INFLUENCE OF PARTICLE-SIZE AND SOURCES OF NONSTARCH POLYSACCHARIDES ON POSTPRANDIAL GLYCEMIA, INSULINEMIA AND TRIACYLGLYCEROLAEMIA IN PIGS AND STARCH DIGESTION IN-VITRO

Physico-chemical properties of dietary fibres might be involved in met abolic control, particularly of the postprandial blood glucose respons e. The aim of the present study was to look at the effects of the cont ent of soluble fibres and of the particle size of solid fibres on in v itro and in vivo starch hydrolysis and on the subsequent glucose absor ption as well as the triacylglycerolaemia. Two sources of dietary fibr es, one, with soluble fibres (beet pulp), the other with mostly insolu ble fibres (wheat bran), were added at the rate of 60 g/kg to a meal s imulating human food. The fibre sources were ground in order to obtain two different particle sizes (250 and 500 mum). Beet pulp decreased s ignificantly (P < 0.05) initial in vitro hydrolysis whereas wheat bran increased starch hydrolysis in the first 10 min. Wheat bran and beet pulp, whatever its particle size, lowered the post-prandial triacylgly cerol response. No significant effect was found with dietary fibre-sup plemented diets on postprandial glycaemic and insulinaemic values. Hig h correlation was found between initial in vitro starch hydrolysis and mean areas under the insulinaemic curves. This in vitro model can be used to predict initial in vivo digestion of carbohydrates from comple x foods.