Physicochemical Stability of Lycium barbarum Pigment-riched Microemulsion

Lycium barbarum pigment-riched microemulsions had small droplet size and it was transparent,so it was sensitive to external environment. The influence of food environment factors on the microemulsion was studied. The results showed that:the retention rate of pigmentsin microemulsions was above 80% at 4 ℃ after 10 days storage.The acidic conditions(pH3.5~5.5)would affect the stability of the microemulsion.The 5% NaCl would not affect the stability of the microemulsion.The droplet size increased(from about 30 nm to 120 nm)and the emulsions was cloudy after heating treatment. The degradation of pigment was slow down by adding antioxidants in the emulsion at 55 ℃ after 6 days storage.The retention rate of pigments was 73.8%~81% when adding 0.2 g/kg fat-soluble antioxidant system and retention rate was about 33% when adding 2 g/kg V_C. EDTA-2Na added 0.05 g/kg could slightly improve the stability of microemulsion.