Nutritive value of acetylated and hydrolysed rapeseed proteins in rats

Acetylated, hydrolysed and unmodified rapeseed proteins were compared to casein for nutritive value as determined by net protein ratio (NPR) and nitrogen apparent digestibility coefficient (ADC). The NPR and nitrogen ADC values of rapeseed proteins did not change significantly (P less than 0.05) after hydrolysis but decreased significantly (P less than 0.05) after 30% and 70% acetylation. Acetylation (30%) followed by protein hydrolysis decreased significantly (P less than 0.05) the NPR value but increased significantly (P less than 0.05) the nitrogen digestibility compared to the control and unmodified rapeseed proteins. Casein gave the highest value (P less than 0.05) for NPR and nitrogen ADC. Modification of rapeseed proteins significantly (P less than 0.05) decreased the nutritive value, and the effect was more pronounced with increasing level of acetylation.