Effect of using alternative flours on the development and characteristics of a third-generation snacks

Abstract

The effects of black bean addition (11, 22, and 33%) to a base mixture of blue corn and powdered spinach were evaluated during the combined process of extrusion cooking and microwaves to obtain a third-generation snack. The expansion index (EI), hardness, water absorption index (WAI), water solubility index (WSI), bulk density (BD), functional properties (total anthocyanin content [TAC], total polyphenol content [TPC], and antioxidant activity [AA]), and nutritional properties (in vitro protein digestibility [IVPD] and protein bioaccessibility [IVPB]) were evaluated. Additionally, X-ray, FT-IR, and microstructural analyzes were conducted to evaluate the structural changes in the extruded and expanded products. A 33 % of black bean addition led to significant (p < 0.05) increases in protein and fiber content, generating increases in hardness, WSI, TAC, BD, IVPV, and IVPB and decreases in EI, TPC, AA, and WAI of final extrudates. Microstructural changes occurred after processing, showing structural damage to the native starch and presenting changes in the type V diffraction pattern and protein denaturation. The extrusion process was adequate to increase the IVPD and IVPB to above 90% and generate high levels of amino acids such as histidine, glutamic acid, glycine, phenylalanine-tyrosine, and leucine, which could generate bioactive peptides.