围氏马尾藻的营养化学成分及评价

Chemical Composition and Nutritional Evaluation of Sargassum wightii

探寻围氏马尾藻的主要营养成分和多糖成分,为其开发利用提供理论基础。运用营养分析方法分析表明围氏马尾藻的矿质元素含量丰富,粗脂肪、蛋白质、碳水化合物分别为其干重的1.44%、11.78%和41.61%,总氨基酸的含量为6.63 g/100 g,必需氨基酸占氨基酸总量的45%,必需氨基酸与非必需氨基酸的比值是0.81,第一限制氨基酸为蛋氨酸+胱氨酸,第二限制氨基酸为赖氨酸,必需氨基酸指数为96,维生素B2和β-胡萝卜素分别为102μg/100 g和11.4μg/100 g。热水回流法提取围氏马尾藻多糖,脱蛋白后经醇沉及有机溶剂洗涤得到精制多糖,红外光谱分析显示多糖含有糖醛酸和硫酸酯基。综上,围氏马尾藻具有较高的营养价值,是一种高蛋白、低脂肪且富含矿物质和硫酸酯多糖的大型经济海藻,具有较大的开发潜力和市场前景。

The objective of this study was to explore the main nutritional composition and polysaccharides of Sargassum wightii,and to provide a theoretical basis for exploiting and utilizing the natural resource of S. wightii. By using nutritional analysis method,the seaweed S. wightii was proved to have abundant content of mineral elements and 1. 44% fat,11. 78% protein,as well as 41. 61% carbohydrates. The total amino acid content was 6. 63 g/100 g which included 45%of essential amino acids,and the proportion of essential amino acid to non-essential amino acid was 0. 81. Methionine and Cystine were determined to be the first limiting amino acid,and Lysine was the second limiting amino acid,and the essential amino index was 96 for S. wightii. Meanwhile,vitamin B2 and beta-carotene were also detected in S. wightii,whose contents were 102 μg/100 g,11. 4 μg/100 g,respectively. In addition,the crude polysaccharide was extracted from S.wightii by hot-water,followed by being refined by Sevage deproteinization method combining ethanol precipitation method and organic solvent cleaning method. The IR spectrum analysis indicated that refined polysaccharide contains uronic acid and sulphated ester groups. The above results showed that S. wightii was a kind of seaweed with high nutritional value,which may provide high protein,low fat and sulfated ester polysaccharide for health foods,and had important economic value and broad market prospect.