The Absorption by Immature and Adult Rats of Amino Acids from Raw and Autoclaved Fresh Pork

Abstract

Fifteen amino acids have been determined by quantitative paper chromatography of their dinitrophenyl derivatives in plasma of portal blood taken from immature male and from adult male and female rats at various time intervals after feeding them raw or severely autocleaved fresh pork. Rats fed the raw pork exhibited a prompt increase of free amino acids in plasma from portal blood. The highest values of the absorption curve were at three-fourths hour after feeding in the adult males, and, except for glycine, at one-half hour in the adult females. Only the one-half hour time interval was studied with the young rats, after which those fed raw pork showed an increase of 101 to 340% for all amino acids studied. The adult animals had rises of 48 to 294% at the peak of absorption after ingestion of the raw meat. Both young and adult rats fed severely autocleaved pork showed much smaller increases, -33 to 95%, and in the adult rats the highest values for the different amino acids were scattered over the whole time up to and including 5 hours, the last time interval studied. The results are interpreted as supporting the theory that decreases in biological value caused by overheating proteins are at least in part due to failure of digestive enzymes to hydrolyze the overheated proteins so as to make available simultaneously to the animal an assortment of amino acids favorable to good growth or maintenance.