核桃饼粕多酚纯化工艺及其抗氧化活性的研究

研究大孔树脂纯化核桃饼粕多酚的工艺，比较AB-8、HPD-100、D101、X-5、NKA-9五种大孔树脂对核桃饼粕多酚的分离纯化效果。结果表明，HPD-100为分离纯化核桃饼粕多酚的最佳大孔树脂，其最佳纯化工艺为上样液pH值为4.0，质量浓度4.0 mg/mL，流速2 BV/h，体积1.8 BV，以体积分数为75%乙醇洗脱，洗脱流速4 BV/h，洗脱体积3 BV。用该工艺纯化后，核桃饼粕多酚的纯度从26.63%提高到81.10%，回收率为87.33%。纯化后的核桃饼粕多酚对1,1-二苯基-2-三硝基苯肼（DPPH）自由基、羟基自由基（·OH）、过氧化氢（H2O2）和超氧阴离子自由基（O-2·）清除作用均呈现量效关系，半数抑制浓度IC50分别为481.18 μg/mL、151.43 μg/mL、8.19 μg/mL和202.83 μg/mL，对DPPH和·OH清除能力较VC强，具有深入研究的价值。

Purification technology and antioxidant activity of polyphenols from walnut residue

Purification technology of walnut residue polyphenols was investigated using macroporous resin. The effects of macroporous resin AB-8, HPD-100, D101, X-5 and NKA-9 on purification of walnut residue polyphenols were studied respectively. Results indicated that the HPD-100 was the optimal resin, and the optimum purification conditions were sample pH 4.0, concentration 4.0 mg/ml, flow rate 2 BV/h, volume 1.8 BV, eluent 75% alcohol, elution flow rate 4 BV/h and elution volume 3 BV. Under these conditions, the purity of walnut residue polyphenols increased from 26.63% to 81.10% and the recovery was 87.33%. The purified polyphenols showed dose-dependent scavenging activity against hydroxyl (·OH), hydrogen peroxide (H2O2), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide anion free radical (O-2·), and its hemi-inhibiting concentrations (IC50) were 481.18 μg/ml, 151.43 μg/ml, 8.19 μg/ml and 202.83 μg/ml, respectively. Results showed that the scavenging activity against DPPH and ·OH of purified walnut residue polyphenols were stronger than VC, which was worth of further study.