Abstract: [Objective] This study was conducted to optimize the glycosylation reaction conditions for flaxseed gum （FSG） and zein, and to characterize the structural and functional properties of the glycosylation product. [Method] Using grafting degree as the evaluation index, the main factors affecting the glycosylation reaction between FSG and zein were optimized by orthogonal test on the basis of one-way test. The structure of the FSG-zein glycosylation product was analyzed by the techniques of scanning electron microscope, Fourier infrared spectroscopy and endogenous fluorescence spectroscopy. Furthermore, the FSG-zein glycosylation product was functionally evaluated in terms of anti-oxidant capacity as well as emulsifying and foaming properties. [Result] The optimized glycosylation reaction conditions for FSG and zein were as follows: the ratio of zein solution to FSG solution was 1︰3, the pH value of the reaction system was 2, the reaction temperature was 90 ℃, and the reaction duration was 90 min. Under these conditions, the grafting degree of the FSG-zein glycosylation product was 77.81%. Scanning electron microscope, Fourier infrared spectroscopy and endogenous fluorescence spectroscopy analyses demonstrated that the initial structures of FSG and zein were significantly changed after the glycosylation reaction, confirming that FSG and zein generated FSG-zein glycosylation compound by glycosylation reaction. At a concentration of 1 mg/mL, the FSG-zein glycosylation product possessed a significantly （P<0.05） higher scavenging rate of ·OH than FSG, and exhibited significantly （P<0.05） elevated scavenging rate of DPPH and ABTS⁺ radical as well as total reducing power than FSG and zein. Significantly （P<0.05） increased emulsifying activity index and stability index as well as significantly （P<0.05） improved foaming ability and stability were observed in the FSG-zein glycosylation product in comparison to FSG and zein. [Conclusion] The glycosylation reaction conditions for FSG and zein were optimized, and the obtained glycosylation product possessed good anti-oxidant capacity as well as emulsifying and foaming abilities.

Key words: flaxseed gum, zein, glycosylation, grafting degree, anti-oxidation