瓊麻濃縮葉蛋白之抽取試驗

Abstract

瓊麻（Agava sisalan）葉片及其製麻麻渣中含有6-9%粗蛋白，其中以水溶性及碱溶性蛋白質佔大部分，約為純蛋白質之85%。葉蛋白之抽出則以水及0.03-0.1N 氫氧化鈉溶液為最佳溶媒。加稀鹽酸調節pH 值至3.5-4.0，則為較適宜之蛋白質凝聚法。蛋白質回收率依原料不同而異，鮮瓊麻葉片，濕式製麻麻渣及乾式製麻麻渣分別為47%、66%及30%。 經一般成分及胺基酸組成分析結果發現，瓊麻濃縮葉蛋白之粗蛋白質含量28.4%，粗脂肪30.2%，粗纖維4.5%，灰分8.8%；必須胺基酸中則以羥丁胺酸及蛋胺酸含量稍低。將葉蛋白產品再經脫脂處理後可使粗蛋白質含量提高至38%。抽取蛋白後之殘渣仍含有多量粗纖維及碳水化合物。 The leaves of sisal (Agava sisalan) and its fiber residue contained 5-9% crude protein. Most of them were water soluble (albumin) and alkaline soluble (glutelin) protein, about 85% of simple protein. The best solvent of leaf protein extraction were water and dilute alkaline solution. The suitable coagulation method for sisal protein is that adjust pH value to the range of 3.5 to 4.0 with dilute hydrochloric acid. The recovery of protein for fresh sisal leaves, wet fiber residue and dried fiber residue were 47%, 66% and 30%, respectively. According to the chemical analysis and amino acid composition, the sisal LPC was found containing 28.4% crude protein, 30.2% crude fat, 4.5% crude fiber, 8.8% ash and less threonine and methionine. Residues of protein extraction contained much more crude fiber and carbohydrate. Defat treatment could make the protein content of sisal LPC increased to 38%.