IMPROVEMENT OF PROTEIN GEL BY PHYSICAL AND ENZYMATIC TREATMENT

To improve the functional properties of food protein, physical and enz ymatic treatments are effective and attractive. As an example of physi cal treatment, heat treatment of egg protein under various conditions is shown. Egg albumin and egg white usually give turbid (white) gel on heating. However, we have learned that a transparent gel can be prepa red by regulating conditions of the medium. The molecular mechanism fo r formation of such gels and the physical properties of transparent an d turbid gels are shown. Proteolytic enzymes are often used to improve the properties of food protein, but sometimes bitter peptides are for med. Therefore, a limited proteolysis rather than nonspecific hydrolys is is preferable and effective in order to change the functional prope rties. We have shown that pepsin promotes limited proteolysis under pH control. Not only proteolytic enzyme, but other enzymes are also usef ul for improving food protein. Possibilities of the use of enzymes for food processing are shown here.