Abstract: In order to explore the relationship between emulsifying properties and structure changes, alkaline deamidation was chosen to modify zein. The results suggested that zein was more prone to deamidation in the alkali-water medium than various concentrations of ethanol aqueous solutions. The emulsifying activity and emulsion stability of zein with high deamidation degree (DD) (34.70%) were higher than those with low deamidation degree (0.89%) by 244.86% and 1 055.85%, respectively. The results of typical intrinsic emission fluorescence spectra and UV spectra indicated that the deamidation changed the conformation of zein, and the molecular flexibility was significantly correlated with conformation. The results of surface hydrophobic fluorescence spectrum showed that the deamidation reduced the surface hydrophobicity. The improvement of emulsifying properties could be attributed to the decrease of surface hydrophobicity and the increase of molecular flexibility of zein by deamidation treatment. It is hoped that this study could provide theoretical references for developing natural emulsifiers from zein.
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