Study On Physicochemical Quality And Characteristic Flavor Of Musalais In Xinjiang

Musalais,as a traditional beverage of great antiquity,is abundantly characteristic of Xinjiang.Its unique raw materials and "three juicing" processing technology make it quite distinct from wine,and Making Musalais the flavor and quality is unique.It is of great significance to explore the characteristic aroma and physicochemical properties of Musalais for its production management and quality improvement.In this study,28 representative Musalais samples from Aksu area were used as materials to explore the differences in physicochemical quality and characteristic aroma of Musalais through the study on their physical and chemical indicators,sensory properties,aroma substances and non-volatile compounds.The main conclusions are as follows:1.The physical and chemical indicators including(methanol content,ethanol content,p H values,soluble solids content,color values,reducing sugar content,total sugar content,total acid content,sulfur dioxide content,etc.)of different Musalais samples were all meet the relevant standards;for the perspective of sensory quality,brown as the priority color tone of Musalais is embodied in the clear body,the taste of sourness and sweetness is balanced in medium bitterness following an astringent,round and long finish;fruity,mellow and baking aroma mainly Caramel are prominent,with medium floral aroma and light herbal flavor.2.The chemical constituents of Musalais were studied by the technology of UPLC-Q-TOF-MS,38 compounds were identified in total,including 8 furans,11 phenolic acids,14 flavonoids,and 5 other compounds.The changes of phenolic substances in the fermentation process were studied further in order to obtain the transformation law of phenolic substances.The results showed that the phenolic substances and antioxidant activity of concentrated juice were the highest,but the content decreased significantly as the fermentation process,and then gradually stabilized in the aging process.The brewing process had significant impact on the content and antioxidant activity of phenolic substances in Musalais.The concentration and fermentation technology could be optimized to improve the phenolic substances and antioxidant activity of Musalais,so as to improve the overall quality and texture of Musalais.3.GC-MS technology combined with aroma threshold analysis was used for the characteristic aroma compounds analysis.The results showed that a total of 13 compounds with average OAV ≥ 1 were identified.Further,two representative wine samples named M11 and M21,were further screened by PLSR analysis.Seven characteristic aroma compounds with FD≥2 and OVA≥1 were obtained by GC-O technology combined with multivariate statistical analysis.The characteristic aroma compounds were isoamyl alcohol,ethyl caproate,ethyl octanoate,furfural,5-methylfuranal,phenylethyl acetate and phenylethanol.To sum up,based on the present research on the quality characteristics of different Musalais,GC-MS,GC-O technology combined with aroma threshold analysis were used to clarify the characteristic aroma compounds of Musalais.Furthermore,the change laws of phenolic compounds and antioxidant activities in the key unit operations such as concentration,fermentation and aging.The present study provides an important theoretical basis for the quality management and production process optimization of Xinjiang Musalais.