Acute glucose and insulin responses to cereal products based on a high β-glucan barley flour

OBJECTIVE: To assess postprandial blood glucose and insulin responses to cereal products made from barley flour enriched with β-glucans. DESIGN: a group of 10 healthy volunteers received, in random order and in different occasions, portions (40g of available carbohydrate) of 4 cereal products – whole-meal crackers (WMC) and biscuits (WMB), barley crackers (BC) and biscuits (BB)- and of white bread reference. Fasting and post-prandial venous blood glucose and insulin were evaluated for 90 and 180 min respectively after breakfast. RESULTS: whole meal products produced post-prandial glucose responses slightly lower but not significantly different from white bread reference. In contrast the two high β-glucans barley products, BC and BB, showed a low impact on postprandial metabolism, but only BB induced glucose responses significantly (p<0.001) lower than white bread reference and WMB. BB and BC showed flattened post-prandial insulin curves, lower either than white bread reference or than the corresponding whole-meal products. The glycemic indexes were 84, 92, 73 and 36 % for WMC, WMB, BC and BB respectively. Similarly the insulinemic indexes of barley products were lower than those of whole-meal products or that of white bread reference. CONCLUSIONS: “lente” products , with a discrete sensory quality can be prepared from barley flour enrched with β-glucans. The glycemic and insulinemic indexes of these products compare favourably with that of products made from common cereals , suggesting their use as “functional foods” in diet, either for individulal predisposed to metabolic disease either probably for patients with diabetes and hyperlipidemia.