Phase behavior, microstructural transition, antimicrobial and antioxidant activities of a water-dilutable thymol microemulsion

作者：Deng, Lingli; Taxipalati, Maierhaba; Sun, Ping; Que, Fei; Zhang, Hui^*

来源：Colloids and Surfaces B: Biointerfaces , 2015, 136: 859-866.

DOI：10.1016/j.colsurfb.2015.10.031

• Thymol
• Microemulsion
• Microstructure
• Antimicrobial
• Antioxidant

Pseudo ternary phase diagrams were constructed to assess the dilutability of thymol microemulsions using non-ionic (Tween 80), cationic (CTAB), and anionic (SDS) surfactants. We successfully constructed a thymol U-type microemulsion system using Tween 80 as surfactant and studied the microstructural transition along the dilution line at a 90/10 surfactant/oil mass ratio, with thymol and ethanol (3:1, w/w) as the oil phase. Differential scanning calorimetry analysis suggested that the microemulsions gradually inverted from the water-in-oil (W/O) (0-20% water) to the bicontinuous (25-35% water), and finally to the oil-in-water (O/W) (40-90% water) microstructures upon dilution, in good agreement with the conductivity measurements, while the theological results indicated the collapse of rod-like micelles followed by formation of spherical micelles in the O/W region. The activities of the U-type thymol microemulsions are structural dependent. The antimicrobial activity against Escherichia coli and Staphylococcus aureus decreased when the microemulsions transformed from W/O to bicontinuous and O/W structures, while the DPPH scavenging activity increased.

• 出版日期2015-12-1
• 单位浙江大学; 浙江经贸职业技术学院