Techno-Functional and Nutraceutical Assessment of Unprocessed and Germinated Amaranth Flours and Hydrolysates: Impact of the Reduction of Hydrolysis Time

Amaranth is a nutritional and naturally gluten-free pseudocereal with several food applications. The germination and pepsin/pancreatin hydrolysis in amaranth releases antioxidant and anti-inflammatory compounds but the hydrolysis times (270 or 360 min) are too long to scale up in the development of amaranth functional ingredients. The aim of this study was to estimate the influence of the germination and pepsin/pancreatin hydrolysis reduction time on the techno-functional properties and nutraceutical potential of amaranth flours and hydrolysates. The germination process increased 12.5% soluble protein (SP), 23.7% total phenolics (TPC), 259% water solubility, and 26% oil absorption in germinated amaranth flours (GAFs) compared to ungerminated amaranth flours (UAFs). The ungerminated (UAFH) and germinated (GAFH) amaranth hydrolysates showed values of degree of hydrolysis up to 50% with 150 min of sequential (pepsin + pancreatin) hydrolysis. The enzymatic hydrolysis released 1.5-fold SP and 14-fold TPC in both amaranth flours. The water solubility was higher in both hydrolysates than in their unhydrolyzed flour counterparts. The reduction in hydrolysis time did not significantly affect the nutraceutical potential of GAFH, enhancing its potential for further investigations. Finally, combining germination and enzymatic hydrolysis in amaranth enhances nutraceutical and techno-functional properties, increasing the seed. Consequently, GAF or GAFH could be used to elaborate on functional or gluten-free food products.