Abstract: The amino acid composition of 13 germplasms of Chinese prickly ash (collected from 13 different areas) was analyzed by using an automatic amino acid analyzer and the nutritional value was evaluated by ratio of amino acid (RAA), ratio coefficient of amino acid (RC), score of ratio coefficient of amino acid (SRCAA) and ratio between amino acid content and taste threshold (RCT). The results showed that each sample contained 17 amino acids, including all essential amino acids except tryptophan, with total amino acid contents ranging from 5.82% to 10.9%. The ratios of essential to total amino acid (EAA/TAA) were in the range of 0.17–0.33, and the ratios of essential to non-essential amino acid (EAA/NEAA) ranged from 0.21 to 0.48, which were lower than the FAO/WHO reference values of 0.4 and 0.6, respectively. The medicinal amino acids accounted for about 58% of the TAA content in Chinese prickly ash peel, which was the highest (6.70%) in the pericarp of Chenjiagelao thornless prickly ash (ZB1), accounting for 61% of the TAA content. The content of medicinal amino acids in prickly ash peel varied depending on the germplasms, but the proportions of medicinal amino acids in TAA were identical. According to the amino acid scores, methionine and cysteine were the first limiting amino acids in the pericarp of Chinese prickly ash, and aspartic acid, a umami amino acid, and had a significant effect on the flavor of Chinese prickly ash. The 13 germplasms of Chinese prickly ash were classified into 3 categories by using cluster analysis, and Chenjiagelao thornless prickly ash had the highest nutritional value. Therefore, Chenjiagelao thornless prickly can be used as an ideal source of protein in the development and utilization of Chinese prickly ash.

Key words: Zanthoxylum bungeanum, amino acid composition, taste-active amino acids, medicinal amino acid, clustering analysis