Effect of cations on heat degradation of chelator-soluble carrot pectin

The effects of monovalent salts, NaCl, KCl, and NH4Cl, and divalent salts, ZnCl2, CaCl2, SrCl2, CdCl2, and MgCl2, on heat degradation of pectin at pH 6·1 were examined. The β-eliminative degradation of extracted carrot pectin increased as cation concentration in the pectin solution was raised. At the same level of pectin methoxyl content, divalent cations promoted more depolymerization during the heating of pectin than did monovalent cations. The enhancement effect of cations on pectin degradation was greater for low-methoxyl pectin than for high-methoxyl pectin. The enhancement effect of cations increased in the order Zn++ > Ca++ > Cd++ ≈ Sr++ > Mg++ ≈ Na+ ≈ K+ > NH4+.