Study On Characteristics Indexes Of Fermented Vinegar Of Hanfu Apple

The Hanfu Apple was a new breed that Professor Li Huaiyu crossed the "Dongguang" apple with strong cold resistance and the delicious "Fuji" in the 1970 s.In recent years,with continuous improvement and rapid promotion and cultivation,its planting area and production have increased dramatically.However,most of the current sales channels of Hanfu Apples are fresh.There are few deep-processing,and the development is limited.Therefore,the analysis and identification of vinegar with cold-rich apples as raw materials is conducted to explore the quality of Hanfu Apple.It will lay a solid foundation for the promotion of Hanfu Apple fermented vinegar and abundant of Hanfu Apple industry chain.In this experiment,the sensory evaluation,physicochemical properties,and microbial indicators of Hanfu Apple fermented vinegar were adopted to study its safety,and the characteristic aroma components of Hanfu Apple vinegar were analyzed,and electronic tongue technology was adopted to analyze the taste of Hanfu Apple fermented vinegar.The main research contents and conclusions are as follows:Hanfu apple vinegar total acid content was 5.96g/100 mL,containing non-volatile acid 0.75g/100 mL,the reducing sugar based on glucose 1.23g/100 mL,and solid content 3.03g/100 mL,which was in compliance with national standards.When the antioxidant content of samples was determined,the polyphenol content index of Hanfu apple vinegar was 289.28±18.98 ug/mL;the flavonoid index was: 315.94±12.67 ug/mL,both of them were lower than Hanfu Apple cider and apple juice.The phenolic and flavonoid content of Hanfu apple vinegar is lower than that of grain vinegar.The total phenolic and flavonoid contents of apple cider vinegar beverages were 17.54 ± 5.77 ?g/mL and 32.54 ± 7.43 ?g/mL,respectively.The total phenolic and total flavonoid values of Hanfu Apple vinegar were 10 times that of apple cider vinegar beverages.The aroma component is one of the important indicators to evaluate the product quality.The solid-phase microextraction process was optimized by solid-phase microextraction-gas chromatography(SPME-GC).The best extraction conditions were: 1.5g of NaCl solids was added to vinegar,and the extraction temperature,time,and resolution time were set to 40° C.,30 min,and 3 min,respectively.The Hanfu Apple vinegar was extracted under these conditions to obtain aroma components including 15 kinds of carboxylic acids with relative contents of 48.5%,3.18% of alcohols,24.12% of ester materials,and 1.75 % of aldehydes and ketones are 6;3% of phenols are 4;7.48% of hydrocarbons are 9;5% of other substances are 6.From the comparison of Hanfu Apple fermented vinegar and apple cider vinegar beverages,Hanfu Apple has much higher levels of acetic acid and esters than apple cider vinegar drinks.There are 15 kinds of acids in Hanfu Apple vinegar,18 kinds of esters,and 7 kinds of apple vinegar drinks,5 kinds of esters.The aroma richness of apple vinegar drinks is not as good as apple fermented vinegar.Comparing with other vinegars of different raw materials,it is found that the aroma components in different substances are different,and the above differences can be used to distinguish vinegar products.Establishment of acetic acid,4-ethoxyethyl benzoate,geranyl isovalerate,3-methyl isovalerate,dimethyl phthalate,phenylethyl alcohol,1 in Hanfu apple fermented vinegar,3-butanediol is used as a characteristic index of aroma components.Based on electronic tongue,we detect the taste quality of vinegar.It was found that the acidity of the vinegar samples was the strongest,and that of the balsamic vinegar was the weakest.The balsamic vinegar has the strongest salty taste,while the apple vinegar drink has the weakest salty taste.The umami flavor of balsamic vinegar is the strongest,and apple vinegar drinks have the weakest flavor.Hanfu Apple vinegar has the weakest astringency,and the sourness and salty taste are in the medium level,but it has less bitterness and astringency and better taste.The e-tongue data was analyzed by principal component analysis and neural network method to analyze the differentiating effects of vinegar with different raw materials.Different methods were used to establish the prediction model,which had good repeatability and simple operation.