消化对益生菌干酪抗氧化活性的影响

为探究益生菌干酪经模拟胃肠道消化后抗氧化活性的变化，本研究以1,1-二苯基-2-三硝基苯肼 （1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基清除率、还原力和2,2’-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐 （2,2’-azino-bis(3-ethylbenzthiozoline-6)-sulphonic acid，ABTS）自由基清除率为评价指标，同时研究添加双歧杆菌 （Bifidobacterium bifidum）07-300B、嗜酸乳杆菌（Lactobacillus acidophilus）1.0357的契达干酪消化前后的益生菌 活菌数及产生多肽的变化，从而明确消化对其抗氧化活性的影响。结果表明：干酪经消化后抗氧化活性显著增加 （P＜0.05），其中添加两种益生菌的干酪抗氧化指标显著高于其他组（P＜0.05），DPPH自由基清除率、还原 力、ABTS＋·清除率分别为（82.76±3.19）%、0.828±0.021、（44.84±1.36）%，较消化前分别增加了71.42%、 62.35%和51.69%；同时多肽质量浓度也显著增加（P＜0.05），达到（2.80±0.02）mg/mL，较消化前增加了 39.30%，其中分子质量小于3 kDa的多肽抗氧化活性最高；而益生菌活菌数显著降低（P＜0.05），相对于消化前降 低了16.93%。由此可知，模拟胃肠道消化后干酪抗氧化活性的提高主要与消化后产生具有抗氧化活性的小分子多肽 有关。

Antioxidant Capacity of Probiotic Cheese after Simulated Gastrointestinal Digestion

The aim of this work was to explore the effect of digestion on the antioxidant activity of probiotic cheese. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power and 2,2’-azino-bis(3- ethylbenzthiozoline-6)-sulphonic acid (ABTS) radical scavenging capacity were analyzed to investigate the antioxidant activity of probiotic Cheddar cheese after simulated gastrointestinal digestion, and the viable count of probiotics and polypeptide content were examined. The results showed that the antioxidant activity of cheese increased significantly after simulated gastrointestinal digestion (P < 0.05), and the antioxidant activity of cheese containing both B. bifidum 07-300B and L. acidophilus 1.0357 were significantly higher than that of any other group (P < 0.05). Moreover, the DPPH radical scavenging capacity, reducing power and ABTS+· scavenging capacity ((82.76 ± 3.19)%, 0.828 ± 0.021 and (44.84 ± 1.36)%) were increased by 71.42%, 62.35% and 51.69%, respectively, and the polypeptide content ((2.80 ± 0.02) mg/mL) was also significantly increased by 39.30% (P < 0.05) when compared with that before digestion, with the polypeptides with molecular weight < 3 kDa presenting the highest antioxidant activity. The number of viable probiotic bacteria in cheese decreased significantly by 16.93% after digestion. Therefore, the antioxidant activity of cheese could be improved by generating small molecule polypeptides with antioxidant activity after simulated gastrointestinal digestion.