[Biological value of fish protein isolates of the Marinbeef type]

Two samples of fish protein (made in Japan) obtained from fish of different fattness: walleye pollock ("arinbeef W") and sardine ("Marinbeef R") were studied. The biological value of these protein products was estimated with varying methods. In experimental rats fed with diets, containing the "Marinbeef" samples as the only source of protein (10% according to their calorific value), growth (PER and NPR) and balance (NPUtr) parameters of biological value, nitrogenous equilibrium (delta N +/- g/day) and actual assimilation (Dtr) of the proteins were assayed. The activities of aminopeptidase, creatine phosphokinase and the creatinine content were also studied in the rats' blood serum. The biological value of both "Marinbeef" products was found to be higher as compared to casein, and "Marinbeef W" values were higher than those of "Marinbeef R". No difference in the leucine amino-peptidase activity was revealed between the groups fed with different fish proteins, this activity being lower, while that of creatine phosphate higher as compared to the control group, although the difference was unauthentic (p greater than 0.05). The creatinine content did not differ from that in controls. "Marinbeef W" was assimilated better than "Marinbeef R".