There was no significant effect on increasing the extraction time on the yield of pectin extracted using water, citric acid at pH 4.0 or hydrochloric acid at pH 2.5 or 4.0 (Table 1 ). This is in accordance with the study of Kalapathy and Proctor (2001) who studied the extraction of soy hull pectin using 0.1 N hydrochloric acid and found that longer extraction time do not affect the pectin yield. In water extraction of pectin, the medium lacks of hydronium ion to help solubilising other pectic materials which might not be water-soluble. The limiting factor would be the amount of water-soluble pectic material extractable regardless of the extraction time. The difference effect of time observed in extracted pectin
yield by citric acid pH 2.5 and pH 4.0 showed that the yield of pectin extracted by citric acid was dependent on the pH. This is in accordance with the study of Yapo (2009) that the yield of pectin from yellow passion fruit rind was greater when extracted at lower pH than at a higher pH using citric acid.