HEAT-INDUCED GEL PROPERTIES OF FREEZE-CONCENTRATED EGG-WHITE PRODUCED USING BACTERIAL ICE NUCLEI

This work proposes a new method for improving the functional properties of food proteins by intentional modification. Hen’s egg white wits used as an example of the food proteins to be improved. Commercially available egg white was freeze-concentrated using bacterial ice nuclei. The resulting increase in its solid content led to formation of a hard, but fragile gel by heat treatment at 90-120°C for 20 min. When modified with arginine, it was changed to a viscoelastic product. Scanning electron microscopic and pulsed NMR observations suggested that tight aggregation of constituent protein molecules occurred in the hard gel network by the heat treatment and that the aggregation partly became loose by the modification with arginine. © 1990 by the Japan Society for Bioscience, Biotechnology, and Agrochemistry.