Abstract: Food gums, when used in soft-drink industry, was usually used in very low-concentration. In this paper, we studied the different contend of salt, alcohol, saccharose, starch or citric acid that would affect the viscosity of low-concentration food gum solutions. The results showed that with 0.25% guar gum, solution is more steady than that with 0.10% xanthan gum, 0.30% sodium alginate, or 0.10% agar. It was found that most metallic cations and anions could not affect the viscosity of guar gum solution, but they could obviously decrease the viscosity of agar, xanthan gum and sodium alginate solutions in the salt concentration from 10-4mol/L to 10-2mol/L. The viscosity of four kinds of food gums could all increase with the increase of concentration of alcohol. Saccharose could decrease the viscosity of 0.10% xanthan gum and 0.10% agar solutions, but when it mix of with 0.25% guar gum or 0.30% sodium alginate, it had the opposite effect. Citric acid could dramatically decrease the viscosity of 0.30% sodium alginate, 0.10% xanthan gum, or 0.10% agar solution, but it affected little guar gum.

Key words: Low-concentration Food gum Viscosity Salt Non-salt material