In vitro digestibility of rice and tapioca starch-based hydrogels produced by high-pressure processing (HPP)

The development of natural systems such as starch -based biopolymers and their applicability present a substantial challenge to the food industry, underscoring the critical need to extend the investigation to their digestibility. This study investigated the in vitro digestibility of rice and tapioca starch -based hydrogels, obtained by High -Pressure Processing (HPP) (600 MPa for 15 min) and by conventional thermal treatment (80 degrees C for 15 min) to assess the influence of HPP on starch digestibility as well as to identify the critical digestion steps. During in vitro digestion, disintegration, total hydrolysed starch, and starch nutritional fractions were determined. Results demonstrated that rice hydrogels underwent a higher disintegration extent and degree of starch hydrolysis with respect to tapioca hydrogels, being this more evident in HPP hydrogels. Both hydrogels were almost completely digested at the end of the digestion phases, with hydrolysed starch higher than 94% and 88% for rice and tapioca, respectively. HPP could represent a key technology to increase the digestibility of the resistant starch fraction of rice and tapioca starch hydrogels, increasing the potential applicability of these biopolymers.