HEAT-INDUCED EGG-WHITE GELS AS AFFECTED BY PH

The functional properties of heat-induced egg white gels were investig ated at five pH values. Textural characteristics were determined using the Instron Universal Machine. Hardness, elasticity, cohesiveness, ch ewiness, and fracturability were maximum at pH 11. Hunter L values wer e maximum at pH 5 and 7. Microstructure studied with electron microsco py was distinctly different at the five pH values. Alkaline gels showe d a fine ordered network that might have contributed to excellent text ural characteristics. Water-holding capacity (WHC) was high at alkalin e pH, but decreased with addition of 2-mercaptoethanol, suggesting tha t disulfide bonds were important in egg white gels. Sodium dodecyl sul fate (SDS) improved WHC at pH 7 and 9. No significant correlation was observed between textural profiles and WHC.