酶法酯交换制备塑性脂肪工艺优化及氧化稳定性研究

Optimization enzymatic interesterification process toproduce plastic fat and study of oxidative stability

以棕榈硬脂、油茶籽油及棕榈仁油为原料,利用酶法酯交换制备塑性脂肪。在单因素实验的基础上,采用Design Expert软件进行响应面优化设计,反应条件包括:反应时间、反应温度和酶添加量,以滑动熔点作为衡量指标。优化后得到最优反应条件为:反应时间4.2 h,反应温度64℃,酶添加量为7.2%,在最优反应条件下的酶法酯交换产物的实际滑动熔点可达37.9℃。对物理混合、酶法酯交换以及化学酯交换样品进行了氧化稳定性研究,在储藏30 d内物理混合样品的过氧化值为1.13~120.46 meq/kg,低于酶法酯交换样品(1.16~138.88 meq/kg)及化学酯交换样品(1.26~148.49 meq/kg)。物理混合样品的氧化稳定性高于酶法酯交换样品,酶法酯交换样品的氧化稳定性高于化学酯交换样品。

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 4.2 h(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 1.13~120.46 meq/kg which were lower than those of the enzymatic interesterified blends(1.16~138.88 meq/kg)and the chemical interesterified blends(1.26~148.49 meq/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.