Optimization Of Aspergillus Oryzae Fermentation Conditions Of Mung Bean Skin And Its Product Analysis

Mung bean skin is a layer of epidermis wrapped around the cotyledon of mung bean.It is rich in active substances such as phenolic acids,flavonoids and a large amount of dietary fiber.In this study,mung bean peel was used as the main raw material,and aspergillus oryzae was used to ferment it,the fermentation conditions of Aspergillus oryzae were explored,and the composition and flavor substances of fermentation products were analyzed.Using fermented product as raw material,the beverage of fermented product of mung bean skin was prepared and its sensory evaluation was carried out,which provided a new idea for the utilization of mung bean skin.Based on the total flavonoid and phenolic contents,2022,40827 and 40864 were selected as fermentation strains to optimize the fermentation conditions.40827 m Aspergillus was used as single strain of fermentation,and 2022+40827 and2022+40864 were used as mixed fermentation strains.The optimal fermentation conditions were determined as follows: 40827 m aspergillus single strain added 10%sucrose,inoculated 5 mg/m L,fermentation time 3 days;The optimal conditions of2022+40827 combined fermentation were 8% sucrose,5 mg/m L inoculation and 5 d fermentation time.The optimal conditions of 2022+40864 combined fermentation were 6% sucrose,25 mg/m L inoculation and 4 d fermentation time.Under the above optimized conditions,the fermentation products of Aspergillus oryzae were prepared,and the components of the fermentation products were analyzed.Compared with the unfermented mung bean skin,the contents of total flavonoids and total phenols in the fermentation products were significantly increased,and the content of gallic acid was the most obvious.The content of insoluble dietary fiber in fermentation products was detected by alkali method,and the results showed that the fermentation products of 40827,2022+40827 and 2022+40864 meters of Aspergillus were 19.4%,31.7% and 32.4% higher than that of unfermented raw materials,respectively.Gc-ms was used to compare the changes of flavor substances in the fermentation products and mung bean skins.The results showed that the flavor substances in 40827,2022+40827,2022+40864 meters aspergillus fermentation products were mainly composed of alcohols,followed by hydrocarbons.Compared with unfermented raw materials,the relative content increased by 35.54%,43.09% and 31.21%,respectively.After aspergillus oryzae fermentation,compared with mung bean skin,the fermented products add mellow and curvilinear flavor,taste fresh and slightly sour.Response surface experiment was used to optimize the processing conditions of fermented beverage,which provided a technical basis for the further development of characteristic mung bean skin fermented beverage.