Gelation properties of flaxseed gum

The gel formation and the effects of different factors on the gel strength of flaxseed gum gel were studied. The results showed that flaxseed gum could form thermoreversible cold-setting gel. Both gelling and melting points increased with increment in dissolution temperature. While at the same dissolution temperature, the gelling point was lower than its corresponding melting point. Because the gel strength dropped down with decreasing pH values at pH 2-6 or increasing pH values above pH 9, the maximum gel strength was obtained at pH 6-9. The addition of Na+ lowered the Zeta potential, thus decreasing the gel strength. But the effect of divalent cation Ca2+ on the gel strength was in two ways. Low concentration of CaCl2 (< 0.3%, w/w) increased the gel strength because of facilitating the formation of three-dimensional networks by Ca2+ cross-linking; but high concentration of CaCl2 (> 0.3%, w/w) had a negative effect by decreasing Zeta potential. Adding flaxseed gum to carrageenan gel decreased the syneresis of gel. (c) 2005 Elsevier Ltd. All rights reserved.