Abstract
Experiments were performed to estimate the changes in the nutritional value of albumin accom panied with the oxidation of lipid in the system composed of egg albumin-ethyl linoleate (2 : 1, w/w, at 50°C and RH 80.4%).
Accompanied with oxidation of ethyl linoleate, browning of albumin occurred. The quantity of available lysine were decreased to one-half that of unreacted albumin at the day 7. There was a close correlation between the browning value and available lysine content (γ=-0.977). Solubility and digestibility in vitro by pepsin were also decreased. The contents of histidine, lysine, arginine and methionine in the reacted albumin were reduced.
The biological value and true digestibility of albumin which had been reacted with the oxidized linoleate for 7 days decreased significantly, the extent of which being approximately 20% and 10%, respectively, in comparison to those of unreacted albumin.
These damages of egg albumin accompanied with lipid oxidation were considerably more remarkable than those of casein, thus indicating much labile properties of albumin to oxidized lipid.
