| The mountain grapes in Mishan area of Heilongjiang have the characteristics of high sugar and low acid,and the organic acids in the mountain wine produced by it are mainly malic acid,tartaric acid,citric acid,oxalic acid,succinic acid and lactic acid.The high content of these organic acids and the unreasonable mass fraction will produce important shadow on the taste quality and stability of mountain wine.Therefore,deacidification is of great significance to the brewing of high quality mountain wine.The main purpose of this study is to reduce the organic acid content and change the proportion of the mountain wine according to the characteristics of the mountain wine and the characteristics of different methods of reducing acid,and to improve the sensory quality of mountain wine by chemical method and biological method.This study combines chemical and biological methods to reduce acid content in two kinds of grape wine.The effects of calcium carbonate addition,acid reduction ratio and temperature on chemical acid reduction of mountain wines were studied,and the chemical acid reduction process parameters of mountain wines were optimized.The effects of different acid reducing strains on acid reduction of mountain wines were studied,and the strains suitable for the biological reduction of acid in mountain wine were screened and the temperature and inoculation amount were studied.The effect of acid bacteria reducing sour grape wine can provide an effective way to improve the quality of malic acid and tartaric acid grape wine.Research shows:1.When the addition amount of calcium carbonate in the chemical deacidic acid wine is between 8 and 12 g/L,the total acid content in the mountain wine after deacidification decreases significantly and the pH increases significantly with the increase of calcium carbonate addition.Malic acid,tartaric acid and citric acid The contents of oxalic acid,succinic acid and acetic acid were significantly reduced,while the contents of lactic acid and acetic acid were not significantly reduced.After deacidification,the L value and a*value of mountain wine were significantly reduced.When the amount of calcium carbonate was 8 to 9 g/L,the b*value of mountain wine was not significantly reduced.When the amount of calcium carbonate was 10 to 12 g/L,mountain wine b*The value is significantly reduced.2.When the percentage of acid reduction of calcium carbonate from chemical reduction acid wine is between 60 and 100%,the total acid content of mountain wine decreases first and then does not change significantly after acid reduction.The pH increases first and then decreases,tartaric acid and citric acid.The contents of oxalic acid and oxalic acid were gradually reduced,and the contents of lactic acid and acetic acid were not significantly changed.When the ratio of reducing acid was 60 to 80%,the content of malic acid and succinic acid in mountain wines decreased gradually after acid reduction.When the acid reduction ratio was 90 to 100%,the content of acetic acid decreased.The content of malic acid and succinic acid increased.When the rate of acid reduction is 60?70%,the a*value of mountain wine is not significantly reduced;when the proportion of acid is reduced from 80 to 100%,the a*value of mountain wine is significantly reduced;when the ratio of acid reduction is 60 to 80%,mountain wine L The values and b*values did not decrease significantly.When the ratio of acid reduction was 90 to 100%,the L value and b*value of mountain wines were significantly reduced.3.When the temperature of acid reduction in mountain wine chemistry is between-5? and 20?,the total acid content in mountain wine increases gradually,the pH gradually decreases,and the malic acid,tartaric acid,succinic acid,and oxalic acid content gradually decrease as the acid-reducing temperature increases gradually.The acid content gradually increased.When the acid reduction temperature was-5?,the content of organic acids other than citric acid was the lowest in mountain wines after acid reduction.4.Through the box-Behnken experimental design of the response surface,the chemical parameters of acid reduction in mountain wine were optimized.The optimized conditions were verified as follows:the amount of calcium carbonate was 10.34 g/L,the ratio of acid reduction was 80.30%,and the temperature for acid reduction was-2.71 ?.The acid content of mountain wine after chemical deacidification was 11.72 g/L(as malic acid),pH was 3.53,malic acid content was 6.889 g/L,tartaric acid content was 0.567 g/L,and softness was 3.69.5.Through the use of three strains of different lactic acid bacteria to deacidify the mountain wines,the lactic acid acid-reducing lactic acid bacteria VP41 suitable for mountain wines was finally selected according to the malic acid conversion ability of the lactic acid bacteria and the sensory quality of the degraded mountain wine,and used as a strain for biological acid reduction.6.When the temperature of biological deacidification was between 14 and 30 ?,the total acid content of mountain wines gradually decreased,the pH increased gradually,the malic acid and citric acid content gradually decreased,and the lactic acid and acetic acid content increased gradually as the temperature of acid reduction increased.The sensory quality was better when the acid reduction temperature was 22 ?.7.When the inoculation amount of biological acid was between 0.05 and 0.25%(v/v),the total acid content of mountain wine gradually decreased as the inoculum size increased,the pH gradually increased,malic acid and citric acid content gradually decreased,and the content of lactic acid and acetic acid gradually decreased.increase.When the inoculation amount was 0.15%(v/v),the sensory quality was better. |
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