Young male rats were fed with diets containing Hungarian soya products (extruded or granulated soya preparates) as the only source of protein for four weeks. The weight gain of the animals, the cholesterol and triglyceride content of liver and the activity of the hepatic monooxygenase system were studied. 20"; soya protcin in the diet (either from extruded or from granulated soya products) supplemented with sulphur cont:tining amino acids met the protein requirement of the young growing rats.
In a separate experiment the protein depletion-repletion method was used to investigate the effect of Purina 500 E soya protein isolate on the above mentioned parameters. The results indicate that diets containing 20°,, soya protein are satisfactory for the regeneration of the protein depleted animals.
Soya has been used for nutritive purposes in China for about 2500 years but the demand on soya products suitable for human consumption became world-wide only in the last 25--30 years [l, 91.
The wide use of soya is justified partly by its great nutritive value and partly by the favourable physical-chemical characteristics of its proteins (water-binding, emulsifying and gelforming capacity). According to SEAL [34], the main components of 100 g soya are as follows: 42 g protein. 20 g lipid, 6 g saccharose, 1 g raffinose, 3.5 g stachiose, 13.5 g unsoluble carbohydrate, 4 3 g ash. It contains furthermore a significant quantity of essential micro-' Dedicated to the 65th birthday of Prof. Dr. H. HAENEL.