Efeito do tipo e concentração de óleos vegetais e de gordura animal sobre frações lípidicas do sangue e fígado de ratos

Abstract

Four lipid sources (soybean oil, canola oil, olive oil, swine fat) were studied aiming to establish iodine and saponifícation Índices as well as to verify the influence ofthe consumption ofthose hpid sources at two concentrations in the diet (7% and 14%), on some Hpid fractions in rats' blood and liver. Eight groups ofWistar rats were fed eigjit difíèrent diets containing the lipid and concentrate fractions reported for 56 days. TTie iodine and saponifícation índices were determined according to the AOAC (1990) and the animais' performance was evaluated through food intake, weight gain and coefficient of fèed efficiency (CFE). TTie dosages oftotal serum cholesterol and thriacylghcerols were performed by the colorimetric and enzyme method utilizing a commercial specific kit. The HDL cholesterol was determined by precipitation ofkilomicra, VLDL and LDL by utilizing also a specific kit. The total cholesterol and hepatic triacylglycerols were determined according to the method by Folch et ai (1957) and total lipids were done by ether extraction in Sohxlet apparatus. The values for iodine and saponfication Índices were respectively, 127 and 188 in soybean oil, 117 and 195 in that ofcanola and 73 and 190 in olive oil and 58 and 196 in swine fat. The animais fed 7% oflipid in the diet presented the lowest CFE. The increase of the concentratíon to 14% of lipids in the diet raised the total cholesterol contents, serum HDL cholesterol and LDL + VLDL cholesterol when the source was swine fat. Wrth 14% oflipid inthe diet, the lowest values ofserum triacylglycerols were found in the hpid sources soybean and canola oils with values of 76.09 and 84.42mg/dl, respectively. In both concentrations studied, the lowest values of total liver cholesterol were found in animais consuming soybean and canola based diets. TTie highest contents ofhepatic triacylglycerols were observed when ouve oil was utilized at both concentrations.