Abstract:

Deamidated wheat gluten was prepared via spray drying and freeze drying,and the structure as well asthe interfacial properties of the product was characterized by means of FT- IR,Raman spectroscopy and axisymmet-ric drop shape analysis.Then,the emulsifying and foaming properties of the gluten were analyzed.The results showthat (1) freeze drying helps to maintain the protein structure well; (2) the molecular vibration intensity changesafter deamidation; (3) freeze drying may result in greater structure unfolding of protein; (4) the samples obtainedby spray drying possess higher foaming and emulsifying ability but lower stability; and (5) deamidation helps toreduce the surface intension of gluten,and the samples obtained by spray drying are more effective in reducing thesurface tension but is of lower interfacial film elasticity,as compared with the samples obtained by freeze drying,which might be caused by the formation of insoluble protein that lowers the stability of the interfacial film.

Key words: deamidated wheat gluten, spray drying, freeze drying, structure, foaming property, emulsifying prop-erty, interfacial characteristic