Investigation of the combination of legumes and cereals in the development of extrudate snacks and its effect on physico-chemical properties and in vitro starch digestion

The application of different levels of legumes in development of cereal-based extrudates has potential to produce healthy snack foods. The aim of this study was to investigate the effect of addition of legumes such as yellow pea, green pea, lentils and chickpea to wheat-, rice-, barley- and maize-based extrudates on its physical and nutritional properties. While legume fortification reduced the water absorption index (WAI) of barley-based extrudates, WAI was unaffected for wheat- and maize-based extrudates. On the contrary, type of legume influenced the water solubility index (WSI) of maize- and wheat-based extrudates. The results showed significant variation in final viscosity of the extrudates according to the levels of legume addition and cereal type. Particularly, in barley-based extrudates the final viscosity showed increase with addition of legume levels. However, the area under the curve (AUC) values for reducing sugars was reduced in legume-added samples compared to the control samples, the strongest decrease (p < 0.05) being observed in wheat + 5 % chickpea sample. The observed difference in viscosities shows possibilities of modification in physical properties and decreasing trend in AUC suggests the possibility for the production of low glycaemic extrudates through legume fortification.