| Chaenomeles si nensis ( Thouin) Koehne was rose family plant of pawpaw category, shorting for pawpaw, it growing area was vast and output was great. The quality of pawpaw dry wine was influenced because of high acidity in pawpaw fruit. Thesefore,Shannxi baihe pawpaw was selected as the material of this research,in order to reduce acids of pawpaw dry wine to guiding the production of pawpaw dry wine,we used physical,chemical,lon exchange resin and microorganism methods separately based on the systematic analysis of organic acid sorts and contents of pawpaw and pawpaw juice. The main results were as follows:1.The organic acids components in Chaenomeles si nensis (Thouin) Koehne were analyzed by GC-MS and HPLC respectively. Experiment results with GC-MS showed that the organic acids in Chaenomeles si nensis (Thouin) Koehne were various and have high contents. There were 22 species totally in Chaenomeles si nensis (Thouin) Koehne. Among the whole contents the organic acids were account for 94.63%. The organic acids were mainly fatty acid, diprotic acid, ternary acid and little aromaticacid in Chaenomeles si nensis (Thouin) Koehne, among them the relative content of palmitic acid and 9, 12-Octadecadienoic acid (Z,Z)-(linoleic acid) reach to 39.87%. The relative content of diprotic acid-malic acid was 14.20%. Experiment results with HPLC showed that the malic acid in Chaenomeles si nensis (Thouin) Koehne was the most of all the seven acids, and reached to 29.72g/L. Among all the organic acids the malic acid accounted for 81.2%. By way of the analysis of constituents and contents of esterfing derivatives and educts in Chaenomeles si nensis (Thouin) Koehne by GC-MS, there were 33 species. There were more matters than the matters of Chaenomeles lagenaria (Loiscl) Koidz. These matters form the flavor and pHarmacological efficacy in Chaenomeles si nensis.(Thouin) Koehne.2.The pawpaw material dealing with hot burning reducing acids extent was great, the organic acids contents of pawpaw material reduced 36.1% from 3.56g/100g to 2.35g/100g, the malic acid reduced from 29.52g/L to 18.85g/L, the tartaric acid reduced from 5.28g/L to 4.27g/L, the citric acid reduced to 0.00g/L, the effective component oleanolic acid content of pawpaw has not remarkable difference. The general acid content of wine-making fluid dealing with hot burning was 7.33g/L, the acidity reached the national grape dry wine acidity standard, it had not remarkable influence on oleanolic acid. 3.In the pawpaw wine, after mixturing 1.0g/L calcium carbonate, 10g/L kalium of tartaric acid, 1.0g/L potassium carbonate and 8.0g/L kalium of tartaric acid all deacidifying reagent, it made the general acid reduced to between 7.00g/L～8.00g/L, and reached the national grape dry wine acidity standard. Thereinto, adding 10g/L kalium of tartaric acid reached the best taste, adding 1.0g/L calcium carbonate was the lowest cost.4.The optimal technic of 335 model resin deacidification were: resin quantity was 5 mL, the inpole quantity was 100 mL, the flow velocity was 10 mL/min, the citric acid was adsorbed completely, malic acid and tartaric acid reduced to 6819.12 mg/L and 323.22mg/L respectively, oleanolic acid reduced to 33.49mg/L. The optimal technic of D315 model resin deacidification were: resin quantity was 5 mL, the inpole quantity was 100mL, the flow velocity was 10 mL/min, when, the malic acid, tartaric acid, citric acid reduced to 7495.14 mg/L, 237.36 mg/L, 104.94 mg/L. The oleanolic acid reduced to 38.10mg/L. The pawpaw dry wine acidity reached the national grape dry wine acidity standard and D315 resin was the better resin of pawpaw dry wine deacidification.5.The best parameters of reducing acid process on pawpaw dry wine malic acid-lactic acid fermentation(MLF) were: the addition of lactic acid was 15mg/L, the addition of assisted leaven agent was 0.47g/L, the temperature of fermentation was 20℃, On this conditions, we got the pawpaw dry wine whose softness was 4.648. MLF went completely, the general acid decreased 25.82%, and reached the national acidity standard of raisin wine, The taste was soft and coordinated, Furthermore, the effective component of oleanolic acid in the wine wasn't affected.Through comparing with the four deacidifying methods, MLF deacidifying method was the optimal reducing acid method. |
