H Study On Deacidification Of Plum Wine Using Ion-exchange Resin

Plum wine is rich in organic acids, such as citric and malic, etc.Normally, the content of citric acid and malic acid in plum wine is around 26.8g/L and 5.3g/L respectively, which is much higher than in other fruit wines. Meanwhile, the content of tartaric acid was much lower. Styrene, acetophenone, and 1-hexanol were identified as the main characteristic aroma substances in plum juice, and in plum wine, there were ethyl acetate, isobutyl alcohol, isoamyl alcohol, benzaldehyde and benzoic acid ethyl ester.Firstly, the type of ion-exchange resin was screened for plum wine deacidification. Results showed that the resin of type D314 was the best one. Following, the deacidification effect for both citric acid and malic acid by applying D314 resin were studied under static and dynamic conditions, respectively. It was demonstrated that the adsorption rate of total acids was increased with increasing of resin amount used. 50% total acids reduce can be obtained when the weight ratio of wine and resin was 10:1. The adsorption capacity was increased with adsorption time. Under stastic condition, the equilibrium between adsorption and desorption was reached at about 150 minutes. It was revealed that higher temperature has positive effect on enhancing adsorption. Meanwhile, considering the energy loss in industrial processing and the negative effects of high temperature on wine quality, the flow rate with 2BV/h and room temperature was chosed as the optimum resin exchange deacidification condition.With the increase of initial concentration of citric acid and malic acid, the adsorption effect of D314 resin became better. It was identified that the adsorption mechanism of organic acids in plum wine fit Freundlich model equation, which is spontaneous and endothermic procedure ( ? G < 0, ? H > 0, ? S > 0). It was calculated that the activation energy of D314 resin adsopting citric acid and malic acid was 10.429kJ/mol and 20.117kJ/mol, respectively, which indicates that citric acid was much easier to be adsorbed by resin.Finally, the effects of D314 resin adsorption on aroma of plum wine were studied as well. It was demonstrated that the content of furfural, which is harmful to wine quality, was reduced by 94% after the resin exchange process, while other aromatic components changed little. Therefore, it can be concluded that using D314 resin for deacdification adsorption could improve the quality of plum wine. Results of sensory evaluation showed that after being deacidifiacted by ion exchange, the total acid in pulm wine was significantly decreased, its taste and quality was decreased to some extent as well while still on acceptance range.Comparing with the side-effects of some chemical methods, such as neutralization process with bases, it was demonstrated that resin exchange was a feasible method for deacidification in plum wine industry.