Simple in vitro digestion device developed

15 Mar 2011

Jianshe Chen and co-workers from the University of Leeds, UK, have developed a simple model device for routine investigation of in vitro gastric digestion. Knowledge of food disintegration in the human stomach is essential for assessing the bioavailability of nutrients. Studies in medicine, pharmacy and clinical nutrition have demonstrated that disintegration of food and drugs inside the stomach is a highly complicated process. Food is broken down into small particulates and molecules as a result of both physical forces and chemical reactions; it is extremely difficult to mimic stomach conditions in vitro.

Although some very sophisticated in vitro digestion devices have been developed they are not suitable for routine use due to their complexity. In this study, the UK Food Scientists describe a simple in vitro digestion device. The device is housed in a water-jacketed glass vessel which has a constant flow around it to maintain body temperature. A spherical Teflon probe of variable diameter can be inserted which is controlled by a texture analyser and moved up and down to simulate the kinetics of a food digestion process. A schematic of the device is shown in the image to the right.

Under well controlled hydrodynamic flow and biochemical conditions this device can be used to determine key digestion parameters such as pH, food particle size, protein release, lipid release, cloudiness etc. Feasibility tests of the model device were conducted using roasted and non-roasted peanut particles; after digestion significant differences of surface microstructure were observed (see figure to left). The study also showed that parameters such as food to gastric juice ratio, probe speed and pepsin concentration all influenced the kinetic process of gastric digestion and need to be well regulated in any in vitro digestion investigation.