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

• Published in: Food research international Vol. 106; pp. 495 - 502
• Main Authors: Zhang, Xiaoai, Liao, Zhenkai, Wu, Peng, Chen, Liding, Chen, Xiao Dong
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.04.2018
• Subjects: 3D-printed rat stomach mold; Casein; Contraction frequency; Gastric secretion pattern; In vitro digestibility; Mechanical force; Contraction frequency; Mechanical force; In vitro digestibility; 3D-printed rat stomach mold; Gastric secretion pattern; Casein
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2017.12.082

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. [Display omitted] •Fabrication of the silicone rat stomach models using 3D printing technology.•In vitro digestion of the casein suspensions in the updated rat stomach system.•Comparison of casein digestibility between in vivo and in vitro rat stomach systems.•The gastric juice secretion pattern and contraction frequency affected the casein digestibility.•Similar digestive efficiency could be obtained in the updated rat stomach system with that in vivo.