Durian rinds were obtained from local fruits stall in Penang,Malaysia. Citrus pectin (CP) was purchased from Sigma; modified citrus pectin, MCP (PectaSol) was obtained from EcoNugenics;metal cations were used as their salts; Pb(NO3)2, NiCl2, CuSO4 were purchased from Sigma; ZnSO4 from Riedel-de-Haen, CdCl2 from Fluka. All other chemicals used were of analytical grade.