不同产地水飞蓟籽油理化特性及脂肪酸组成比较

以5个主要产地的水飞蓟籽为原料,对水飞蓟籽的理化性质和水飞蓟籽油的理化特性、脂肪酸(全样、Sn-2位)组成及生育酚含量进行了分析比较。结果表明:不同产地水飞蓟籽的粗脂肪、粗蛋白质均存在极显著差异,其中粗脂肪含量为17.33%~25.54%;5个产地水飞蓟籽油理化性质的差异程度依次为过氧化值>酸值>皂化值>色泽、折光指数;水飞蓟籽油中共检测出8种脂肪酸,以亚油酸(44.74%~56.93%)、油酸(21.36%~32.75%)、棕榈酸(8.36%~9.60%)和硬脂酸(4.81%~6.23%)为主,其中不饱和脂肪酸含量77%以上,不同产地脂肪酸组成基本一致;Sn-2位主要脂肪酸分别为油酸(25.52%~42.07%)、亚油酸(57.93%~74.47%),含量较高的产地分别为河北和陕西;生育酚是油脂中的主要抗氧化物质,5个地区水飞蓟籽油中仅检测出α-生育酚,含量为466.89~563.43 mg/kg,由高到低所对应的产地依次为河北、广西、安徽、陕西、黑龙江。

Comparison of physicochemical properties and fatty acid composition of Silybum marianum seed oils from different regions

Silybum marianum seed from five production regions were tested as raw materials on physicochemical properties.Then physicochemical properties,fatty acid compositions(full sample and Sn-2 position),and tocopherols in Silybum marianum seed oil were also analyzed and compared.Results showed that crude fat and crude protein contents had extremely significant difference among Silybum marianum seeds from different regions,and the crude fat content was 17.33%-25.54%.The degree of difference in physicochemical properties followed the order of peroxide value>acid value>saponification value>color and refractive index.8 fatty acids including linoleic acid(44.74%-56.93%),oleic acid(21.36%-32.75%),palmitic acid(8.36%-9.60%)and stearic acid(4.81%-6.23%)were detected in Silybum marianum seed oil as the main constituents,wherein unsaturated fatty acid content exceeded 77%.Fatty acid compositions in Silybum marianum seed oils from different regions were basically the same.Oleic acid(25.52%-42.07%)and linoleic acid(57.93%-74.47%)were their characteristic Sn-2 position fatty acids,and the samples with higher Sn-2 position fatty acid content were from Hebei and Shaanxi.Tocopherols were the main antioxidant in oils and fats.Onlyα-tocopherol was detected in the Silybum marianum seed oil with the contents of 466.89 mg/kg to 563.43 mg/kg.The contents ofα-tocopherol in Silybum marianum seed oil decreased in the following order:Hebei>Guangxi>Anhui>Shaanxi>Heilongjiang.