Gluten binds cytotoxic compounds generated in heated frying oil.

ABSTRACT

Male Wistar rats, age 10 weeks, were fed for 11 weeks a commercial powdered diet (no fat) containing 7 wt% fresh frying oil and 0.1 wt% gluten heated in oil at 180 degrees C for 10 h followed by filtration. The animals appeared to grow normally and had the same serum levels of glucose, triacylglycerol, phospholipids, and cholesterol as those of a control group fed a diet containing 7 wt% fresh oil. However, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly higher in the test group, and many dark-red patches due to bleeding were observed on the livers of this group. In contrast, rats fed for 11 weeks a diet containing 7 wt% of oil obtained by filtration after the heating described above did not show any damage to the liver or kidneys and showed no gross symptoms. Rats fed a diet containing 7 wt% fresh frying oil and 0.1 wt% gluten heated in a tube at 180 degrees C for 10 h did not show any differences from the control group. Analyses of low-molecular-weight compounds in the filtered oil revealed that gluten obviously reduced the level of all the low-molecular-weight compounds (except ethanol) of the oil heated at 180 degrees C for 10 h. Thus, it was suggested that gluten reacted with/adsorbed thermally oxidized oil/decomposition products and kept the cytotoxic low-molecular-weight compounds in the chemical structure even after filtration.