Nitrogen Solubility as a Means of Estimating the Gross Protein Value of Rapeseed Meal

INTRODUCTION STUDIES on the nutritive value of rapeseed meal have shown that different samples vary in quality according to variety of seed from which the meal is produced and the amount of heat used during expeller processing of the seed (Clandinin et at., 1959). Samples of high quality had amino acid patterns similar to that of soybean meal but those of lower quality were lower in lysine content (Clandinin, 1967). Since rapeseed meals may vary greatly in quality, the present study was undertaken to assess the validity of some laboratory tests of protein evaluation as compared to biological assay, in the hope that a simple physical technique could be used to correlate nitrogen solubility with protein quality in rapeseed meal. EXPERIMENTAL Ten samples of rapeseed meal (R.S.M.) were obtained from solvent, prepress-solvent and expeller processing plants. Some of the meals were prepared from B. campestris type rapeseed, while others were…