Abstract:The effects of the mass ratio of chloroacetic acid to schizophyllan, reaction time, and reaction temperature on the degree of substitution in carboxymethyl schizophyllan were studied using response surface experiments. The in vitro weight method and body surface instrument method were used to study the moisturizing effects of carboxymethyl schizophyllan, which were then compared with the commonly used cosmetic moisturizers glycerol (Gl) and hyaluronic acid (HA). The response surface experiments showed that, under the optimum conditions ( themass ratio of chloroacetic acid to schizophyllan of 2.38, reaction temperature of 61.58 ℃, and reaction time of 2.82 h), the maximum degree of substitution (0.54) was obtained. In vitro test results showed that under relative humidity conditions of 43% and 81%, the moisture absorption rates of the samples were in the order of carboxymethyl schizophyllan > glycerol > hyaluronic acid > schizophyllan. Under dry environment conditions using silica gel, the moisture retention rates of the samples were in the order of glycerol > schizophyllan > carboxymethyl schizophyllan > hyaluronic acid. Under relative humidity of 43%, the moisture retention rates of the samples were in the order of glycerol > carboxymethyl schizophyllan > hyaluronic acid > schizophyllan. The skin moisturizing test showed that the moisturizing effect of carboxymethyl schizophyllan was significantly higher than that of hyaluronic acid and lower than that of glycerol, and the water-locking effect of carboxymethyl schizophyllan was stronger than those of glycerol and hyaluronic acid.
