Department of Food Engineering, Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, 34303 Halkali, Istanbul, Turkey.
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
Food Res Int. 2021 Feb;140:110039. doi: 10.1016/j.foodres.2020.110039. Epub 2021 Jan 8.
In this study, four Brassicaceae microgreens species, namely kale, red cabbage, kohlrabi, and radish, were evaluated for their phytochemical compositions using spectrophotometric assays and untargeted metabolomics before and after in vitro gastrointestinal digestion. According to the in vitro spectrophotometric results, significant amounts of phenolics could be detected in each studied species, thus supporting the total antioxidant capacities recorded. Overall, metabolomics allowed annotating a total of 470 phytochemicals across the four Brassicaceae microgreens, either fresh or digested. Among polyphenols, flavonoids were the most represented class (180 compounds, including anthocyanins, flavones, flavonols, and other flavonoids), followed by phenolic acids (68 compounds, mainly hydroxycinnamic and hydroxybenzoic acids), non-flavonoid or phenolic acid-based structures (i.e., alkyl- and alkylmethoxy-phenols and tyrosol derivatives), and lignans. Also, 22 glucosinolates were annotated, including gluconapin glucoraphanin, glucobrassicin, and 4-hydroxyglucobrassicin. Noteworthy, significant differences could be observed in terms of bioaccessibility as a function of the phenolic class and the species considered. Overall, lignans exhibited the highest bioaccessibility values (14%), followed by tyrosol derivatives and flavonoids (on average, 9% and 8%, respectively). However, differences could be evidenced as a function of the species, with red cabbage having comparatively lower bioaccessibility values irrespective of the chemical class of bioactive considered. Similarly, bioaccessibility of glucosinolates significantly differed across species, ranging from 2% in kale to 43% in kohlrabi microgreens.
在这项研究中，评估了四种芸薹属微绿蔬菜（羽衣甘蓝、红甘蓝、球茎甘蓝和萝卜）的植物化学组成，使用分光光度法测定和非靶向代谢组学方法，分别在体外胃肠道消化前后进行分析。根据体外分光光度结果，每个研究品种都可以检测到大量的酚类物质，从而支持记录的总抗氧化能力。总的来说，代谢组学可以在四种芸薹属微绿蔬菜中总共注释 470 种植物化学物质，无论是新鲜的还是消化过的。在多酚中，黄酮类化合物是最主要的类别（180 种化合物，包括花青素、黄酮、黄酮醇和其他类黄酮），其次是酚酸（68 种化合物，主要是羟基肉桂酸和羟基苯甲酸）、非黄酮类或酚酸类结构（即烷基和烷氧基-酚类和酪醇衍生物）和木脂素。此外，还注释了 22 种硫代葡萄糖苷，包括葡萄糖苷、葡萄糖苷、葡萄糖苷和 4-羟基葡萄糖苷。值得注意的是，根据酚类类别和所考虑的物种，生物可利用性方面可以观察到显著差异。总的来说，木脂素表现出最高的生物可利用性值（14%），其次是酪醇衍生物和类黄酮（平均分别为 9%和 8%）。然而，根据物种的不同，可以发现差异，红甘蓝无论考虑的生物活性化学类别如何，其生物可利用性值都相对较低。同样，硫代葡萄糖苷的生物利用度在不同物种之间也有显著差异，从羽衣甘蓝的 2%到球茎甘蓝的 43%不等。
