Chemistry of Shell Egg Deterioration: Effect of Reducing Agents

Abstract

INTRODUCTION THIS report is concerned with storage deterioration of eggs induced by exposure of fresh eggs to chemical reducing agents. Apparently few investigators have employed this method for reaching conclusions as to possible mechanisms by which deteriorations occur. Almost 50 years ago, Pollacci (1904) in Pavia, Italy, during studies of discoloration of egg yolk and white, observed that hydrogen sulfide caused thinning of white. Our interest was stimulated by a doctoral thesis (Hoover, 1940), representing earlier work conducted in this Bureau, in which it was reported that cysteine and thioglycolic acid caused thick egg white to become thin. Hoover suggested that the thinning might be due to reduction of the S—S bonds of the egg white protein, ovomucin. Hoover’s observations have been confirmed and, in addition, we have shown that other reducing agents cause thinning of egg white and that all of these reducing agents cause the yolk membrane . . .