脱酸米糠毛油品质对吸附脱色综合效果的影响

采用碱炼脱酸和水蒸汽蒸馏脱酸两种不同脱酸工艺所得米糠油进行吸附脱色试验,以米糠油脱色率及谷维素、甾醇、维生素E等营养成分保留率和反式脂肪酸生成量作为考察指标,分析研究待脱色米糠油品质对吸附脱色综合效果的。结果显示,在脱色率、VE保留率和反式酸含量方面碱炼脱酸米糠油的综合脱色效果优于水蒸汽蒸馏脱酸米糠油。碱炼脱酸米糠油的最佳吸附脱色条件为:凹凸棒石为吸附剂,用影响量为油重的4%,脱色时间30 min,脱色温度110℃。在最佳工艺条件下,测得米糠油脱色率为75.08%,脱色米糠油的色泽为Y35、R2.1(罗维朋比色槽25.4 mm),满足国标三级米糠油色泽要求;谷维素保留率为88.89%(脱色前后谷维素含量分别为0.90%、0.80%、),甾醇保留率为73.87%(脱色前后甾醇含量分别为2.32%、1.71%),维生素E保留率为82.90%(脱色前后维生素E含量分别为50.57 mg/100 g、41.92 mg/100 g);与水蒸汽蒸馏脱酸米糠油相比,相同脱色条件下,脱色率提高7.84%,维生素E保留率提高7.64%,但谷维素保留率下降4.74%,甾醇保留率下降4.58%。脱色前后碱炼脱酸米糠油中未检出反式酸,水蒸汽蒸馏脱酸米糠油中反式酸含量为0.40%,脱色后反式酸含量增加了0.02%。虽然谷维素和甾醇的保留率相对降低,但两者的保留率仍达到了88.89%、73.87%,脱色油中两者含量分别为0.80%、1.71%,单就脱色过程而言,营养成分保留率还是很高的。

Influences of deacidification quality of rice bran oil on comprehensive effect of adsorption bleaching

From the decolorization test of different deacidified rice bran oil, the influence of the quality of rice bran oil to the decolorization test was analyzed using the decolorization effect of rice bran oil and the retention rate of sterols and vitamin E as examination oryzanol, indicator. The study indicates： refining deacidification （chemical deacidification） process is better than the steam stripping deacidification （physical de- acidification） process. The optimum adsorption bleaching processing conditions of the refining rice bran oil are as follows. Attapulgite is used as decolorant, decolorant dosage 4%, bleaching tem- perature 110 ~C, bleaching time 30 min. Bleached rice bran oil is obtained through the verification tests under the conditions, the decoloring rate of the rice bran oil is 75.08G, the Lovibond color of the oil is Y35 R2. 1 （25.4 mm）, the retention rates of oryzanol, sterols and vitamin E are 88.89%, 73.87% and 82.90%, respectively. Compared with the steam stripping deacidification rice bran oil, its decoloring rate increases by 7.84%, the retention rates of vitamin E increase by 7.64%, the retention rates of oryzanol and sterols decease by 4.74% and 4.58%, respectively. The trans fatty acids are not detected in chemical deacidification rice bran oil samples, the trans fatty acids are detected in physical deacidification rice bran oil samples, its content are 0.40%, after decolorizing, the trans acid content increases 0.02 % in physical deacidifieation rice bran oil. Ahhought the retention rates of oryzanol and sterols are relatively low, their retention rates still reach 88. 89%, 73.87%, the content of them in bleached rice bran oil is 0.80%, 1.71%, if we just considerate the bleaching process, their retention rate is high.