Abstract:Oleogel is not only widely used in functional foods, but also has important application prospects in the fields of pharmaceutical preparations and cosmetics. Two citric acid monoesters were synthesized by direct esterification, and their properties of gel were studied in this paper. The solution aggregation behavior and micellar thermodynamics of these two citric acid monoesters were analyzed by surface tension meter, conductivity meter and dynamic light scattering instrument, and the results showed that the critical micelle concentrations of lauryl citric acid monoester and isodecyl citric acid monoester at 25 oC were 3.30 mmol/L and 6.40 mmol/L, respectively. In addition, the effects of ionic strength on the formation of micelles were also studied, and the results showed that inorganic salts not only affected the aggregation number of micelles, but also reduced the micelle size of isodecyl citric acid monoester and lauryl citric acid monoester by about 10 nm and 200 nm. The studies of oleogel properties indicated that both of the two citric acid monoesters could form the gel with vegetable oil. The minimum concentration was 7% and the temperatures of the sol-gel transition were all between 45~53 oC. Also, the results of biocompatibility studies showed that the two citric acid monoesters had no significant effect on the growth of microorganisms at a concentration of 200 mg/L, indicating that the citric acid monoesters had good biocompatibility.
