PL
Zbadano wpływ sterylizacji na wartość odżywczą dwóch gatunków białka: mleka (kazeiny) i ryb (dorsza). Metodą chemiczną i biologiczną (strawność, przyswajalność i wydajność wzrostowa), określono poziom dostępnej metioniny i cysteiny w wątrobie i moczu zwierząt doświadczalnych.
EN
The sterilization effect was analysed on the nutritional value of two protein types (mik/casein) and fish (cod). By chemical-biological method (determination of digestibility, assimilability and growth yield) the level of accessible methionine and cysteine, and taurine level as a metabolite of sulphur-containing amino acids were determined in the liver and urine of experimental animals. Cod protein and casein subjected to technological processing showed lower digestibility, assimilability and growth yield as compared with raw protein. The serum level of biologically active sulphur-containing amino acids methionine and cysteine was lower also. A significant correlation was found between the results of the biological assessment of the nutritional value of protein, and the levels of methionine and cysteine in diet on the one hand, and the content of taurine in the liver and urine of rats, on the other hand. The possibility of assessment of the nutritional value of protein based on urinary taurine level is a simple and non-invasive method based on teh metabolism of sulphur-containing amino acids in the organism of humans and animals which encourages for further tudies.