Cereals as protein sources.

For at least 5000 years cereals have predominated as the arable crop grown to provide food for man and animals in the temperate climatic zones. They have been regarded as sources of energy and foods such as breads, spaghetti, chapattis, etc., require the addition of other protein sources to provide a satisfactory balanced diet. But cereals do contain significant amounts of protein, especially in diets formulated for animals and their modification in order to provide a ‘complete’ food would be advantageous, both economically in reducing expensive protein imports and also nutritionally in circumstances such as those obtaining in the developing countries where cereals already form too large a proportion of the diet. The fortification of cereal grains by the addition of supplementary lysine is one attempt at improvement and the arguments for and against this practice have been frequently stated. Selection of cereal strains has been practised from earliest times in order to increase yield. More recently attempts have been made to select for improved disease resistance and desirable characteristics such as strength and length of straw, and the ability to resist the premature shedding of ripe seed. Despite the suggestion that the selection of grains for improved protein quality is not of sufficient economic importance to justify the likely cost in terms of reduced yields (Aitken, 1968), the possibility of selecting for improved amino acid composition has not yet been ruled out. It is the purpose of this paper to examine some other possibilities for making the best use of cereal protein.