Heat-Induced Aggregation and Denaturation of Egg White Proteins in Acid Media

Authors

  • KENJI WATANABE,

    1. Authors Watanabe, Matsuda, and Nakamura are affiliated with the Dept. of Food Science & Technology, Faculty of Agriculture, Nagoya Univ., Chikusa-ku. Negova 464, Japan.
    Search for more papers by this author
  • TSUKASA MATSUDA,

    1. Authors Watanabe, Matsuda, and Nakamura are affiliated with the Dept. of Food Science & Technology, Faculty of Agriculture, Nagoya Univ., Chikusa-ku. Negova 464, Japan.
    Search for more papers by this author
  • RYO NAKAMURA

    1. Authors Watanabe, Matsuda, and Nakamura are affiliated with the Dept. of Food Science & Technology, Faculty of Agriculture, Nagoya Univ., Chikusa-ku. Negova 464, Japan.
    Search for more papers by this author

ABSTRACT

Heat-induced aggregation and denaturation of egg white proteins adjusted to pH 5.5, 4.5, 3.5 and 2.5 were investigated by vertical flat-sheet polyacrylamide gel electrophoretic and differential scanning calorimetric methods. The fractional and step-wise aggregation of egg white proteins was caused by heating. As the acidity was increased from pH 5.5 to 2.5, ovotransferrin, ovomacroglobulin, globulin G3A, globulins A1 and A2, and ovalbumin became much more unstable to heat. However, ovomucoid and ovoinhibitor did not aggregate in the acidified egg white under heat treatments of 3 min at 90°C or 20 min at 74°C. The heat-induced aggregation of flavoprotein was slightly greater at pH 4.5 and 3.5 than at pH 5.5 and 2.5.

Ancillary