Microemulsion-based anthocyanin systems: effect of surfactants, cosurfactants, and its stability

Abstract

Anthocyanins exhibit natural antioxidants but exhibit poor stability and low oil solubility. Therefore, increasing the stability and fat solubility of anthocyanins is necessary to broaden their applications. In our experiment, an anthocyanin microemulsion system was constructed and its stability was investigated. At an oil phase and emulsifier ratio of 7:3, the hydrophilic oil-wet value reached 7.5 and the Km was 2:1. Furthermore, the microemulsion area was the largest. The bicontinuous region of the microemulsion exhibited optimal experimental conditions and resulted in a microemulsion containing 425.54 ± 1.58 μg/g anthocyanins. The anthocyanin microemulsion was a water-in-oil type, with a particle size of 0.07 ± 0.009 μm. Moreover, the temperature, light, and sample observation tests showed that the anthocyanin retention rate in the microemulsion was higher than that in the anthocyanin solution. Low-concentration NaCl and less than 9% of glucose and sucrose exerted no significant influence on the anthocyanin microemulsion stability.

Keywords

• Anthocyanins
• Microemulsion
• Pseudo-ternary phase diagram
• Stability