Effects of Oil Thermally Processed with Vegetable Protein on Gastrointestinal Tract Content Transfer

It has been reported that oil heated with vegetable protein under reduced pressure, followed by filtration (soy oil), decreased body, liver and retroperitoneal fat tissue weights and serum triacylglycerol levels in Wistar rats. In order to clarify the mechanism of these weight-loss promoting effects, gastrointestinal tract content transfer was traced. Fasted 10-week-old rats were fed a slurry containing AIN93G without fat, Cr2O3 (marker), and 7 wt% soy oil or fresh oil (control) and sacrificed at 20, 60, 120, or 360 min; then, blood, stomach, small intestine, cecum, colon and feces were collected. The results indicated that the content transferred faster from stomach to small intestine in the soy oil group than in the control group. At 60 min after the ingestion of diet, an increased serum triacylglycerol level was found in the soy oil group. In addition, fecal excretion in the soy oil group was significantly higher 120 min after the administration than in the control group, suggesting that soy oil stimulated peristalsis of the colon and that colon contents (food ingested before administration) were actively excreted.