Impact of hydrothermal treatment on functional properties of pearl millet flour: process modelling and optimisation

Hydrothermal process alters physicochemical characteristics of flour by fully or partially gelatinizing starch. Despite the recognized nutritional advantages of millet, the utilization of millet flour in food processing applications is limited because of its limited shelf life. By improving the functional properties, the utilization of millets in the development of innovative and gluten-free food products can be improved. This study aims to examine the effects of hydrothermal treatment on the modification of the functional characteristics of pearl millet flour. Water absorption capacity (WAC), oil absorption capacity (OAC), water solubility index (WSI), emulsion capacity (EC), and viscometric behaviour of pearl millet flour were studied under various soaking and steaming conditions and were found to be significantly affected by the process variables. The WAC and WSI decreased with soaking time but increased with soaking temperature and steaming time, whereas OAC showed the opposite trend for the same treatment parameters. The flour suspensions exhibited shear-thinning behaviour at all treatments within the domain. Further, the process parameters were modelled and optimised using RSM and ANN-GA techniques. The findings of this study will encourage the application of pearl millet flour in the development of various food products.