Characterizing Diversity Based on the Chemical and Nutritional Composition of Shiitake Culinary-Medicinal Mushroom Lentinula edodes (Agaricomycetes) Commonly Cultivated in China

A comparative study was carried out on the chemical composition and nutritional value of six cultivated Lentinula edodes strains that are widely appreciated in China. The results demonstrated that all investigated L. edodes were good sources of protein (14.87%-27.13%), carbohydrates (62.03%-75.56%), and dietary fiber (35.88%-42.49%) and had low ash (5.24%-6.38%) and low fat (0.80%-1.70%) content. There were significant differences among different cultivars. Shenxiang 215 had high crude protein and dietary fiber contents. Potassium was the most abundant mineral element, followed by phosphorus. Different cultivars exhibited distinct fatty acid compositions and free amino acid profiles. Shenxiang 215 had high essential amino acid content. Polyunsaturated fatty acids were predominant in cultivars 0912, Huxiang F4, and Huxiang F2; however, monounsaturated fatty acids were predominant in other strains. Cultivar 0912 had a better mineral and polyunsaturated fatty acid profile. The amino acid profile and protein quality were systematically investigated referring to the latest version of international amino acid reference patterns, including the amino acid score, ratio coefficient of amino acid, ratio coefficient score of amino acid, essential amino acid index, and protein digestibility- corrected amino acid score. The results demonstrated that Shenxiang 18 had better protein quality. These findings provide a reference for breeders to select parents for directional quality breeding.