正己烷和亚临界法萃取玉米皮油的性质比较分析

COMPARISON AND ANALYSIS OF CHARACTERISTICS OF CORN FIBER OILS EXTRACTED USING HEXANE AND SUBCRITICAL BUTANE

利用正己烷和亚临界萃取法得到了玉米皮油,并对其理化指标、玉米皮油脂肪酸组成及植物甾醇含量和组成进行了分析研究。结果表明：正己烷萃取的玉米皮油的过氧化值80.5 mmol/kg,酸值14.8 mg/g,皂化值为162.5 mg/g,碘值111.8 g/100 g。亚临界萃取的玉米皮油的过氧化值90.3 mmol/kg,酸值12.7 mg/g,皂化值为164.3 mg/g,碘值114.4 g/100 g。气相色谱法测得玉米皮油的不饱和脂肪酸含量为77.0%~84.4%,其中50%以上为亚油酸。正己烷法和亚临界法得到的玉米皮油植物甾醇含量分别为6.4%和5.2%,其中所含的植物甾醇成分主要有菜油甾醇、谷甾烷醇、豆甾醇、β-谷甾醇和豆甾烷醇。所制得的玉米皮油可作为一种保健油脂,也可添加到食品中提高植物甾醇含量。

The present study was to investigate the physicochemical indexes, fatty acid compositions, phytosterol contents and compositions of corn fiber oils which were extracted using hexane and subcritical butane methods, respectively. The results showed that physicochemical characteristics of corn fiber oils extracted by hexane and subcritical butane were as follows： peroxide value of 80.5 mmol/kg and 90.3 mmol/kg, acid value of 14.8 mg/g and 12.7 mg/g, saponification value of 162.5 mg/g and 164.3 mg/g, and iodine value of 111.8 g/100g and 114.4 g/100 g, respectively. The fatty acid compositions of corn fiber oil were analyzed using gas chromatography, and the content of unsaturated fatty acids of corn fiber oils were 77.0%-84.4%, including more than 50% of linoleic acid. Phytosterols contents of corn fiber oils extracted by hexane and subcritical butane were 6.4% and 5.2%, respectively, which contained campesterol, sitostanol, stigmasterol, β-sitosterol and stigmastanol. It was concluded that the corn fiber oil extracted by subcritical butane could be used as a kind of health oil or used as additives in food to improve the content of phytosterols.