Effect of high pressure soaking on water absorption, gelatinization, and biochemical properties of germinated and non-germinated foxtail millet grains

Abstract

Foxtail millet is one of the few crops that can thrive under relatively few agricultural inputs and have valuable amount of nutritional components. Therefore, processing of foxtail millet for value addition to various food products can significantly help in economic development as well as enhancing food and nutritional security. This study deals with the effect of high pressure soaking on water uptake, gelatinization characteristics, and nutritional and anti-nutritional properties of foxtail millet grains. The results demonstrated that high pressure soaking of germinated foxtail millet grains significantly increased the water uptake, thereby increasing the degree of starch gelatinization of the flour to attain a maximum value of 64.93%. The effective diffusion coefficient of water was found to increase with increasing pressures and temperatures, reaching maximum value of 6.77 × 10−9 m2s−1 for germinated foxtail millet grains treated at 200 MPa and 60 °C. For germinated foxtail millet grain flour, the total phenolic content and antioxidant activity (FRAP assay) improved significantly, although the protein content did not vary significantly. Further, the levels of anti-nutrients (phytic acid and tannin) decreased with high pressure soaking, which conclusively establishes that the quality of foxtail millet grains and its flour can be improved by using high pressure soaking.