2.3. Isolation of antioxidant peptides from GPH
2.3.1. Gel filtration chromatography
GPH solution (5.0 mL, 40.0 mg/mL) was added to a preequilibrated Sephadex G-15 column (1.6 × 70 cm) and eluted with distilled water at a flow rate of 1.0 mL/min. The elution was detected at 280 nm, and fractions were collected and the antioxidant activity was measured by scavenging activity of DPPH. The fraction exhibiting the highest activity was lyophilized,and subjected to next step of separation.