Study On Chemical Constituents Of Stropharia Rugosoannulata And Quality Evaluation Based On GC-MS And Intelligent Sensory Technology

Stropharia rugosoannulata Farl.ex Murrill is a rare edible fungus with rich nutrition and delicious taste.It contains many chemical components such as flavonoids,phenols,and sterols,and has extremely high edible and medicinal value.In this study,the chemical components of fruiting bodies of Stropharia rugosoannulata were extracted,separated,purified and identified.The components of seven Stropharia rugosoannulata with different matrices were analyzed by GC-MS,and the flavor of Stropharia rugosoannulata with different matrices was analyzed by electronic nose and electronic tongue,to evaluate the quality of Stropharia rugosoannulata from the perspective of components.A plurality of separation methods such as silica gel column chromatography,medium pressure preparation chromatography,gel column chromatography,preparative high performance liquid chromatography and the like are adopted to separate four compounds from fruiting bodies of Stropharia rugosoannulata,and the structures of the compounds are identified by nuclear magnetic resonance spectroscopy and mass spectrometry as cerevisterol(1),p-hydroxybenzoic acid(2)and(2R*)-N-{(1S*,2R*3E,7E)-1-[(β-D-glucopyranosyloxy)methyl]-2-hydroxy-8-methylheptadeca-3,7-dienyl}-2-hydroxyeicosanamide(3)and uridine(4).Among them,phydroxybenzoic acid,(2R*)-N-{(1S*,2R*3E,7E)-1-[(β-D-glucopyranosyloxy)methyl]-2-hydroxy-8-methylheptadeca-3,7-dienyl}-2-hydroxyeicosanamide and uridine were isolated from Stropharia rugosoannulata for the first time.Based on the GC-MS fingerprint analysis of the impact of seven different substrates on the quality of Stropharia rugosoannulata,ten common peaks were labeled,and the similarity of each chromatogram with the reference chromatogram was 92.8%-98.6%,showing good similarity and uniform quality.The chemical pattern recognition analysis of that common peak of Stropharia rugosoannulata in seven different substrate was carried out.the result showed that the components of Stropharia rugosoannulata in the substrate of straw,straw: corn cob 1: 0.9,corn stalk and bamboo chip are similar,while the components of Stropharia rugosoannulata in the substrate of soybean stalk and sesame stalk are similar.the addition of wood chips in the substrate results in a large difference in the components of Stropharia rugosoannulata.compared with other substrates,the ones in the substrate of sesame stalk,soybean stalk,straw: wood chips 1: 1 are better in quality,Besides,five landmark components affecting the quality of seven different substrates of Stropharia rugosoannulata were screened out,which were 2-pentyl furan,benzaldehyde,phenylethanol,1-hexadecene and propanolide,respectively.By comparing the common and unique components of Stropharia rugosoannulata containing straw in the three matrices,it was found that the addition of wood chips in the straw substrate would increase the contents of heterocyclic compounds and ester compounds in Stropharia rugosoannulata,and the addition of corn cob in the straw substrate would increase the acid substances in Stropharia rugosoannulata.There were some differences in the components of Stropharia rugosoannulata from different substrates,and the above analysis could be used as the basis for evaluating the quality of Stropharia rugosoannulata from different substrates.GC-MS combined with electronic nose and electronic tongue,we found that there were significant differences in the flavor of Stropharia rugosoannulata from seven different matrices.A total of 73 volatile flavor components were detected by GC-MS,including aldehydes,ketones,alcohols,esters,acids and other components.Among them,20 substances contributed to the flavor,with isovaleraldehyde,decanal,and 2-methylbutyric acid as the major contributors,possessing the aroma of malt,fruit,and fat.The results of principal component analysis indicated that the aroma qualities of straw: wood dust 1: 1,sesame stalk and straw: corn cob 1: 0.9 substrate were good.Based on the analysis of the overall aroma and taste information provided by the electronic nose and electronic tongue,the response strength of each sample to the electronic nose feature sensor was consistent with the ranking of the quality evaluation models.GC-MS combined with electronic nose could well analyze the odor of samples.The bitter taste of Stropharia rugosoannulata cultured in the wood chip substrate and the soybean stalk substrate is more obvious,the fresh taste of Stropharia rugosoannulata cultured in the corn cob substrate or the corn stalk substrate can be improved,and the sweet taste and the fresh taste of Stropharia rugosoannulata cultured in the sesame stalk substrate can be improved.Based on the comprehensive aroma and taste evaluation,the straw: corn cob 1: 0.9 and sesame stalk substrate Stropharia rugosoannulata had good overall flavor quality.The straw: corn cob substrate 1: 0.9Stropharia rugosoannulata had fruity and nutty aroma and rich umami flavor.The Stropharia rugosoannulata with sesame stalk substrate had fruity and malt aroma and the main taste was umami and sweet.The research results could provide a theoretical reference for the flavor component analysis of Stropharia rugosoannulata and the development and utilization of Stropharia rugosoannulata flavor products.