Nutritional quality of sunflower seed protein fraction extracted with isopropanol

This study investigated the nutritional effect of sunflower seed protein fr action (SSPF) extracted with isopropanol on growth, plasma and tissue lipid profile, protein content and erythrocyte membrane lipid profile of rats. D ehulled sunflower seeds were extracted with isopropanol at 50 +/- 1 degrees C resulting in a protein fraction (71.5%) with low residual chlorogenic ac id (0.07%) and fiber (3.3%) contents. Rats fed the sunflower seed protein f raction had a similar body weight gain and food efficiency ratios in compar ison to those fed casein. Rats fed SSPF in contrast had a significantly hig her growth and food efficiency ratio than the rats fed sunflower meal (SM), extracted with hexane. However, dietary proteins exerted a separate effect on plasma total cholesterol, low density lipoprotein (LDL)-cholesterol, lo w density lipoprotein to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio and triglyceride content. Sunflower seed protein fraction resulted i n a significant decrease in plasma cholesterol (p < 0.05) and LDL-cholester ol (p < 0.02) levels compared to the casein fed rats. Membrane phospholipid profile also showed a marked variation with the type of dietary protein. R ats fed SSPF and SM did not show much variation in plasma lipids, plasma pr oteins, liver and brain lipids and membrane phospholipid concentrations. Pr otein content, liver and brain lipid profile of the groups fed SSPF and cas ein were comparable, suggesting that the nutritional value of SSPF is bette r than SM and equivalent to that of casein.