The effect of solvent extraction upon the utilisation of rapeseed meal protein by rats

Untreated and formaldehyde‐treated rapeseed meals were subjected to a two‐stage extraction with aqueous and pure acetone. The extraction process significantly reduced the glucosinolate contents of the untreated and formaldehyde‐treated rapeseed meals on a proportional basis by approximately 0.85 and 0.75 respectively. The effect of both solvent extraction and formaldehyde‐treatment upon the utilisation of the rapeseed meal protein was determined using a rat bioassay. Formaldehyde‐treatment did not affect either the true digestibility or biological value of the rapeseed meal protein. However, solvent extraction whilst not affecting true digestibility increased the biological value of both untreated and formaldehyde‐treated rapeseed meals significantly by nearly 20%.