Extraction, structural characteristics and antioxidant activity of hemp seeds glycoprotein

The extraction process of hemp seeds glycoprotein (HGP) was optimized by using response surface methodology based on the single-factor experiments, and the structure characteristic and antioxidant activity of HGP were evaluated. The optimum conditions were extracting temperature of 58.54 °C, material–liquid ratio of 1:22.21 and ultrasonic power of 344.53 W. The molecular weight of HGP was identified by SDS-PAGE to be about 35 kDa. The FT-IR results demonstrated the presence of uronic acid and pyranose in the HGP structure. UV spectral scanning results confirmed the presence of a polypeptide skeleton structure and aromatic amino acids in HGP. TGA analysis revealed two weight loss intervals for HGP, with a thermal degradation temperature of 341.6 °C. Moreover, HGP demonstrated good antioxidant activity in vitro, with IC₅₀ values of all antioxidant indexes below 0.5 mg/mL. These findings provide a basis for in-depth exploration of functional characteristics of hemp seeds glycoprotein.