Germinated chickpea-maize extrudates with high protein content and reduced starch digestibility

The objective of this study was to produce maize extrudates supplemented with germinated chickpea flour to increase the contents of resistant starch (RS) and protein. Six extrudates were formulated using maize grits (ME), germinated chickpea flour (GCE) and different blends of maize and 10%, 20%, 30%, or 40% of germinated chickpea flour (MGCE-10, MGCE-20, MGCE-30, or MGCE-40). Increase of RS was observed in the defatted samples due to germinated chickpea flour addition. In the nondefatted samples, the highest content of RS was observed in GCE followed by ME and the different MGCE. Interaction between fat, starch, and protein by improved intramolecular association was assessed by Fourier transform- infrared spectroscopy (FTIR). Amylose-lipid complexes in nondefatted samples increased the content of RS in comparison to defatted samples. The highest expansion index was obtained in MGCE-30 and MGCE-40. ME had the highest hardness and crispiness. Germinated chickpea flour increased the water absorption index (WAI), but reduced water solubility index (WSI) when it was combined with maize grits to produce extrudates. The in vitro protein digestibility (IVPD) was higher in the GCE and MGCE with more than 20% of germinated chickpea flour compared to ME. MGCE-20 and MGCE-30 showed the highest acceptability of the supplemented extrudates with 50% more protein than ME, a similar IVPD to that of GCE, and good functional characteristics. PRACTICAL APPLICATION: Combining maize and germinated chickpea flour is a good strategy to have a controlled digestibility of starch and increase the plant based protein content in healthier snacks.