Pickled Eggs: 1. pH, Rate of Acid Penetration Into EGG Components and Bacteriological Analyses

Abstract

The white and yolk components of hard cooked eggs pickled in 3% or 5% acetic acid vinegars reached nearly equal pH values of 4.0–4.1 within six days after preparation. The pH declined rapidly in the egg white with a slower decrease occurring in the yolk. Maximal acetic acid concentrations were attained in the white in one day. Complete penetration of acid through the white to the yolk required 3 to 6 days to reach an equilibrium concentration and was dependent on the initial acid strength of the pickling solution. From day 6 to day 15, only slight changes in pH or acid concentration of the pickling solution, white or yolk were noted. Pickling spice ingredients reduced the initial acid strength of the pickling media (3% or 5%) by 20–23%. Bacteriological analyses of pickling solutions indicate that the pickled eggs were bacteriologically safe.