Effect of ammonium oxalate and acetic acid at several extraction time and pH on some physicochemical properties of pectin from cocoa husks (Theobroma cacao)

Pectin was extracted from cocoa husk using two solvents (ammonium oxalate and acetic acid), extraction times (60 and 120 min) and pH (1.6, 2.6, 3.6 and 4.6). The pectin characteristics were yield, moisture content, ash content, equivalent weight, methoxyl, anhydrogalacturonic acid and degree of esterification. The result showed that the yield of pectin was 10.44 to 17.30%, the moisture content was 10.46 to 12.35%, ash was 8.45 to 12.93%, equivalent weight was 510.68 to 645.19, methoxyl was 4.62 to 6.01%, anhydrogalacturonic acid of 55.04 to 63.54% and the esterification degree of 45.26 to 55.31%. Ammonium oxalate was effective at pH 4.6, while the acetic acid was effective at pH 2.6 in pectin extraction. The extraction time for 120 min gave a higher yield compared to 60 min. Ammonium oxalate at pH 4.6 for 120 min has given the highest yield of pectin.