Phase Behavior and Antibacterial Activity of Food-Grade Eugenol-Based Microemulsions(食品级丁香酚微乳液相行为及其抑菌性)
摘要
To improve the hydrophilicity and antibacterial activity of eugenol, infinitely dilutive microemulsions of eugenol were constructed with Tween as the surfactant and lactic acid as the co-surfactant. The antibacterial activities of eugenol before and after micro-emulsification against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> were also investigated. The results of the pseudo-ternary phase diagrams showed that compared with Tween-40 and Tween-60, Tween-80 was more effective to increase the area of microemulsion single phase. The solubilization effect of lactic acid was improved with the increase lactic acid concentrations. When the mass ratio of eugenol and lactic acid was 1∶3, the area of eugenol microemulsion single phase was expanded to 78.8%. In the antibacterial activity test, the lower the Tween-80 content, the higher the lactic acid content in a certain scope, and the higher the antibacterial activity of eugenol microemulsions. When eugenol, lactic acid and Tween-80 was at a mass ratio of 1∶3∶6 in the microemulsion, the growth of two tested bacteria was completely inhibited at eugenol with a mass fraction of 0.05%. Moreover, the antibacterial activity of the complex system was significantly higher than that of single eugenol microemulsion without lactic acid. Therefore, microemulsions developed in this study could provide a feasible formulation for enhancing solubility and antibacterial effect of eugenol, and were expected to be used in the field of food antisepsis and preservation.(为提高丁香酚的亲水性和抑菌效果,以吐温为表面活性剂,乳酸为助表面活性剂,构建可无限稀释的丁香酚微乳液,并探究微乳化前后丁香酚抑制大肠杆菌和金黄色葡萄球菌的效果。拟三元相图的分析结果表明,与吐温-40和吐温-60相比,吐温-80更能有效增加微乳液单相区面积；乳酸的增溶效果随着乳酸添加量的增加而提高,当丁香酚与乳酸质量比为1∶3时,丁香酚微乳液单相区面积扩大至78.8%。抑菌特性研究结果显示:在一定范围内,随着吐温-80比例的降低,乳酸比例的增加,丁香酚微乳液的抑菌效果增强；当微乳液组分中丁香酚、乳酸与吐温-80的质量比为1∶3∶6时,质量分数0.05%的丁香酚可完全抑制2种受试细菌的生长,同时,该复合微乳液的抑菌活性显著高于不含乳酸的单一丁香酚微乳。研究开发的微乳液旨在为实现丁香酚的增溶增效提供可行的剂型,并有望用于食品防腐保鲜领域。)