MODIFICATION OF FUNCTIONAL-PROPERTIES BY REARRANGEMENT OF DISULFIDE BONDS AND CHANGE OF RATIO OF PROTEIN-FRACTIONS

The growing use of different protein isolates (and concentrates) in fo od production in many cases requires modification of functional proper ties of isolates in order to assure the optimal physical (nutritional) properties of the endproduct. A number of possible nays of modificati on is known including chemical, physical procedures and also use of re combinant gene technology Such technologies are in many cases expensiv e and are connected with food safety problems. In search for relativel y cheap and safely process we studied the possibilities of applying re arrangement of disulfide bonds and change of ratio of protein fraction s. The models used in experiments were: gluten-, soy-, pea-, and wheat germ proteins. It was found that gluten polypeptide mixtures of same composition reoxydized under different conditions a ere transformed to protein masses of quite different functional properties. The same pro cedure resulted in only slight changes in the case of reduction and re oxydation of legume- and wheat germ proteins. The study of some protei n mixtures showed that the functional properties did not change linear ly with the composition of the mixture. In many cases maxima of some p arameters were observed.