The fibrous components of sugar beet pulp were investigated to determine whether they would reduce the post-prandial rise in blood glucose and plasma insulin levels when incorporated into a mixed meal. On two separate occasions six healthy volunteers were given either a control meal (providing 86 g carbohydrate) or an identical meal with the addition of 20 g sugar beet pulp (test meal). Blood glucose and plasma insulin levels were measured post-prandially for 3 hours. There was no significant difference between the mean blood glucose of plasma insulin curves at any time after the two meals. Since viscous types of dietary fibers are known to be effective in reducing post-prandial hyperglycaemia and insulinaemia, it would seem that either the physio-chemical nature of the fibre or the procedure employed to extract the sugar renders the particulate fibre inactive.

Guar gum from four industrial sources was investigated. The viscosity of two preparations of hydrated guar gum in the form of powdered flour and one granulate flour was measured at 22 degrees and 32 degrees C and pH 1.0 and pH 4.0. Viscosity measurements on wax-coated guar granules proved impossible but visual assessment indicated an extremely low viscosity in all conditions. These findings were compared with the ability of the equivalent of 5 g guar gum of the various preparations to modify the absorption of a 50 g liquid glucose load. The mean post-prandial blood glucose curve was not significantly different from the control situation after the incorporation of each preparation. Despite the granulate flour attaining a considerably lower viscosity than the powdered flour they were equally effective in significantly reducing the mean post-prandial insulin curve (area under the curve (0-180 min) reduced by 46 and 50% respectively). The wax-coated granules which achieved minimal viscosity caused significantly less reduction of post-prandial insulin levels (area under the curve reduced by 37%). The viscosity of guar gum upon hydration is of importance in assessing the efficacy of a preparation in clinical use.