小米糠(胚)制油及油脂品质研究

Millet Bran(Embryo)Oil and its Oil Quality

小米糠按谷子加工过程的工序不同可分为细糠和抛光粉两部分,两部分混合后的混合糠即小米糠全糠,因其中含有小米胚,因此也称小米胚。细糠和抛光粉中主要组分的质量分数分别为粗脂肪11.56%和8.6%,粗蛋白10.63%和12.41%,粗纤维20.5%和2.25%;分别采用压榨法和溶剂浸出法提取细糠、抛光粉和混合糠中的油脂,检测结果显示,小米糠油的酸价为17.58~45.43mgKOH/g,过氧化值为0.083~0.226g/100g,其中抛光粉所制取小米糠油的酸价和过氧化值明显高于细糠及混合糠所制取小米糠油;小米糠油中含量最多的是亚油酸(67.13%~68.81%),其次为油酸(12.86%~14.71%)、棕榈酸(7.43%~8.21%)。小米糠油中8种VE组分齐全,α-生育酚和γ-生育酚含量较高,VE总含量为789~1287mg/kg;谷维素质量分数为0.40%~0.59%;甾醇质量分数为1.68%~2.08%,其中谷甾醇含量最高(779~932mg/100g),其次是谷甾烷醇;角鲨烯含量为102.45~126.22mg/kg。小米糠油是营养丰富的食用植物油。此外,小米糠蛋白质中除赖氨酸外其余的必需氨基酸评分(AAS)均大于100,小米糠蛋白是一种优质的蛋白质资源。

Millet bran can be divided into two parts:bran shorts and polished powder according to the different processing steps of millet. The millet bran is a mixture of these two parts, which is called mixed millet bran. Because it contains millet embryo, it is also called millet embryo. The mass fractions of main components in bran shorts and polishing powder were 11.56% and 8.6% of crude fat, 10.63% and 12.41% of crude protein, 20.5% and 2.25% of crude fiber, respectively. The oil in the bran shorts, polished powder and mixed millet bran was extracted by pressing method and solvent leaching method. The results showed that the acid value of millet bran oil was 17.58~45.43 mg KOH/g, the peroxide value was 0.083~0.226 g/100g. The acid value and peroxide value of millet bran oil obtained from polishing powder were significantly greater than that of oil obtained from bran shorts and mixed millet bran. The most abundant in millet bran oil was linoleic acid (67.13%~68.81%), followed by oleic acid (12.86%~14.71%), and then palmitic acid (7.43%~8.21%). There are 8 kinds of vitamin E components in millet bran oil, in which the content of α-tocopherol and γ-tocopherol was relatively high, and the total content of vitamin E was 789-1287 mg/kg. The mass fraction of oryzanol in millet bran oil was 0.40%~0.59%, the mass fraction of sterol was 1.68%~2.08%, among them, the highest content was sitosterin (779~932 mg/100g), followed by sitostanol. The content of squalene was 102.45~126.22 mg/kg. Millet bran oil was a nutritious edible vegetable oil. In addition, the amino acid score (AAS) of essential amino acids was greater than 100 except for lysine, which proveed that millet bran protein was a protein resource with high quality.