Study On The Fermentation And Volatile Flavor Formation Mechanism Of Red Bean Corruption

The red bean corruption is a kind of sufu that has a long history of production techniques,with strong local characteristics.Under the trend of modernization of traditional foods,different strains had bean used to ferment red bean corruption,discussed the influences of the strains on propose fermentation and post-fermentation,and analyzed the characteristic aroma components and its formation mechanism.In order to establish a standardized red bean corruption manufacturing practices,and provide the scientific and theoretical basis of the formation mechanism of sufu.The activities of protease,glucoamylase and growth characteristics of strains were studied,and the results were as follows: Actinomucor elegans was the best strains in the single Mucor to ferment red bean corruption,The results showed that the Actinomucor elegans and Mucor racemosus was the best,and the ratio was 1:1.Rhizopus arrizus was more suitable for propose fermentation of red bean corruption.The better combination ratio of Rhizopus arrizus and Rhizopus chinensis was 7:3.The Actinomucor elegans and Rhizopus arrizus were more suitable for the fermentation of red bean corruption,and the optimum conditions were as follows: combination ratio 5:1,fermentation time 60 h,fermentation temperature 28 ℃.The changes of biochemical indexes and texture of red bean corruption during the post-fermentation were analyzed.And analyzed the red bean corruption by electronic nose,gas chromatography-mass spectrometry(GC-MS),and sensory evaluation.The changes of biochemical indexes and texture in red bean corruptions fermented by different strains were studied.Among them,the content of amino acid nitrogen and water soluble protein was higher in the red bean corruption fermented by Mocur,but the total acid content,pH value and salt content of red bean corruption fermented by Rhizopus were relatively high.Biochemical index can reach a high level of the Mucor and Rhizopus fermented red bean corruption.Hardness,springiness,cohesiveness,gumminess,chewiness of red bean corruption gradually reduced during the post-fermentation,while the adhesiveness gradually increased.Texture of Mucor and Rhizopus fermented red bean corruption is superior.The smell of red bean corruption fermented by different strains was different by principal components analysis(PCA)and linear discrimination analysis(LDA).The results showed that126 kinds of volatile flavor components were identified.The detected components in the samples were esters,alcohols,aldehydes,ketones,sulfur-containing ethers,heterocyclic components,acids,etc.The content of esters was the highest,and the volatile flavorcomponents is different among five kinds of red bean corruption.The sensory quality of red bean corruption fermented by Actinomucor elegans and Rhizopus arrizus is better.The characteristic aroma components in red bean corruption fermented by Actinomucor elegans and Rhizopus arrizus was analyzed by gas chromatography-olfactometry(GC-O).It showed that characteristic aroma components were composed by a variety of components including ethyl butyrate,3-(methylthio)propionaldehyde,isovaleric acid,benzaldehyde,phenol,ethyl caproate,ethyl caprylate,3,7-dimethylocta-1,6-dien-3-ol,phenethyl alcohol,indole.The volatile flavor components in the process of fermented bean corruption were tested.And 162 kinds of volatile flavor components were identified.The contents and kinds of the volatile flavor components increased during fermentation,especially in semifinshed product and salting pehtze.The total content of characteristic aroma components showed an increasing trend,and there were some differences in the components.The acid value increased,the peroxide value decreased and the content of reducing sugar increased.The acid value and reducing sugar are positively correlated with the characteristic aroma,while the peroxide value is negatively correlated.The total amino acid content decreased,the content of free amino acids increased,the free amino acids were positively correlated with the characteristic aroma components.