The effect of pH on the network structure of the capsules made from 1.0%(w/v) chitosan and 1.0%(w/v) xanthan solutions is shown in Fig.3. Both transitions from xanthan gum and chitosan observed at pH 4.5 were eliminated when the pH was increased to 6.2. This result might suggest an incomplete crosslinking between the two polymers at pH 4.5 and a complete crosslinking at pH 6.2.The swelling data also show that there is a significant decrease in the degree of swelling when pH is increased from 4:5 (SD ¼ 2164) to 6:2 (SD = 1187), which can be explained by the increase in the crosslinking density.