Analysis of nutritional and flavor qualities among different varieties of Stropharia rugosoannulata

【Objective】 This study aimed to investigate the differences in agronomic traits，nutritional quality，and flavor characteristics among different varieties of Stropharia rugosoannulata， in order to provide a theoretical basis for standardized cultivation and flavor-oriented quality improvement for Stropharia rugosoannulata.【Method】 Stropharia rugosoannulata varieties，including Daqiugai No. 8，Huangqiugai No. 1，Chuanqiugai No. 2，and Qiugaigu No. 6，were selected as the research materials. The agronomic traits of the four varieties were determined， such as yield per unit area， pileus dia-meter， pileus thickness， stipe diameter， and stipe length were measured； the contents of nutritional components inclu-ding total protein， total sugar， fat and amino acids were determined. Gas chromatography-ion mobility spectrometry （GC-IMS） was adopted to determine the volatile components in different cultivars of Stropharia rugosoannulata，and flavor profiles were further interpreted using principal component analysis （PCA） and partial least squares-discriminant analysis （PLS-DA）.【Result】 Chuanqiugai No. 2 had the highest yield per unit area，relatively long pileus diameter， as well as the longest stipe diameter and stipe length among the four cultivars， with the yield per unit area reaching 4030.89 g/m²， which was significantly higher than that of the other three cultivars （P<0.05， the same below）. No significant difference was found in the total protein content of the four cultivars （P>0.05）； whereas the contents of total sugar， fat， and total amino acids showed significant differences， as the order of total sugar content was Qiugaigu No.6>Daqiugai No.8>Huangqiugai No. 1>Chuanqiugai No. 2， and Huangqiugai No. 1 had the most abundant amino acid types. A total of 72 volatile compounds were identified in the four cultivars of Stropharia rugosoannulata by GC-IMS. PCA showed that the cumulative contribution rate of the first two principal components was 74.3%. The PLS-DA model presented an interpretation rate of 91.4% and a prediction rate of 96.6%， indicating that the flavor profiles of the four cultivars could be effectively distinguished. Among the volatile components contained in the four cultivars，Daqiugai No.8 was dominated by aldehydes， Huangqiugai No. 1 by alcohols， ketones， and esters， Chuanqiugai No. 2 by ketones， and Qiugaigu No. 6 by alcohols and ketones.【Conclusion】 The genetic background of cultivars is the core factor determining the nutritional quality and the composition of volatile flavor substances of Stropharia rugosoannulata. Among the four tested cultivars， Chuanqiugai No. 2 exhibits the strongest capacity of biomass accumulation and adaptability， which can be regarded as a potential cultivar for understory ecological cultivation. Qiugaigu No. 6， Huangqiugai No. 1， and Daqiugai No. 8 have the cha-racteristics of high sugar content， rich amino acids， and aldehyde aroma respectively， which can be used as genetic resources for breeding specialized cultivars of Stropharia rugosoannulata.