Antinutritional and toxic effects in albino rats of rapeseed protein products added to standard diet

ABSTRACT

Flour and protein concentrate of two rapeseed varieties were prepared and used at a level of 50% of total protein in synthetic diets containing 15.4% protein. The feed consumption [FC] and protein retained by the albino male rats fed the concentrate diets were significantly higher than those of flour diets and insignificantly differed from a casein control diet. The partial composition of rat bodies at 2,4 and 6 weeks of age showed slight differences in dry matter and protein percentage between rats fed casein and concentrate diets. Highest protein efficiency ratio [PER] and biological value [BV] were found for rats fed Brassica campestris diets. Whereas, the highest NPU was found for rats fed casein or Brassica napus diets. Also, there was a positive relationship between PER and BV, and negative with each of PER or BV and NPU. The proteins concentrate diets had no significant effect on relative liver weight, whereas flour diets caused significant enlargement of the liver. The macroscopic examination indicated that the increase of liver weight of rats was paralleled with hemorrhage incidence. The concentration of low density cholesterol and triglycerides, GOT and GPT enzymes activity were significantly decreased in rats blood fed concentrates, while albumin concentration was only slightly affected. Histological examination of liver and heart of rats indicated lower negative effects of rape protein concentrates comparing to the effects of rape flour. The above findings indicated clearly that processing rape flour to rape concentrates reduced the toxic and antinutritional components but did not eliminate them