The effect of pH, ethanol volume and acid washing time on the yield of pectin extraction from peach pomace

An experimental study has been conducted to determine the effects of extraction time and pH variation on the yield of pectin isolation from pomace of peento peaches. Ethanol volume (EV) and pectin solution (extract) evaporation were defined to investigate their influence on the precipitation pH and the yield of pectic substances extraction. The yield rose as a result of the increase in initial pH, time of extraction and EV at pH less than 3.5. In contrast, further increase in pH resulted in a drop in the yield. The maximum yield of pectin extraction, 7.03% +/- 0.2%, was obtained at initial pH 2.5, EV of 1.5 and acid washing time of 120 min. In addition, the effect of EV on the degree of esterification (DE) and ash content of extracted pectic substances was determined by FTIR and ashing methods, respectively. Results indicated that EV can affect DE strongly.