Study On The Fermentation Technology Of Jujube Dates Wine

Jujube dates were abundant in China and were very popular in people’s diet. The development of jujube dates wine could improve the economic value of the jujube dates, and had broad market prospcts and social benefits. In this paper, taking jujube dates as raw material, the variation of composition during jujube dates wine fermented by ten kinds of yeast and the relationship between the species and compositions were studied. The yeast of jujube dates wine brewing was selected and jujube dates wine fermentation technology was studied. The research results showed that:1、The content of reducing sugar, alcoholic, oxalic acid, malic acid, citric acid, succinic acid, caffeinic acid, chlorogenic acid and epicatechin of the jujube wine fermented by ten kinds of yeast were studied. The results showed that the content of alcohol including oxalic acid, malic acid, citric acid, succinic acid and caffeinic acid increased. The content of sugar, chlorogenic acid and epicatechin were decreased in the process of fermentation of jujube dates wine. The content of citric acid were 2.36 mg·mL-1. The content of oxalic acid including malic acid, succinic acid, chlorogenic acid, caffeic acid, epicatechin were less than 1.00 mg·mL-1. It could be use of the content of alcohol, citric acid and sensory evaluation to select strains. The content of alcohol of the jujube dates wine made by the 702 yeast up to 8.2% vol, the content of citric acid was 3.12 mg·mL-1 and the sensory score was the highest points. The jujube dates wine made by the yeast of 702 was better than others.2、The producing technology of fermentation wine with jujube was studied. Factors that had influence on the alcoholic fermentation were mainly considered, including inoculation amount, temperature, the initial pH value. The optimum process of jujube dates wine with the yeast of 702 was determined by orthogonal experiment. Jujube was added 0.2% prctinase,5 times of water and digested under the conditions of 40℃, initial pH value was 4.0 for 4 hours in order to get liquid extracts. The optimal fermentation conditions were decided as following: sulfur dioxide dosage was added 80 mg·L-1, yeast inoculation was 5%, jujube juice initial pH value was 4.0, fermentation temperature was 24℃ for 7 days. Then the wine was aged at 15～25℃ for 30 days. The dosage of 9% chitosan was the best clarifcation effect amoung the four agents, which luminousness reached the peak point of 92.94%. In these conditions, the alcoholic content of the product was 9.2%vol. Total acid was 4.9 g·L-1. Volatile acid was 0.26 g·L-1. Total sugar was 5.98 g-L"1. Dry extract was 25.82 g·L-1. Total sulfur dioxide was 25.6 g·L-1 and free sulfur dioxide was 12.8 g·L-1. The check indexes meet the national standards. The produced jujube dates wine was clarified in wine quality, having no sediments, and favors of jujube dates wine were heavy with favorable taste.