葡萄酒泥中果胶的提取工艺优化与脱色

葡萄酒泥是葡萄酒在发酵、贮存期间产生的沉淀物,含有果胶、蛋白质、多酚等物质。为将酒泥中的有效成分分离提取,实现葡萄酒泥的增值利用,本研究以生产干白葡萄酒中的酒泥为原料,通过单因素实验探讨了料液比、pH、提取温度以及提取时间对果胶得率的影响,采用响应面法优化了果胶的提取工艺条件,并使用大孔树脂对果胶进行脱色,最后用红外光谱和HNMR进行结构表征。结果表明,在料液比(葡萄酒泥:水)为1:14 g/mL、pH为2.0、提取温度65℃、提取时间90 min时,果胶得率为6.48%,与响应面模型预测值6.50%相近,各因素对果胶得率的影响大小为:料液比>提取温度>提取时间>pH。选用D101大孔树脂对提取的果胶进行脱色,最佳脱色条件为脱色温度25℃、pH为2.0、脱色流速为3 BV/h,解吸液为60%(v/v)乙醇、解吸流速3 BV/h,在此条件下,脱色率可达91.75%。红外光谱和HNMR分析表明提取的果胶为α-半乳糖醛酸。研究为葡萄酒泥的成分分析和分离利用提供参考依据。

Optimization of Extraction Process and Decolorization of Pectin from Wine Mud

Wine mud is the precipitate produced during fermentation and storage, which contains pectin, protein, polyphenols and other substances. To realize the value-added utilization by separating and extracting the effective components of the mud in white wine production, in this study, the effects of material-liquid ratio, pH, extraction temperature and extraction time on the yield of pectin were investigated by the single-factor test, the extraction condition was optimized by the response surface method, the decolorization of pectin was carried out using macroporous resin, and the structure was characterized by infrared spectroscopy and HNMR. The results showed that the yield of pectin was 6.48% on the condition of wine mud:water=1:14 g/mL, pH was 2.0, extraction temperature was 65 ℃ and extraction time was 90 min, which was near to the predicted value of 6.50% by the response surface model. The factors on the yield followed as material-liquid ratio>extraction temperature>extraction time>pH. Decolorized by D101 macroporous resin under the condition that decolorization temperature was 25 ℃, pH was 2.0, decolorization flow rate was 3 BV/h and desorption solution was 60% (v/v) ethanol, desorption flow rate was 3 BV/h, the decolorization rate could reach 91.75%. IR and HNMR analysis showed that pectin extracted was α-galacturonic acid. This study would provide a reference for the separation and utilization of wine mud.