The Effect of Dietary Pectin on Lipid Composition of Blood, Skeletal Muscle and Internal Organs of Rats

Abstract

The effects of dietary pectin on some blood indices and lipid composition of muscles, blood and internal organs were investigated in two experiments carried out with 51 male SPF White Wistar rats. One group of rats were fed ad libitum a diet containing 36.4% corn starch, 15.4% fats and 30.0% protein. Two other groups of rats had 4.8% (group P₁) or 9.6% (group P₂) of the starch in their diet replaced with pectin. Three months later, the rats were killed and hematological indices and lipid contents in various organs were investigated. Group P₂ rats had reduced body weight and reduced carcass fat; lower, but still within the normal limits, serum concentrations of total protein, albumin and α₁-globulin; lower concentrations of total lipids, cholesterol esters and triglycerides in their serum, liver and testes; lower percentage of oleic, linoleic and linolenic acids and higher arachidonic and stearic acids in lipids obtained from liver, heart, testes, kidneys, and skeletal muscles. Rats fed pectin used more and accumulated less triglyceride than the controls. No significant differences were found between control and group P₂ rats with respect to the nonestrified cholesterol and those phospholipids which form the structural elements of the cells. The increase in proportion of phospholipids to triglycerides in fat in the P₂ rats is suggested to be the main reason for changes in the composition of the fatty acids. The erythrocyte count, Hb and hematocrit were the same for both groups of rats. The control and P₂ rats consumed similar amounts of food having similar protein content. It is likely that the differences between control and P₂ rats were caused by an excessive accumulation of fat in the control. Swelling of pectin inside the intestines may be responsible for the fact that rats in group P₂ did not consume larger amounts of food though the food had a lower energy value.