Chemical constituents and protein food processing of rapeseed

Abstract

In rapeseed, as in other oilseeds, there are some substances that adversely affect nutritional value. By application of appropriate technological processes, the antinutritive factors are removed and the final protein products appear to have high nutritive value. Compared with the soybean, rapeseed presents some unique problems. When processing rapeseed into protein foods, it is necessary to take into account high losses of nitrogen substances (nonprotein nitrogen), and higher costs of removing glucosinolates and their derivates, as well as phenolic compounds. Technically and economically feasible methods of reducing cellulose and phytate contents should be developed. In view of the presence of many constituents which lower the nutritional value of rapeseed protein products, it would appear that rapeseed is presently not a suitable raw material for production of food grade protein flour and grits. On the contrary, rapeseed protein concentrates and their texturates have satisfactory nutritional quality and feature good functional properties. Rapeseed isolates, except for poorer spinning properties, have similar characteristics to those of soybean isolates, but, as a result of low protein yields, their production is uneconomical. Recent progress in the breeding of glucosinolate-free and low fiber rapeseed varieties offers a new approach for development of processing methods for useful protein products based on this raw material.