米糠油萃取脱酸结合吸附脱酸工艺效果研究

Deacidification effect of rice bran oil by extraction-adsorption method

为了在脱酸的同时尽可能保留米糠油中的营养成分,采用乙醇萃取脱酸结合碱性微晶纤维素吸附脱酸的低温物理脱酸技术对米糠油进行脱酸。以乙醇萃取脱酸米糠油为原料,以脱酸率为考察指标,采用单因素实验和正交实验对米糠油的吸附脱酸工艺条件进行了优化,同时对比了碱炼脱酸与乙醇萃取脱酸结合吸附脱酸对米糠油品质的影响。结果表明:最佳吸附脱酸工艺条件为碱性微晶纤维素添加量3.0%、吸附时间2.0 h、吸附温度40℃,在此条件下米糠原油经乙醇萃取脱酸结合吸附脱酸处理后,酸值(KOH)由35.04 mg/g降到0.92 mg/g,谷维素的保留率为73.0%,总甾醇保留率为74.3%,总生育酚保留率为56.5%;而米糠原油经碱炼脱酸处理后,酸值(KOH)由35.04 mg/g降到1.16 mg/g,谷维素的保留率为60.1%,总甾醇保留率为65.6%,总生育酚保留率为44.6%。可见,与传统碱炼脱酸相比,萃取脱酸结合吸附脱酸的方法对米糠油中谷维素、甾醇、生育酚的保留率更高,对游离脂肪酸的脱除效果更好。

In order to retain nutrients in rice bran oil as much as possible while deacidifying,a low-temperature physical deacidification technology of ethanol extraction deacidification combined with alkaline microcrystalline cellulose adsorption deacidification was used to the deacidification of rice bran oil.The rice bran oil deacidified with ethanol extraction method was used as material,and the deacidification process of alkaline microcrystalline cellulose adsorption method was optimized by single factor experiment and orthogonal experiment using deacidification rate as the index.At the same time,the effects of alkali refining and ethanol extraction combined with adsorption deacidification on the quality of rice bran oil were compared.The results showed that the optimal conditions for adsorption deacidification method were as follows:alkaline microcrystalline cellulose amount 3.0%,adsorption time 2.0 h,and adsorption temperature 40℃.Under the optimal conditions,the acid value of rice bran oil decreased from 35.04 mgKOH/g(crude oil)to 0.92 mgKOH/g,the retention rate of oryzanol was 73.0%,the total phytosterol retention rate was 74.3%,and the total tocopherol retention rate was 56.5%.The acid value of rice bran oil with alkali refining decreased from 35.04 mgKOH/g(crude oil)to 1.16 mgKOH/g,and the retention rates of oryzanol,total phytosterol and total tocopherol were 60.1%,65.6%and 44.6%,respectively.In conclusion,compared with traditional alkali refining,extraction combined with adsorption deacidification method has higher retention rate of oryzanol,phytosterol and tocopherol in rice bran oil,and better removal effect of free fatty acids.