多糖组成，FT-IR 光谱显示葡聚糖，通过 1H 和 13C NMR 光谱证实多糖的组成，d-葡萄糖单元由 α-(1→6 ）。EPS 显示出高保水能力，507.812 ± 47.471 %，并且可能与 SEM 图像显示的多孔结构有关。热分析表明EPS具有优异的热稳定性，降解温度为320.8°C，熔点为279.81°C，焓为106.557 J/g。EPS 还表现出对不同自由基的螯合能力，表明具有高抗氧化活性。结果表明 L.pseudomesenteroides JF17 可广泛用于生产葡聚糖，其在食品工业中具有潜在的应用价值。表明高抗氧化活性。结果表明 L.pseudomesenteroides JF17 可广泛用于生产葡聚糖，其在食品工业中具有潜在的应用价值。表明高抗氧化活性。结果表明 L.pseudomesenteroides JF17 可广泛用于生产葡聚糖，其在食品工业中具有潜在的应用价值。