Screening Of Fermentation Strains And Research On Fermentation Technology Of Whole-fruit Fermented Wine Of Red Tangerin

Wanzhou District is the one of the main planting areas with the largest area of tangerine,which are not only rich in nutritional value,but also have a bright color,sweet and sour taste,and are loved by people.At present,most of the citrus wine products on the market are processed with juice as raw material,and the processing of by-products such as peel,pomace and seeds in the process will cause a large amount of labor burden,and if the by-products are not properly processed,it will cause a waste of its resources and nutritional value.In this paper,a superior yeast strain was selected to ferment tangerine wine and optimize the fermentation process of tangerine whole fruit wine.Then the physicochemical indexes,antioxidant capacity and flavor of tangerine whole fruit wine,fruit pomace with juice wine and fruit pulp wine were compared comprehensively.The main research contents and results are as follows:1.Yeast was isolated from peel of tangerine,natural fermentation juice of tangerine and orchard soil from tangerine orchard in Dazhou Town,Wanzhou District,and through comparison of fermentation performance,a yeast strain with fast gas productivity,strong alcohol tolerance and high wine production capacity was selected and identified as S.cerevisiae.2.Optimization of tangerine whole fruit wine fermentation process with superior strain of S.cerevisiae,the optimal fermentation conditions were obtained by single-factor test and Box-Behnken method response surface design with yeast inoculum0.90×10⁷CFU·m L^-1,Brix°24.5%and fermentation temperature 26℃.The physicochemical indexes and antioxidant capacity of tangerine whole fruit wine,pomace with juice wine and juice wine were compared,and the alcohol,total sugar,reducing sugar,total acid,sensory score,total phenol and total flavone contents of tangerine whole fruit wine fermented under these conditions were 13.67%,9.78 g/L,4.03 g/L,5.72 g/L,81.47 points,1599.47 mg/L,863.68 mg/L,respectively.The total phenols,total ketones and antioxidant capacity of whole fruit wine were significantly higher than those of pomace with juice and juice wine.3.The volatile aroma substances of three different tangerine wines were detected by HS-SPME-GC-MS technique,and an OPLS-DA model was used to distinguish their flavor characteristics.Volatile fragrance components of 53,51 and 35 types were detected from the whole fruit wine,pomace with juice and juice wine,respectively,and the addition of peel enriched the alkenes of the whole fruit wine,mainly D-limonene.Through a weighted significant variable calculation and significant difference analysis,it was learned that aroma substances such as D-limonene,ethyl caprylate,isoamyl alcohol,2-methylbutanol,phenylethanol,linalool,α-pinoresinol,γ-pinoresinol,lauricene,and ethyl laurate were important variables to discriminate the flavor characteristics of tangerine wine from three different raw materials.4.The organic acid and amino acid contents of the three tangerine wines were analyzed and compared.the organic acid contents of the three tangerine wines ranged from 4339.6 to 6923.84μg/m L,malic acid,lactic acid,citric acid,and succinic acid were the main organic acids in the tangerine wines,oxalic acid,maleic acid,and fumaric acid were lower in the three tangerine wines.the amino acid contents of the three tangerine wines ranged from 39.51 to 138.49μg/m L,with the exception of isoleucine,a high variety and abundance of amino acids were detected in the whole fruit wine,and the content of proline,glutamic acid,and L-cysteine was higher;histidine was not detected in any of the three fermented wines.The contents of essential amino acids in whole fruit wine,pomace with juice wine,and juice wine were 18.47,13.09,and 9.63μg/m L,respectively,indicating that the addition of fruit peels enriched the content of essential amino acids.