以不同制油工艺制得的菜籽油为原料,比较研究了菜籽油的酸值、过氧化值、脂肪酸和甘三酯的组成及微量营养成分。结果表明:制油工艺对菜籽油的脂肪酸和甘三酯组成无显著性影响;水酶法制得菜籽油的酸值(KOH)相对较高,为0.995mg/g,但富含β-胡萝卜素、植物多酚,含量分别为5.40mg/kg和152.08mg/kg;浸出菜籽毛油富含生育酚和植物甾醇,含量分别为833.74mg/kg和6607.35mg/kg;精炼菜籽油的酸值(KOH)最低,仅为0.233mg/g,但精炼菜籽油的微量营养成分相对较少。分别以氧化诱导时间和DPPH自由基清除能力为指标,评价了不同制油工艺制得菜籽油的氧化稳定性,结果发现5种菜籽油的氧化稳定性大小是:水酶法菜籽油最强,精炼菜籽油最弱,而浸出菜籽毛油、热榨菜籽油和冷榨菜籽油介于其间,这一性质和油中的植物多酚和β-胡萝卜素合号晕疆薯正相美.
The acid values, peroxide values, compositions of fatty acid and triglyceride and trace compo- nents of rapeseed oils prepared by different extraction processes were comparatively studied. The results showed that there was no obvious effect of extraction process on compositions of fatty acid and triglyceride of rapeseed oil. The acid value of aqueous enzymatic extracted rapeseed oil was relatively higher (0.995 mgKOH/g), but the oil was rich in β- carotene and polyphenol with contents of 5.40 mg/kg and 152.08 mg/kg, respectively. The hexane extracted rapeseed oil had high contents of tocopherol and plant sterol, which were 833.74 mg/kg and 6 607.35 mg/kg ,respectively. The acid value of refined rapeseed oil was the lowest, only 0.233 mgKOH/g, while the content of trace components was relatively lower. The oxi- dative stabilities of rapeseed oils prepared by different extraction processes were evaluated with oxidative induction time and scavenging capacity on DPPH free radical as indexes. The results showed that the oxi- dative stability of aqueous enzymatic extracted rapeseed oil was the stongest, refined rapeseed oil was theweakest, hexane extracted rapeseed oil, hot pressed rapeseed oil and cold pressed rapeseed oil were in middle. These properties were significant- ly related to contents of polyphenol and β- caro- tene in different processed rapeseed oils.