Incorporation of fibre-rich and fat-rich ingredients as a tool to modulate starch digestibility of staple cereals

The rising cases of metabolic disorders like obesity and diabetes have boosted the demand for food industries to produce low glycaemic index products. The present investigation was undertaken to study the individual and synergistic effects of dietary fibre and fat in modulating the starch digestibility of wheat and rice, commonly consumed staples that elicits a high glycaemic index. Starch digestive profile, the kinetics of starch hydrolysis, and physicochemical properties were analysed. It was observed that incorporating fibre and fat significantly reduced the estimated glycaemic index by 11%, and the readily digestible starch fraction decreased by 40% in rice flour and 32% in wheat flour. Rice flour matrices substituted with fibre showed the lowest hydrolysis index (46.7), followed by matrices containing fat. Formulated composite mix was utilised to prepare fat and fibre-enriched Indian flat pan bread with reduced starch digestibility. The addition of fat and fibre altered the dough texture profile. The wheat-based composite mix dough had increased hardness and gumminess by approximately 42% and 50%, respectively. A four-fold increase in gumminess and hardness was observed in rice-based composite mix dough. However, the overall acceptability of the fat and fibre incorporated flat pan bread was higher by around five units, suggesting its acceptability.