Effects of different cooking methods of oatmeal on preventing the diet-induced increase of cholesterol level in hypercholesterolemic rats

Background: The aim of present study is to investigate the influences of brewing and boiling on hypocholesterolemic effect of oatmeal in rats fed with a hypercholesterolemic diet. Methods: Fifty-six male Sprague-Dawley rats were divided into 5 groups of 8 rats each with similar mean body weights and serum cholesterol concentrations. Rats were fed with the experimental diets containing 10 % of oatmeal from two Chinese oat varieties which were brewed or boiled for 30 days. The lipids levels in serum, liver, and faeces were determined. Results: The effects of feeding boiled oatmeal on lowering lipid concentrations in plasma and liver were more significant than that of brewed oatmeal (P < 0.05). Feeding boiled oatmeal was also more efficient in increasing fecal total lipids, cholesterol and bile acids as compared to feeding brewed oatmeal (P < 0.05). Boiled oatmeal had higher apparent viscosity and soluble beta-glucan content than the brewed oatmeal did (P < 0.05). Conclusion: These results indicated that the capability of boiled oatmeal in improving cholesterol metabolism is better than that of brewed oatmeal, which is mainly attributed to its higher soluble beta-glucan content and apparent viscosity.