Incorporation of a novel leguminous ingredient into savoury biscuits reduces their starch digestibility: Implications for lowering the Glycaemic Index of cereal products

Abstract

Many carbohydrate foods contain starch that is rapidly digested and elicits a high Glycaemic Index. A legume ingredient (PulseON®) rich in Type 1 resistant starch (RS1) was recently developed; however, its potential as a functional ingredient when processed into a food product required assessment. PulseON® was used to replace 0, 25, 50, 75, and 100% of the wheat flour in a savoury biscuit recipe. In vitro starch digestion kinetics of biscuits and water-holding properties of ingredients were assessed. The RS1 in PulseON® did not appear to be structurally compromised during biscuit making. Replacing 50% wheat flour with PulseON® reduced the starch hydrolysis index of biscuits by nearly 60%. This seems to result from the ingredients’ impact on water availability for starch gelatinisation. Overall, these findings highlight the potential of using biscuits as a food vehicle for PulseON® to increase consumer intakes of legume protein, dietary fibre, and potentially low glycaemic starch. Keywords: Starch digestibility, Biscuit, Legume, Wheat, Composite flour, Resistant starch, Glycaemic Index, PulseON®