化学和物理精炼方法对小麦胚芽油品质劣变的影响

Study on the Effects of Chemical and Physical Refining Processes on the Deterioration in the Quality of Wheat Germ Oil

摘要:

为提高精炼的小麦胚芽油品质质量，该文研究了化学和物理精炼过程中小麦胚芽油的品质劣变程度。结果表明：化学精炼的小麦胚芽油，酸价降至0.18 KOH/(mg/g)，反式脂肪酸含量由毛油的未检出增加到0.07%，生育酚含量损失了37.14%。物理精炼的小麦胚芽油，在真空残压≤60 Pa，在温度为200 ℃~240 ℃，时间为2 h~8 h条件下脱酸，酸价降为5.49 KOH/(mg/g)~0.19 KOH/(mg/g)，反式脂肪酸含量为0.10%~3.13%；过氧化值为1.61 mmol/kg~4.33 mmol/kg，茴香胺值13.76~59.3；生育酚含量减少26.68%~85.90%。由其试验结果对比知，化学精炼对小麦胚芽油品质劣变的影响明显小于物理精炼，尤其是防止反式脂肪酸含量增加、维生素E含量损失等方面显著，是一种适合富含高不饱和脂肪酸、维生素E等功能性营养成分类型的油脂的精炼方法。

Abstract:

In order to improve the quality of refined wheat germ oil, the degree of deterioration in the quality of wheat germ oil during chemical and physical refining was investigated. For the wheat germ oil processed by chemical refining, the acid value dropped to 0.18 KOH/(mg/g), the trans fatty acid content increased to 0.070% from an undetectable level in crude oil, and the tocopherol content decreased by 37.83%. For the physical refining of wheat gream oil, deacidification was conducted under a residual pressure of ≤60 Pa in a temperature range of 200~240 ℃ for 2~8 h. The acid value dropped to 5.49 KOH/(mg/g)~0.19 KOH/(mg/g), the trans fatty acid content was between 0.13% and 3.13%, the peroxide value ranged from 1.61 mmol/kg~4.33 mmol/kg, the anisidine value ranged from 13.76~59.3, and the tocopherol content decreased by 26.68%~85.90%. Comparison of the two refining processes revealed that the chemical refining process had less significant effects on the deterioration of wheat germ oil quality than the physical refining process, particularly in regard to preventing the increase in the trans fatty acid content, and the loss in vitamin E content among others. Therefore, chemical refining is suitable for functional and nutritious oils rich in unsaturated fatty acids, vitamin E, etc.