Performance of Starch Gels on In Vitro Enzymatic Hydrolysis Assessed by Rheological Methodologies

Abstract

Starch hydrolysis is attracting much attention due to its relationship to digestion and glucose release. The objective is to propose rapid and continuous analytical methods that allow measuring gels hydrolysis following apparent viscosity (μ). Three different starches (corn, wheat, and rice) are tested recording starch gelatinization followed by gels digestions (digestograms) using a rapid-visco analyzer (RVA) or a rheometer. Results are compared with those obtained by measuring glucose release along hydrolysis. A modified first-order kinetic model in the RVA (R2 > 0.99) and rheometer (R2 > 0.99) describes the gels digestograms. Wheat gel shows a higher hydrolysis rate (k), which indicates faster digestion followed by rice and corn gels. The proposed models allow rapid analysis of starch digestograms, allowing to discriminate among hydrolysis rate of different starches. These less time-consuming methods can be an option to continuously analyze starch gelatinization followed by enzymatic digestion.