Effect Of Flammulina Velutipes Root Fermentation Broth On The Quality And Flavor Of Its Fruiting Body

Flammulina velutipes,which belongs to basidiomycete,has high edible and medicinal value.In recent years,the production of factory-made Flammulina velutipes has developed rapidly,the large amount of Flammulina velutipes roots(the base of the stipe)discarded in the production process has not been rationally utilized.It has been proved that the Flammulina velutipes root contains various nutrients such as polysaccharides and proteins.Similarly,the fixing water as a waste of the edible mushroom processing industry has also been proven to have a variety of nutrients.Therefore,in this paper,Flammulina velutipes root fermentation broth was prepared by natural fermentation of Flammulina velutipes root and fixing water.Pac Bio SMRT sequencing technology was used to analyze its bacterial microbial community diversity and metabolic function.Added it to the Flammulina velutipes culture material at a ratio of 0%,6.7%,13.4% and 20.1%.Divided into a control group and three treatment groups of E1,E2 and E3.To study its effects on the yield,nutrients and flavor components of Flammulina velutipes.The main results are as follows:1.7 bacterial Phylum such as Firmicutes(51.74%)and Proteobacteria(46.47%),100 bacterial genus such as Lactobacillus(42.37%)Pseudomonas(9.28%),190 bacterial species such as Lactobacillus hilgardii(37.55%)and Klebsiella oxytoca(5.55%)were identified in the Flammulina velutipes root fermentation broth.Prediction of PICRUSt gene indicates that bacterial microbes in fermentation broth share 41 metabolic functions such as membrane transport,carbohydrate metabolism and amino acid metabolism.2.The yield,biological efficiency and soluble sugar content of the E2 treatment group were the highest,454.1±10.42 g,137.84±3.16% and 6.52±0.05%,respectively,which were4.5%,5.9% and 9% higher than the control group.The moisture content of the control group was the highest 88.02±0.06%,and the lowest moisture content of the E1 treatment group was85.81±0.23%.The crude fiber,soluble protein and crude fat contents of the E3 treatment group were the highest,0.97±0.02%,0.90±0.02‰ and 0.29±0.01%,respectively,which were43%,32% and 11% higher than the control group.3.16 kinds of free amino acids were detected in the four groups of Flammulina velutipes samples.The total amino acids and essential amino acids contents of E2 treatment group were the highest,4.514±0.018 mg/g and 1.498±0.015 mg/g,respectively,which was24.77% and 25.36% higher than the control group.The E1 treatment group had the highest umami amino acids contents,1.287±0.009 mg/g,which was 21.42% higher than the control group.In the nucleotides assay,the E2 treatment group had the highest contents of umami nucleotides and flavor nucleotides,0.062±0.001 mg/g and 0.056±0.001 mg/g,respectively,which was 88.88% and 106.51% higher than the control group.The EUC value was the highest in the E2 group,10.90±0.40,which was 143.3% higher than the control group.Six kinds of taste values were measured by electronic tongue.The E1 and E2 treatment groups showed the higher umami,sweet and salty taste value than the control group.The six taste values of the E3 treatment group showed higher.The E2 treatment group had the highest umami value,11.65?0.62,which was 21.86% higher than the control group.4.A total of 28 volatile components were detected in the four groups of Flammulina velutipes samples.Among them,14 kinds of volatile components were detected in the control group,16 in the E1 group and E2 group,and 20 in the E3 group.The control group consisted of eight substances,such as hydrocarbons,aldehydes,acids,esters,ketones,and alcohols.Compared with the control group,the E1 and E2 treatment groups did not detect acids.The E3 treatment group detected phenolic substances.3-octanol and 3-octanone are the main volatile components.Conclusions: The bacterial diversity of Flammulina velutipes root fermentation broth was analyzed by Pac Bio SMRT.The dominant species was Lactobacillus hilgardii,followed by Klebsiella oxytoca.The addition of Flammulina velutipes root fermentation broth can increase the yield,biological efficiency and nutrients of Flammulina velutipes,improve its flavor.Comparing the measured indexes,13.4% of the Flammulina velutipes fermentation broth was the best.