New protein sources.

The question whether there is a real need for more protein is first critically reviewed and the two main ways of making more protein available are then exposed. They comprise the more efficient use of the protein already available and the synthesis of new protein. The possibilities offered by the oilseeds are then briefly expounded and the difficulties encountered in their practical application are evaluated. The texture meat-like products based on extruded soya and the more sophisticated spun fibers are mentioned. Protein synthesis using yeast, bacteria and algae as microorganisms is then described. The single-cell protein (SCP) products obtaine on different substrates (paraffins, alcohols or inorganic substrates) are evaluated as regards their general composition, amino acid content and nutritive value. The problems of wholesomeness and tolerance are briefly touched upon and the development of three generations of SCP products is envisaged, each having a higher degree of purity and being more suited as a food. Finally the prospects of SCP as human food are discussed.