Study Of Production Technology And Quality Of Water Chestnut Wine

Brewing wine with water chestnut as raw material not only creates a new direction for the utilization of water chestnut resources,but also increases the diversity of fruit wine.In this thesis,by studying the main influencing factors in the process of water chestnut wine fermentation,clarification,aging and blending,the optimum brewing process parameters were determined.In addition,the quality and aroma components of water chestnut wine were analyzed.1.Pectinase can effectively improve the juice yield of water chestnut pulp.Based on the analysis of single factor and orthogonal test,the optimum enzymatic hydrolysis conditions were as follows:the addition amount of pectinase was 0.02 mg/g,the temperature was 35?,the time was 1.5 h.The yield of resultant water chestnut juice was 70.20%.2.The optimal liquefaction process parameters were determined,after single factor and orthogonal test analysis.The results were as follows:the addition amount of amylase was 18 U/g,the temperature was 95?,the p H value was 6.00,the time was 50 min.The optimum saccharification process parameters were as follows:the addition amount of glucoamylase was200 U/g,the temperature was 65?,the time was 2.5 h.After the process of liquefaction and saccharification,the content of reducing sugar in the water chestnut pulp reached 3.60 mg/m L.3.Six kinds of saccharomyces cerevisiae?DV10,71B,AWRI350,F33,F5,AWRI796?were used to brew water chestnut wine.Due to the fermentation performance with the highest alcohol content and sensory score,saccharomyces cerevisiae AWRI350 was choosed to make water chestnut wine.Water chestnut with peel,clear juice of water chestnut and peeled water chestnut were used as raw materials to ferment wine,respectively.And the results showed that the wine fermented by water chestnut with peel had the highest alcohol content,antioxidant property and sensory score.The single factor analysis and response surface optimization were used to determine the best fermentation process:the feed-water ratio was 1:2.5,the addition amount of SO₂ was 0.04 mg/g,the fermentation temperature was 28?,the fermentation sugar content was22.2°Brix,the p H value was 4.56,and the inoculation quantity of the yeast was 0.05%.After 7 d of fermentation under the optimal conditions,the alcohol content of water chestnut wine reached13.8%?v/v?and the sensory score was 85.0 points.4.Water chestnut wine was clarified by centrifugation,natural settling,cryo-preservation and clarifying agent respectively.And the results showed that gelatin had the best clarification effect.The best clarification conditions were:the addition amount of gelatin was 0.4 g/L,the clarification time was 60 h,the temperature was 30?.Under these conditions,the light transmittance of water chestnut wine reached 93.8%.After clarification,the stability study of water chestnut wine was conducted.The results showed that the light transmittance and chromaticity value were basically unchanged at low temperature,and the stability was good.But the wine was instable in the light.5.The effects of natural aging,ultrasonic aging and frozen aging on the quality of water chestnut wine were studied.The results showed that the effect of ultrasonic aging was the best.The optimal ultrasonic conditions were:the ultrasonic power was 50 W,the time was 15 min,the temperature was 50?.After ultrasonic aging for 45 d,the contents of total acid and total ester in water chestnut wine were 3.04 g/L and 2.33 g/L respectively.After aging,the wine blending process was optimized,and the best blending formulas were:the addition amount of sugar,citric acid and water chestnut juice were 15 g/L,0.5 g/L and 1.5%,respectively.Under this condition,the water chestnut wine had a sensory score of 95.0 points.6.Gas chromatography-mass spectrometry was used to analyze the aroma components of water chestnuts wine.The results were as follows:58,60 and 52 kinds of aroma components were detected respectively in the wine fermented by water chestnut clear juice,water chestnut with peel as well as water chestnut without peel.53,69 and 57 kinds of aroma components were detected respectively in the water chestnut wine clarified by centrifugation,gelatin and chitosan.68,74 and 62 kinds of aroma components were detected in the water chestnut wine of natural aging,ultrasonic aging,and frozen aging,respectively.Among them,ethyl acetate,isoamyl acetate,ethyl octanoate,ethyl caproate,phenethyl acetate,phenethyl alcohol,nonanal,and decanal were the main aroma components in water chestnut wine.