IN SILICO AND IN VIVO VALIDATION OF DIGESTION BEHAVIOR OF RICE IN THE ARTIFICIAL STOMACH ARK®

Abstract

The effect of the physicochemical properties on the digestion behavior of rice was evaluated using the artificial stomach response kit (ARK®). Due to the presence of the external bran layer, brown rice (Rv3) showed delayed rates of gastric emptying, apart from a higher half emptying time (101.80 ± 1.20 min) than milled rice (Rv1 - 57.84 ± 7.49 min) and basmati rice (Rv2 - 77.93 ± 10.18 min). The bran layer of Rv3 inhibited the diffusion of the simulated gastric fluid and resulted in lesser particle breakdown and low glycemic index (GI). In comparison with the shaker digestion process, the mechanical force produced in the ARK® resulted in a higher degree of particle breakdown. An in silico approach successfully predicted the glucose response pattern of rice varieties with no statistical difference (at p< 0.05) with the human in vivo datasets using the output obtained from ARK®. The GI obtained from ARK® was validated with in vivo data using Bland Altmann’s statistical tool which showed good agreement. The morphology, dimensions, capacity of the stomach chamber in the ARK® also resembled in vivo observations. The ARK® is proposed as an improved alternative for in vitro digestion studies.