Rodríguez Mariela, Tironi Valeria A
Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA) - (CCT La Plata-CONICET, CICPBA, UNLP), 47 y 116 (1900) La Plata, Argentina.
Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA) - (CCT La Plata-CONICET, CICPBA, UNLP), 47 y 116 (1900) La Plata, Argentina.
Food Res Int. 2020 Nov;137:109524. doi: 10.1016/j.foodres.2020.109524. Epub 2020 Jul 21.
In this work, there were analysed the interaction between phenolics present in amaranth flour (F) and amaranth protein isolate (I) with other components, as well as the effect of the gastrointestinal digestion on them (Fd and Id). Extractions were performed under different conditions (temperature, acid, organic solvent, alkali). Methanol/water extracts (25 °C and 80 °C) from F showed the presence of isoquercetin/rutin, quercetin, kaempferol and two unidentified peaks (II and III). In the presence of acid (much more evident at 80 °C), the extraction of some components increased: catechin, 4-hydroxibenzoic acid, isoquercetin/rutin, II, III. When methanol/acetone/water extraction was performed, p-coumaric acid and a new unidentified peak (IV) were observed. About 15% of the total phenol -namely; p-coumaric, rutin/isoquercetin, and kaempferol- were linked to the protein fraction. After the proteins were isolated (I), the amount of some of the compounds which were originally present in a soluble form (e. g. catechin) and in the protein-bound fraction were decreased. Simulated gastrointestinal digestion of flour released some phenolics (catechin, phenolic acids) that were ligated to proteins, and they significantly incremented the ORAC and ABTS activity of most of the extracts. Isoquercetin/rutin, quercetin and kaempferol remained after digestion. Extracts from the digested protein isolate presented differences in the composition and lower ORAC and/or ABTS activities for some of them. The study of the effect of the simulated gastrointestinal digestion process on bioaccessibility and on antioxidant activity (an aspect that, to our knowledge, has not been previously studied on amaranth polyphenols) yielded promising results, which suggest that amaranth flour is a potential antioxidant functional ingredient.
在本研究中，分析了苋菜粉（F）和苋菜分离蛋白（I）中酚类物质与其他成分之间的相互作用，以及胃肠道消化对它们（Fd和Id）的影响。在不同条件（温度、酸、有机溶剂、碱）下进行提取。F的甲醇/水提取物（25℃和80℃）显示存在异槲皮苷/芦丁、槲皮素、山奈酚和两个未鉴定的峰（II和III）。在酸性条件下（80℃时更明显），一些成分的提取量增加：儿茶素、4-羟基苯甲酸、异槲皮苷/芦丁、II、III。当进行甲醇/丙酮/水提取时，观察到对香豆酸和一个新的未鉴定峰（IV）。约15%的总酚——即对香豆酸、芦丁/异槲皮苷和山奈酚——与蛋白质部分相连。分离出蛋白质（I）后，一些原本以可溶形式存在（如儿茶素）以及与蛋白质结合部分中的化合物含量降低。面粉的模拟胃肠道消化释放出一些与蛋白质结合的酚类物质（儿茶素、酚酸），它们显著提高了大多数提取物的氧自由基吸收能力（ORAC）和2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）活性。消化后异槲皮苷/芦丁、槲皮素和山奈酚仍然存在。消化后的分离蛋白提取物在组成上存在差异，其中一些提取物的ORAC和/或ABTS活性较低。对模拟胃肠道消化过程对生物可及性和抗氧化活性的影响的研究（据我们所知，此前尚未对苋菜多酚进行过这方面的研究）取得了有前景的结果，这表明苋菜粉是一种潜在的抗氧化功能成分。
