Cleaning beyond whey protein gels: Egg white
Résumé
There has been extensive research in the last decade trying to understand the fundamen-tals of dissolution of whey protein gels in order to lay the foundations of proteinaceouscleaning processes. To date, experimental data has been limited to whey proteins, raisingquestions of the applicability of the theoretical frameworks developed for whey proteinsto other protein systems. In this work the dissolution of crude egg white gels is studied,which are rich in ovalbumin protein, and which have recently shown a different cleaningbehavior to whey deposits. Egg white gels made in well-defined conditions were dissolvedin a wide range of alkali and sodium chloride concentrations, and temperature. The dis-solution rate was found to increase linearly with the alkali concentration up to 1 M, henceconfirming the absence of an optimum cleaning concentration observed in whey proteincleaning studies. The apparent activation energy of dissolution for particulate egg whitegels was 70–80 kJ mol−1, suggesting that the dissolution of egg white gels is controlled bythe -elimination of disulfide bonds. Dissolution experiments with salts at different tem-peratures confirmed that swelling is very important in the dissolution of whey protein gels,but not in egg white gels.