Effect of in vitro enzymatic digestion on antioxidant activity of coffee melanoidins and fractions.
Effect of in vitro enzymatic digestion on antioxidant activity of coffee melanoidins and fractions.
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DOI：
10.1021/jf0718291
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发表时间：
2007-10
影响因子：
6.1
通讯作者：
J. Rufián‐Henares;F. Morales
中科院分区：
文献类型：
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作者：
J. Rufián‐Henares;F. Morales
传统上，黑素的抗氧化活性只在食品的保质期内被评估，但胃肠道消化是必要的，以研究其潜在的生物活性。此外，在过去的十年里，人们一直强调类黑色素的生物命运，因为它们并不表现为惰性物质。本文以10 kDa截留膜超滤冲泡咖啡中的可溶性类黑素为原料，对其进行离子处理和酶促处理，分别收集高、低分子量组分。用五种描述良好的分析方法(DPPH、ABTS、ORAC、HOSC和FRAP)评估这些组分的抗氧化活性，这些分析方法预先设置在基于平板阅读器的自动化分析中。胃肠道消化后黑素释放出的低分子量化合物具有最高的抗氧化活性，甚至高于与黑素离子结合的化合物。胃肠道消化能够在一定程度上修饰咖啡黑素，这是从它们的绝对抗氧化活性推测的。有两个可行的选择：通过修饰/释放离子结合的化合物和/或通过在酶处理后从类黑蛋白骨架中产生新的更具活性的结构。
Traditionally antioxidant activity of melanoidins has only been evaluated in food for implication in shelf life but gastrointestinal digestion is necessary to study their potential bioactivity. In addition, the biological fate of melanoidins has been stressed during the past decade since they did not behave as inert substances. In the present paper a soluble coffee melanoidin isolated from brewed coffee after ultrafiltration with a 10 kDa cutoff membrane was treated ionically and enzymatically collecting the respective high and low molecular weight fractions. Antioxidant activity of these fractions was evaluated with five well-described assays (DPPH, ABTS, ORAC, HOSC, and FRAP) that were previously setup in a plate reader based automatized analysis. Low molecular weight compounds released from melanoidin after gastrointestinal digestion exerted the highest antioxidant activity, even higher than compounds bound ionically to melanoidins. Gastrointestinal digestion is able to modify coffee melanoidins to some extent, as hypothesized from their absolute antioxidant activities. Two options are plausible: by modifying/releasing the ionically bound compounds and/or by genesis of new more active structures from the melanoidin skeleton after enzymatic treatment.