聚合草叶蛋白的提取及饲用价值评价研究

Study on the Leaf Protein Extraction and Evaluation of Its Feeding Value in Symphytum pezegrinum L.

以聚合草为材料,研究其叶蛋白提取的最佳条件及其氨基酸组成,并采用氨基酸评分(AAS)及必需氨基酸指数(EAAI)2种方法对其饲用价值进行评价。结果表明:影响聚合草叶蛋白(LPC)提取率的因素依次为凝絮方法>固液比>加盐量,最佳条件组合为65%乙醇沉淀、固液比1∶7、含盐量0.3%。聚合草叶蛋白氨基酸总量19.65%,必需氨基酸的含量占总氨基酸含量的44.2%,呈味氨基酸的含量占总氨基酸含量的36.5%;并满足总必需氨基酸/总氨基酸(TEAA/TAA)>0.4,总必需氨基酸/总非必需氨基酸(TEAA/NEAA)>0.6;叶蛋白AAS和EAAI分别为47.5和0.916,高于同期苜蓿叶片(对应分别为30、0.881)。聚合草叶蛋白氨基酸组成平衡且优质。

To study the grass leaf protein extraction conditions in Symphytum pezegrinum L.and evaluate its feeding value,essential amino acid score（AAS） and essential amino acid index（EAAI） were determined by RP-HPLC.The result showed that the sequence of the factors in affecting extraction ratio of the LPC was flocculation method,solid-liquid ratio and the amount of adding salt.The optimum combination condition was that solid-liquid ratio of 1∶7,adding 0.3% salt and ethanol precipitation method.The aggregate total amount of 19.65% grass-protein amino acids,essential amino acids accounted for 44.2%,flavor of amino acids was 36.5%.While meeting the EAA/TAA0.4,EAA/NEAA0.6;Leaf protein AAS and EAAI were 47.5 and 0.916,respectively.It was higher than the same period in alfalfa leaves（30,0.881）.The results showed that aggregate balance of amino acid composition of grass and roots and high-quality of Symphytum pezegrinum L.,and have comprehensive development and utilization of high value.