玉米胚预榨毛油和浸出毛油品质及综合脱色效果的研究

研究了玉米胚预榨浸出生产中所得预榨毛油和浸出毛油的品质及其脱色效果和脱色过程中营养成分的保留率。结果显示,预榨毛油比浸出毛油的色泽浅、维生素E含量高、酸价也较低;添加相同量的活性白土分别对两种毛油进行吸附脱色,预榨毛油较浸出毛油脱色率平均高出约4.6%;白土用量4%时,脱色预榨毛油的色泽基本达到玉米油国标中二级油的指标,而浸出毛油即使在白土用量6%时其色泽也很难达到二级油指标;经吸附脱色,预榨毛油中植物甾醇和维生素E保留率普遍高于浸出毛油,在白土用量5%时,预榨毛油较浸出毛油甾醇保留率高出14%,不同白土用量,预榨毛油比浸出毛油甾醇保留率平均高出约10%;白土用量2%时,预榨毛油较浸出毛油维生素E保留率提高约5.6%;两种玉米毛油所含维生素E中4种生育酚及4种生育三烯酚都存在,组分齐全;吸附脱色过程中γ-生育酚和β-、γ-生育三烯酚的损失较明显,其他组分含量的损失较少。因此,合理的玉米油精炼应将预榨毛油和浸出毛油分别进行适度精炼,以提高吸附脱色效果和营养成分保留率。

The comparison of the quality and comprehensive decolorization effect of crude corn germ oil obtained respectively by pre-pressing and leaching process

The quality,comprehensive decolorization effect and nutrient retention of crude corn germ oil obtained from the pre-pressing and leaching stages in the process of pre-pressing extraction technics were studied.The results show that the color of crude oil got from the prepressing stage is lighter than the crude oil got from the extraction process,also the acid value is lower than it.But the content of vitamin E is higher than the extracted oil.Adsorption bleaching experiment has been made for the two crude oil with the same amount of adsorption bleaching,the decoloring rate of prepressed oil is about 4.6% higher than the extracted oil.The pre-pressed oil can reach the secondary standards set by the national standard when the dosage of activated clay is 4%.But extracted oil is difficult to achieve the national standard even the dosage of activated clay is 6%.In addition,in the process of bleaching,the retention rate of plant sterols andvitamin E of pre-pressed oil is generally higher than the extracted oil.When the dosage of activated clay is 5%,the plant sterols retention rate of pre-pressed oil is 14% higher than the extracted oil.Also the retention rate of pre-pressed oil,on average,about 10% higher than the extracted oil when adding different amount of clay.Compared with the extracted oil,the vitamin E retention rate of pre-pressed oil increases about 5.6%.And the four kinds of tocopherols and four kinds of tocotrienols are all exit in the vitamin E of these two oils.In the process of adsorption bleaching,theγ-tocopherol andβ-,γ-tocotrienols loss is obvious,and the loss of other components is less.Therefore reasonable refined process should do moderate refining respectively to the pre-pressed oil and extraced oil.If so,it can improve the effect of adsorption decolorizing and nutrients retention rate.