Abstract: Extraction of protein isolates is one of main methods for further development and ultilization of wheat germ, while alcohol-maceration procedure is commonly adopted to improve the purity and colour of vegetable protein isolate products. Therefore the effects of alcohol-maceration procedure on the physicochemical, functional and structural properties of wheat germ protein isolates were studied in this study. The results of experiments showed that after alcohol-maceration procedure more than 80% of flavonoid compounds are removed, and the colour, purity and in vitro digestibility of wheat germ protein isolates are obviously improved. Furthermore, after alcohol-maceration procedure the solubility is sharply decreases, and water holding capacity, foaming capacity and emulsifying activity are also weakened, while fat holding capacity and emulsifying stability are slightly increase. In addition, after alcohol-maceration the secondary structure of protein isolates is changed, whereas α-helical and β-sheet structures are obviously increased, while β-turns and random coil structure decrease. So the secondary structure of wheat germ protein isolates becomes more tightly folded.

Key words:  , wheat germ； protein isolates； alcohol-maceration； flavonoid； physicochemical properties； functional properties； secondary structure；