ε-聚赖氨酸-葡聚糖复合物的功能性研究

Functional Characteristics of ε-Polylysine-Dextran Complex

通过美拉德干热反应,利用羰基对蛋白质氨基进行改性,制备ε-聚赖氨酸-葡聚糖(ε-PL-DE)复合物,在提高其乳化性的同时,通过最小抑菌质量浓度法和牛津杯法对其抑菌性进行研究。结果表明:ε-PL-DE复合物在温度60℃时可较好保留ε-聚赖氨酸的抑菌性,随着反应温度提高,其抑菌性降低;且ε-PL-DE复合物抑菌性在中性和微碱性条件下较强,pH4、9的条件下较弱。通过SDS-PAGE、糠醛和色差的测定,证实ε-聚赖氨酸(ε-PL)和葡聚搪(DE)的美拉德反应不仅逐渐生成大分子物质,向终反应阶段过渡,褐变程度加深且不同温度下的美拉德反应程度也不同,高温反应会快于低温反应。

A ε-polylysine-dextran （ε-PL-DE） complex with enhanced emulsifying capacity was prepared by modifying amino groups with carbonyl groups through Maillard reaction. Its antibacterial activity was evaluated by minimum inhibitory concentration and Oxford cup methods. The results showed that the ε-PL-DE complex at 60 ℃ could keep the antibacterial activity of ε-PL well. However, the higher the temperature, the faster its antibacterial activity declined. The complex was stable to neutral or slightly alkaline conditions rather than pH 4 or 9. SDS-PAGE analysis and determination of furfural content and color difference demonstrated that the Maillard reaction between ε-PL and DE gradually produced macromolecules and entered the final reaction stage, aggravating browning. Meanwhile, the Maillard reaction proceeded faster at high temperatures.