In vitro gastric digestion of cooked white and brown rice using a dynamic rat stomach model

Abstract

The changes in physical, rheological and enzyme-digestive behaviours of cooked white and brown rice, with similar amylose content, were investigated using a dynamic in vitro rat stomach (DIVRS) model and a static soaking method. The brown rice had a higher resistance on disintegration and lower gastric emptying rate with 53% of the brown rice particles retained in the stomach at the end compared to 32% for the white rice. Furthermore, the release rate of maltose from the starch hydrolysis was higher in the white rice throughout the digestion suggesting the lower glycemic potency of the brown rice. These differences could be contributed from the rigid bran layer in the brown rice which would inhibit the moisture absorption into rice kernels, limit textural degradation, and generate higher gastric digesta viscosity leading to lower mixing and mass transfer efficiency. This study suggests that the structural difference could affect physiochemical properties during gastric digestion.

Brown Rice Versus White Rice: Nutritional Quality, Potential Health Benefits, Development of Food Products, and Preservation Technologies

“…The BR showed a higher resistance to disintegration and lower gastric emptying rate compared to WR. In addition, the maltose releasing rate during starch hydrolysis was greater for WR than that for BR throughout the digestion (Wu, Deng et al., ). Furthermore, a study with human subjects showed a slower gastric emptying rate for BR compared to that for WR regardless of the variation in amylose content and in vitro starch digestion rates (Pletsch & Hamaker, ).…”

Effects of simulated gastric and intestinal digestion on chitooligosaccharides in two in vitro models

“…Protein in cooked meat was easier to decompose into peptides in intestinal digestion than in gastric digestion, and the size of peptides after gastrointestinal digestion ranged from 6 to 16 amino acids (Wen et al ., ), which could not limit the digestion process. Meanwhile, carbohydrates including rice were also easy to be digested and decomposed during digestive process (Chen et al ., ; Wu et al ., ). The digestion of both protein and carbohydrates contributed to the loose structure of food matrix.…”

Effects of the gastric juice injection pattern and contraction frequency on the digestibility of casein powder suspensions in an in vitro dynamic rat stomach made with a 3D printed model

“…It has also been used to study the role of rigid bran layer in contributing to the lower gastric digestion rate in cooked brown rice compared to that in white rice (Wu, Deng, Wu, Dhital, & Chen, 2017b). The gastric morphology and inner structure of the soft-elastic silicone rat stomach model have been proved to significantly impact the digestive efficiency of the casein powder suspensions (Chen et al, 2013).…”

“…The DIVRS-II is mainly composed of a 3D printing-based soft-elastic rat stomach model, a mechanical-electric driving device, a temperature-controlled box and a gastric secretion and emptying device. The fabrication and operation details have been previously reported (Wu et al, 2017b;Wu et al, 2017c). The fabrication details of the rat stomach models made by 3D printer are described as follows.…”

“…Previously, a 4.0 mm internal diameter PVC pipe linked to four small tubes (internal diameter 1.0 mm) was used to deliver the artificial stomach juice into the in vitro rat stomach model (Wu et al, 2014(Wu et al, , 2017b(Wu et al, , 2017c. At the time, we assumed that the simulate gastric juice from the PVC pipe would flow into the 4 small tubes reasonably equably.…”