Optimization enzymatic interesterification process to produce plastic fat and study of oxidative stability

Plastic fat was produced by enzymatic interesterification with palm stearin and camellia seed oil. Based on single factor experiments, the interesterification conditions was optimized by a response surface design through the Design Expert software,which included reaction time,reaction temperature and enzyme addition.The response value was the slipping melting point. The result of the optimization was 4.2h(reaction time),64℃(reaction temperature),7.2%(enzyme addition). Under this condition,the real response value was 37.9℃.Oxidative stability was compared to the samples physical blends,the enzymatic and chemical interesterified blends. The peroxidate values of the physical blend during the storage time for 30 days were 1.13~120.46meq/kg which were lower than those of the enzymatic interesterified blends(1.16~138.88meq/kg) and the chemical interesterified blends(1.26~148.49meq/kg). The study demonstrates the oxidative stability of physical blend was higher than that of the enzymatic interesterified blends and the enzymatic interesterified blends was more stability than the chemical interesterified blends.