Study On The Technology Of Deacidification Of Kiwifruit Dry Wine

The high acidity in kiwifruit influence the quality of kiwifruit dry wine. Therefore, theaim of this study was to improve the quality of kiwi dry wine by reducing the total acids inkiwifruit dry wine. Firstly, the main organic acids of the kiwifruit and the liquor weredetermined by using chemical method, ion exchange resin method and microorganism methodrespectively. The main results were shown below:1. The organic acids in kiwifruit were analyzed with HPLC. The data showed that theorganic acids in kiwifruit were various. Lactic acid, oxalic acid, tartaric acid, malic acid, citricacid and succinic acid were detected as the main organic acids in kiwifruit. However, theircontens between the kiwi juice and wine showed little difference in variety. The content ofcitric acid which accounted for almost50%of the total acid is the highest among them.Meanwhile, because of the organic acids in the fruit wine are main from raw materialsthemselves rather than being produced in the fermentation process. The results showed thatthe organic acids of the kiwi fruit wine generally keep constant after fermentation.2. In the kiwifruit wine, after mixturing3.00g/L Na2CO3,1.2g/L K2CO3and4.0g/LC4H4O6K2into kiwi fruit wine, it made the general acid reduced to7.00g/L～8.00g/L,which reached the national standard. Besides, when6.0g/L C4H4O6K2was added, the winewas of best taste. When2.0g/L Na2CO3was added, the total cost was lowest, and the winewas also with good tastes and stability. Under the addtion of less than4.0g/L, and kiwifruitwine became transparency after reducing acid.3. Ion exchange resin method is suitable for reducing acids of kiwi fruit wine.In this study, the deacidification parameters of D314and914resins were optimized. Theoptimal parameters for D314resin were: D314resin volum was5mL, the loading quantity ofsample was100mL, the flow velocity was10mL/min. The results showed that the total acidof kiwi fruit wine was decreased to7.36g/L. Meanwhile, the optimal parameters for914resinwere:914resin volum was5mL, the loading quantity of sample was50mL, the flowvelocity was5mL/min. The total acid was found to be reduced to7.61g/L. It is concluded, theacidity of the kiwifruit wine that treated with the two resins both conforms with the nationalstandard. In comparison, D314resin has a better deacidification effect.4. In this study, the deacidification parameters of malolactic acid fermentation methodwere optimized. The optimal parameters were showed as follows: inoculation quantity of acidity yeast accountted for6%of the total fermented broth, the reaction temperature was24°C for6days, the initial pH was3.4. In this condition, the acidity of kiwifruit dry wine wasdecreased by16.17%. The taste was soft and harmonious.