Evaluation of guar biscuits for use in the management of diabetes: tests of physiological effects and palatability in non-diabetic volunteers.

A guar-shortbread biscuit has been successfully developed and tested for possible use in the dietary management of diabetes. A dose-response study was undertaken to estimate the amount of guar gum needed in the biscuit recipe to reduce postprandial glycaemia and insulinaemia. A control biscuit and three types of guar biscuit corresponding to a low, medium and high dose of guar (2.9, 6.0 and 9.1 g of guar respectively) were given to 8 non-diabetic subjects, and blood glucose and plasma insulin levels were determined at fasting, and at the postprandial times 30, 60, 90 and 120 min. Integrated insulin increments were estimated by calculation of the area under the curve. Sensory analysis of the biscuits was carried out by 36 non-diabetic panellists using a standard smiley chart containing hedonic phrases. No significant differences in the blood glucose increments were found between the control biscuit and the guar biscuits. However, all three guar biscuits produced smaller insulin rises than the control at all the postprandial times; statistically significant falls were indicated at the 60-min peak and 120-min times and for the integrated values. A linear regression model describing the relationship between integrated insulin and the dose of guar ingested is proposed. We have estimated from this model that a reduction of 209 mU/min/l in the integrated insulin can be achieved for every 1 g of guar incorporated into the biscuit. Mean hedonic scores indicated that all the guar biscuits were palatable, particularly the low-dose variety which was given a score almost identical to that of the control. A significant insulin-sparing effect in non-diabetic subjects was achieved using a palatable guar biscuit containing less than 3 g of guar flour.