Effect of refining on the nutritional value of rapeseed oils for the chick and rat

Abstract

AbstractExperiments were conducted to examine the effect of refining upon the energy utilisation from high erucic acid rapeseed oil, low erucic acid rapeseed oil, maize oil, soya bean oil and herring oil.When fed to chicks and rats, refined high erucic acid rapeseed oils were markedly lower in m.e. and d.e. content and gave poorer growth and feed efficiency than the corresponding crude oils. Removal of the gums present in the crude oils was partially responsible for the reduction in the available energy of the oils. Alkali refining caused a further decrease while bleaching was the major step responsible for the reduced m.e. value for the chick. Low erucic acid rapeseed oil also showed a decrease in m.e. upon refining but the decrease was relatively small as compared with high erucic acid rapeseed oils. The refining of soya bean oil, maize oil and herring oil resulted in slight increases in m.e. and thus these oils responded quite differently to rapeseed oil upon refining.