Zhang Ru-Yi, Wang Peng-Fei, Li Hua-Xiang, Yang Yan-Jun, Rao Sheng-Qi
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Polymers (Basel). 2023 Nov 24;15(23):4517. doi: 10.3390/polym15234517.
The aim of this investigation was to scrutinize the effects of a thermal treatment on the electrostatic complex formed between gum arabic (GA) and ε-polylysine (ε-PL), with the goal of improving the antibacterial properties and reducing the hygroscopicity of ε-PL. The heated complex with a ratio of 1:4 exhibited an encapsulation efficiency of 93.3%. Additionally, it had an average particle size of 350.3 nm, a polydispersity index of 0.255, and a zeta potential of 18.9 mV. The formation of the electrostatic complex between GA and ε-PL was confirmed through multispectral analysis, which demonstrated the participation of hydrogen bonding and hydrophobic and electrostatic interactions, as well as the enhanced effect of heat treatment on these forces within the complex. The complex displayed a core-shell structure, with a regular distribution and a shape that was approximately spherical, as observed in the transmission electron microscopy images. Additionally, the heated GA-ε-PL electrostatic composite exhibited favorable antibacterial effects on Salmonella enterica and Listeria monocytogenes, with reduced minimum inhibitory concentrations (15.6 μg/mL and 62.5 μg/mL, respectively) and minimum bactericidal concentrations (31.3 μg/mL and 156.3 μg/mL, respectively) compared to free ε-PL or the unheated electrostatic composite. Moreover, the moisture absorption of ε-PL reduced from 92.6% to 15.0% in just 48 h after being incorporated with GA and subsequently subjected to heat. This research showed a way to improve the antibacterial efficiency and antihygroscopicity of ε-PL, reducing its application limitations as an antimicrobial substance to some extent.
本研究的目的是仔细研究热处理对阿拉伯胶（GA）和ε-聚赖氨酸（ε-PL）之间形成的静电复合物的影响，以期提高ε-PL的抗菌性能并降低其吸湿性。比例为1:4的加热复合物的包封率为93.3%。此外，其平均粒径为350.3 nm，多分散指数为0.255，ζ电位为18.9 mV。通过多光谱分析证实了GA和ε-PL之间静电复合物的形成，这表明氢键、疏水和静电相互作用的参与，以及热处理对复合物中这些作用力的增强作用。如透射电子显微镜图像所示，该复合物呈现核壳结构，分布规则且形状近似球形。此外，加热后的GA-ε-PL静电复合物对肠炎沙门氏菌和单核细胞增生李斯特菌表现出良好的抗菌效果，与游离ε-PL或未加热的静电复合物相比，最低抑菌浓度（分别为15.6 μg/mL和62.5 μg/mL）和最低杀菌浓度（分别为31.3 μg/mL和156.3 μg/mL）降低。此外，与GA混合并随后加热后，ε-PL的吸湿率在短短48小时内从92.6%降至15.0%。本研究展示了一种提高ε-PL抗菌效率和抗吸湿性的方法，在一定程度上减少了其作为抗菌物质的应用限制。
