Abstract: In order to investigate the interaction between gliadin from wheat and rutin under ultrasonic condition, the effect of ultrasonic power on the interaction between wheat gliadin and rutin was characterized by intrinsic fluorescence spectroscopy, synchronous fluorescence spectroscopy and ultraviolet (UV) absorption spectroscopy after 20-minute treatment with different ultrasonic powers (0, 150, 300, 450, and 600 W). The changes in the surface hydrophobicity, free sulfhydryl group content, thermal stability and microstructure of gliadin-rutin complex were determined. The results showed that the interaction between gliadin and rutin was affected by ultrasonic treatment. Besides, ultrasonic treatment increased the surface hydrophobicity and free sulfhydryl group content of the complex up to (37.00 ± 0.47) μg and (10.59 ± 0.42) μmol/g compared to the untreated control, respectively. The complex had better thermal stability than did gliadin when treated with the same ultrasonic power, and the treated complex exhibited a loose and porous microstructure. This study provides a new way for the functional and structural modification of gliadin from wheat.

Key words: wheat gliadin; rutin; ultrasound; interaction