Amino acid composition and nutritional evaluation of six Auricularia cornea Ehrenb.germplasms
[Objective]The purpose of the study was to investigate the amino acid composition and nutritional diffe-rences among various Auricularia cornea Ehrenb.germplasms,and to provide a scientific reference for the rational deve-lopment and utilization of A.cornea resources.[Method]Amino acids and conventional nutritional components of six A.cornea germplasms(SH,QB,CB,FS,HY and CF)were determined.Comprehensive evaluation of nutritional diffe-rences was conducted based on principal component analysis,cluster analysis,and indicators such as amino acid ratio(RAA)and amino acid ratio coefficient score(SRC).[Result]All six germplasms of A.cornea contained seventeen types of amino acids,and the total amino acid content ranged from 4.139 g/100 g to 6.314 g/100 g.The total amino acid content of QB was the highest,and was significantly higher than that of the other five germplasm(P<0.05,the same below).The contents of aspartate(Asp)and glutamic acid(Glu)were relatively high,and the contents of cysteine(Cys),methio-nine(Met),tyrosine(Tyr)and isoleucine(Ile)were relatively low.The first limiting amino acid was Met+Cys and the second limiting amino acid was lysine(Lys).The flavor amino acids were mainly umami amino acids,and the ratios of essential amino acids to total amino acids were higher than that of the Food and Agriculture Organization of the United Na-tions/World Health Organization(FAO/WHO)model.SRC ranged from 63.999 to 75.217,with FS and CB being rela-tively high.Obvious nutritional differences were observed among different A.cornea germplasms.Essential amino acid content ranged from 1.515 to 2.227 g/100 g,with QB and HY being significantly higher than other germplasms.Protein content ranged from 5.508 to 7.707 g/100 g,with HY being the highest.Crude polysaccharide content ranged from 3.827 to 10.140 g/100 g,calcium content ranged from 1.790×103 to 4.867×103 mg/kg,ferrum content ranged from 17.007 to 180.667 mg/kg,and ash content ranged from 1.967 to 5.400 g/100 g,all with FS being the highest.Crude fat content ranged from 0.100 to 0.500 g/100 g,zinc content ranged from 6.333 to 10.800 mg/kg,and selenium content ranged from 0.015 to 0.084 mg/kg,with CB being the highest and significantly higher than the other germplasms.Principal component analysis result showed that the comprehensive amino acid scores of the six germplasms were ranked QB>HY>FS>CF>CB>SH.Cluster analysis grouped the six germplasms into three categories.SH,CB and CF were clustered into groupⅠwith relatively poor overall quality.FS was clustered individually into groupⅡwith moderate overall quality.QB and HY clustered into group Ⅲ with the best overall quality.[Conclusion]The tested six A.cornea germplasm exhibit a complete range of amino acids,a higher proportion of essential amino acids and good nutritional balance.Obvious differences are observed in amino acid composition and nutritional quality among different A.cornea germplasms,with QB and HY dis-playing the best overall nutritional quality.