wine mud, pectin, optimization of extraction process, macroporous resin, decolorization, structural characterization, Food processing and manufacture, TP368-456

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.