Gastric secretion rate and protein concentration impact intragastric pH and protein hydrolysis during dynamic in vitro gastric digestion

Evaluation of the performance of the human gastric simulator using durum wheat-based foods of contrasting food structure

“…3D), but the pH value was higher than that of the remaining digesta. This trend aligned with a previous investigation on the digestion of protein dispersions in the HGS 51 and might be due to limited gastric mixing between SGF and the foods around the pyloric part of the stomach bag. Emptied pasta digesta always had significantly lower pH than that of semolina, possibly because of its lower buffering capacity 18 and the heterogeneity of the pasta meal that allowed the SGF to move more easily towards the distal part of the stomach bag to mix with pasta pieces.…”

“…Such approach did not account for the effect of buffering capacity of the foods on the initial gastric secretion rate and decreasing gastric secretion rate at longer digestion time, which have been reported to occur due to physiological responses. 18,69,70 An in vitro study using protein dispersions 51 reported that compared to using a constant SGF flow rate, reducing the SGF flow rate as the intragastric pH decreased resulted in a slower pH decrease in the HGS and consequently less protein hydrolysis. Similarly, a study using the HGS and in vivo-derived digestion parameters 71 reported a good agreement in the pH and moisture content with its related in vivo study, 29 due to the use of gradually decreasing gastric secretion rate as a function of digestion time (from 7.64 mL min −1 at 0 min to 0.764 mL min −1 at ≥120 min).…”

Inhibition of blood pressure elevation in GABA‐enriched Hidakakombu fermented with Lactiplantibacillus plantarum 002 protected addition of trehalose

“…Before meals, pH of gastric juice is 2–3. After meals, the pH fluctuates in response to the size, composition and physical state (liquid or solid) of the ingested food (Mennah‐Govela et al ., 2021). Ingestion during fasting may kill L. plantarum 002.…”

Comparison of four digestion protocols on the physical characteristics of gastric digesta from cooked couscous using the Human Gastric Simulator

“…There are at least two possible reasons for the difference in viscoelastic properties between in vitro and in vivo gastric digesta: (i) gastric secretions – the secretion rate in the in vivo condition depends on the gastric content, whereas in the in vitro conditions, a constant secretion rate was maintained by the peristaltic pump and was independent of the gastric content, and (ii) a variation in the digestion due to different pepsin concentrations between the in vitro digestion protocol and in vivo conditions. These imply the importance of accounting for the variable gastric secretion rate (which also affected the pepsin activity in the digestion system 59 ) when designing dynamic in vitro digestion protocols in future studies.…”