An in-vitro gastric digestion model with peristalsis function for the analysis of the food gastric digestion

In vitro models of the human stomach offer a robust platform to explore the physicochemical processes during gastric digestion. In Sri Lanka, limited research has been conducted on the digestion behavior of diverse food structures using in vitro digestion models. This study aims to create a custom-built in vitro gastric digestion model, specifically designed for Sri Lankan laboratories to analyze food digestion in a simulated stomach environment. The physical model comprises a butyl rubber chamber simulating the stomach, 4 nylon rollers with 2 rubber belts, driven by geared motors, and 6 nylon pulleys, creating continuous contractions of the rubber chamber. The model simulates the peristaltic movements of the stomach wall, with contraction waves occurring at a frequency of approximately 3 cycles per minute, mimicking in vivo peristaltic movement. Gastric sieving, secretion, emptying, and temperature control mechanisms are employed to recreate dynamic gastrointestinal conditions. A polyester mesh bag with a pore size of 1.5 mm replicates the gastric sieving function, while manual gastric emptying is performed. Gastric juice is secreted into the chamber at a rate of 2.5 mL/min using a programmed peristaltic pump, and an automated temperature control system maintains the ambient temperature at 37 °C. In conclusion, this developed gastric device serves as an effective tool for studying the gastric digestion of various food structures within a simulated stomach environment.