亚东黑耳的氨基酸特征分析及蛋白质品质评价

亚东黑耳(Exidia sp.)是一种尚未实现人工栽培的珍稀食用菌,为发掘和利用其营养价值,在现行国际氨基酸模式谱的基础上,以氨基酸评分(AAS)、美国国家科学院医学研究所(IOM)模式评分、化学评分(CS)、氨基酸比值系数(RC)、氨基酸比值系数分(SRC)和必需氨基酸指数(EAAI)等多个参数为指标,系统地分析了亚东黑耳的氨基酸特征和蛋白质品质。结果表明,亚东黑耳中含有18种常见氨基酸,包括全部8种必需氨基酸;其粗蛋白含量与粮食作物接近,蛋白质中必需氨基酸含量充足(473.4 mg·g^-1 pro),其中亮氨酸含量较高(67.73 mg·g^-1 pro)。参数评估表明,亚东黑耳蛋白质中的必需氨基酸比例相对合理(RC值0.74～1.66,EAAI值129.11),基本符合国际推行的氨基酸平衡模式谱(AAS值均高于98.75%,IOM模式评分均高于100%),是相对优质的蛋白质,但其平衡性和含量均逊色于鸡蛋蛋白(CS值70.93%～128.30%)。本研究结果为进一步开发野生菌资源提供了科学基础。

Amino Acid Profile and Protein Quality of Exidia sp.

Exidia sp. is a rare edible fungus that has not been cultivated yet. To explore its nutrition value, the amino acid profile and protein quality were systematically investigated referring to the latest version of international amino acid reference patterns. Standard indicators, such as: amino acid score (AAS), IOM (Institute of Medicine) pattern score, chemical score (CS), ratio coefficient of amino acid (RC), score of ratio coefficient of amino acid (SRC) and essential amino acid index (EAAI) were analyzed. The results suggested that Exidia sp. contained 18 kinds of common amino acids, including all 8 essential amino acids. Its crude protein level was close to that of grain crops, the essential amino acids were sufficient (473.4 mg·g^-1), and the leucine content was high (67.73 mg·g^-1). Systematic assessment indicated that, in the Exidia sp. protein, individual EAAs (essential amino acids) were approximately balanced (RC=0.74~1.66, EAAI=129.11), which met the requirements of current international reference patterns (AAS values were higher than 98.75%, and IOM scores were higher than 100%). Exidia sp. protein was a relatively high-quality protein, though the contents and balance of essential amino acids were inferior to those of egg protein (CS=70.93%~128.30%). The study provides a scientific basis for further utilization of wild fungi resources.