探究模拟胃肠消化对蛹虫草蛋白质理化性质及抗氧化活性的影响。分别采用SDS-PAGE和酸水解法分析模拟胃肠消化前后的蛋白质分子量分布及氨基酸组成。通过体外化学评价方法，测定模拟胃肠消化前后蛹虫草蛋白质及其消化产物的抗氧化活性。构建H2O2诱导氧化损伤的PC12细胞模型，使用CCK-8试剂盒测定经蛹虫草蛋白质消化产物处理后细胞模型中的细胞活力。结果表明，经模拟胃肠消化后，蛋白质分子量的主要分布范围由10~120 ku变为8~15 ku；模拟胃肠消化前后DPPH自由基清除力的IC50值分别为1.55 mg/mL和1.06 mg/mL，Fe2+螯合力的IC50值分别为1.32 mg/mL和0.18 mg/mL，0.3 mg/mL样品的ORAC值分别为467.27±46.53 μmol TE/g和948.80±24.02 μmol TE/g；100 μg/mL消化产物预保护H2O2损伤的PC12细胞后，细胞活力显著提高（p<0.05）。蛹虫草蛋白质模拟胃肠消化前后均具有较强的抗脂质过氧化能力及较低的Fe3+还原能力。蛹虫草蛋白质经模拟胃肠消化后产生了更多小分子量多肽，抗氧化活性显著提高，因此可对消化产物中的抗氧化肽进行进一步的研究和开发。

Physicochemical properties and antioxidant activity of Cordyceps militaris proteins and their simulated gastrointestinal digestive products were investigated. Molecular weight distribution and amino acid composition of the proteins and digestive products were measured by SDS-PAGE and acid hydrolysis method, respectively. Antioxidant activity of Cordyceps militaris proteins and their simulated gastrointestinal digestive products was evaluated by in vitro chemical methods. Oxidative damaged PC12 cell model induced by H2O2 was established. After treatment with the digestive products, cell viability was measured by CCK-8. The results showed that after digestion, the molecular weight distribution shifted from 10~120 ku to 8~15 ku; the IC50 values of DPPH clearance rate of Cordyceps militaris proteins and their digestive products were 1.55 and 1.06 mg/mL, respectively. The IC50 values of Fe2+ chelating power were 1.32 and 0.18 mg/mL, respectively. The ORAC values were 467.27±46.53 and 948.80±24.02 μmol TE/g respectively when the sample concentration was at 0.3 mg/mL. The cell viability of PC12 cells injured by H2O2 was significant improved (p<0.05) after pre-treated with 100 μg/mL digestive products. Both of Cordyceps militaris proteins and their digestive products possess high lipid per-oxidation inhibition ability and low ferric reducing power. Thus, more peptides with lower molecular weight were generated after simulating gastrointestinal digestion of Cordyceps militaris proteins. Of note, the antioxidant activity improved significantly. It is therefore plausible to further purify and characterize the antioxidant peptides in simulated gastrointestinal digestive products of Cordyceps militaris proteins.

国家自然科学基金资助项目（31701195）；广州市科技计划项目（201604016068）；暨南大学111引智计划项目（50403053）