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

Abstract

Previously, we have prepared a version of the dynamic in vitro rat stomach system (DIVRS-II or Biomimic Rat II). It was constructed and tested by showing similar digestive behaviors with those occurred in vivo. In the present work, a 3D-printed plastic mold was employed to create highly repeatable silicone rat stomach model. It has been seen to have shortened the time to handcraft a model like that used in DIVRS-II. The maximum mechanical force of the current stomach model generated by rolling extrusion is found to be more stable probably due to the more uniform wall thickness of the new model. Then the effects of the simulated gastric secretion patterns and contraction frequency of the system on the in vitro digestibility of casein powder suspensions were investigated. The results have shown that the location of the gastric secretion injection has an impact on experimental digestibility. The position of rolling-extrusion area, established at the central part of glandular portion (stomach B), displayed the highest digestibility compared to that at the other locations. Furthermore, the extent of digestion was positively correlated with the contraction frequency of the model stomach system, with the maximum frequency of 12cpm giving the highest digestibility. This highest digestibility is almost the same as the average value found in vivo. The better digestive performance produced by optimizing the gastric secretion pattern and contraction frequency may be both resulted from the improved mixing efficiency of the food matrix with digestive juice. This study shows that it is possible to achieve what in vivo in a simulated digestion device, which may be used for future food and nutrition studies in vitro.

Effect of lactic fermentation on soy protein digestive pattern assessed by an in vitro dynamic gastrointestinal digestion model and the influence on human faecal microbiota

“…The system has confirmed a good consistency with in vivo rat gastrointestinal digestion 7 . Several studies applied this model in evaluation of digestibility of soymilk, 8 rice, 7 casein protein 9 and bioactive substances 10 . Therefore, it is of great interest to investigate the effect of lactic fermentation on the fate of soy protein by the very system to determine a dynamic change in protein digestibility.…”

Physicochemical Properties and Digestion of Lotus Seed Starch under High-Pressure Homogenization

“…Starch samples (200 mg, dry basis) were dispersed in 2.0 mL of water and cooked for 15 min until gelatinized. Then 2.0 mL of artificial saliva (37 °C) was added to mimic oral digestion [16]. The food samples were digested in the DIVRSD-II model in batches as reported by Wu et al [15] for 0, 10, 20, 30, 40, 50, 60, 90, 120 and 180 min.…”

In vitro models to evaluate ingestible devices: Present status and current trends

“…This model was adapted to include a rolling extrusion motility pattern which improved the correlation between this in vitro model and in vivo data [163]. A further advance to this model was the use of a 3D printer to generate the silicon stomach structure which improved the uniformity of the wall thickness and hence the reproducibility in the motion applied [164]. This model would be suitable to assess the transit of devices through a rat stomach due to the considerable efforts made to replicate the anatomy and motility.…”