朝鲜蓟花苞汁总酚、总黄酮、抗氧化性比较及体外模拟胃肠消化特性

比较不同部位花苞汁及体外模拟胃肠消化前后总酚、总黄酮质量浓度，并通过总还原力和1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸阳离子自由基、超氧阴离子自由基清除率4 种方法评价其抗氧化能力。结果表明：花托汁总酚质量浓度为2.46 mg/mL，分别为内苞叶汁、外苞叶汁的1.13、1.94 倍；总黄酮质量浓度为6.53 mg/mL，分别为内苞叶汁、外苞叶汁的1.15、2.06 倍。在4 种抗氧化评价体系中，自由基清除能力强弱顺序均为花托汁＞内苞叶汁＞外苞叶汁，且自由基清除率均随着样品总酚质量浓度增加而增大。在体外模拟胃肠消化实验中，以花托汁为样品，经过模拟胃液处理后，模拟胃液组和胃酸对照组抗氧化性均显著增强（P＜0.05），但经过模拟肠液处理后抗氧化能力下降，表明胃蛋白酶、胃酸、胰蛋白酶均能促使抗氧化活性因子释放，提高抗氧化能力。

Total Phenols and Flavonoids and Antioxidant Activity of Artichoke (Cynara scolymus L.) Bud Juices before and after Gastrointestinal Digestion in Vitro

The contents of total phenols and flavonoids in artichoke bud juices prepared from receptacles and inner and outer bracts before and after gastrointestinal digestion in vitro were compared. Their antioxidant capacity was evaluated by four methods: total reducing power, and 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation and superoxide anion (O2-·) radical scavenging capacity. The results showed that the content of total phenols in receptacle juice was 2.46 mg/mL, which was 1.13 and 1.94 times higher than inner and outer bract juices, respectively. The content of total flavonoids in receptacle juice was 6.53 mg/mL, which was 1.15 and 2.06 folds increased relative to inner and outer bract juices. The antioxidant capacities of the three juices decreased in the following order: receptacle juice > inner bract juice > outer bract juice, and their radical scavenging capacity increased with phenolic concentration. After being treated with either simulated gastric juice or gastric acid, the antioxidant activity of receptacle juice was significantly enhanced (P < 0.05), whereas this was reversed by subsequent treatment with simulated intestinal juice. Therefore, pepsin, gastric acid, and trypsin could promote the release of antioxidant factors, thus improve antioxidant capacity.