Šťastná Kristýna, Mrázková Martina, Sumczynski Daniela, Cındık Betül, Yalçın Erkan
Department of Food Analysis and Chemistry, Tomas Bata University in Zlín, Vavrečkova 275, 760 01 Zlín, Czech Republic.
Department of Food Engineering, Bolu Abant Ízzet Baysal University, Gölköy Campus, 14030 Bolu, Turkey.
Antioxidants (Basel). 2019 Nov 16;8(11):565. doi: 10.3390/antiox8110565.
Nowadays, there is a growing interest for foods with a lower sugar content and rich in fiber and biologically active substances. The main purpose of this study was to prepare flakes from non-traditional pigmented cereals (, and ) and to analyze their fibre, sugar, and in vitro digestibility values. Regarding phenolic antioxidants (soluble, soluble conjugated, and insoluble bound fractions), their content and antioxidant activity were measured using spectrophotometry and high performance liquid chromatography (HPLC) methods. Hydrothermally treated grains resulted in flakes with higher total dietary fibre contents (11.1-24.4%), quinoa and teff flakes were rich in maltose (up to 42.0 mg/g). Non-traditional flakes had lower in vitro digestibility, but conversely, they exhibited the highest phenolic contents corresponding with the highest antioxidant activity values (up to 2.33 mg Gallic acid equivalent/g of total phenolic content and 1.59 mg Trolox equivalent/g for 2,2-diphenyl-1-picrylhydrazyl (DPPH) in case of brown teff). Among free phenolics, the main contributors to an antioxidant activity were -coumaric, -coumaric, and gallic acids ( > 0.8186); among the soluble conjugated fractions, they were epigallocatechin, epicatechin, caffeic, and vanillic acids ( > 0.5935); while caffeic, protocatechuic, and ferulic acids ( > 0.5751) were the main contributors among the insoluble bound phenolics.
如今，人们对低糖、富含纤维和生物活性物质的食品越来越感兴趣。本研究的主要目的是用非传统的有色谷物（、和）制备片状食品，并分析其纤维、糖和体外消化率值。关于酚类抗氧化剂（可溶性、可溶性共轭和不溶性结合部分），使用分光光度法和高效液相色谱（HPLC）方法测量其含量和抗氧化活性。经水热处理的谷物制成的片状食品膳食纤维总含量较高（11.1 - 24.4%），藜麦和画眉草片状食品富含麦芽糖（高达42.0毫克/克）。非传统片状食品的体外消化率较低，但相反，它们表现出最高的酚类含量，相应地抗氧化活性值也最高（对于棕色画眉草片状食品，总酚含量高达2.33毫克没食子酸当量/克，2,2 - 二苯基 - 1 - 苦基肼（DPPH）抗氧化活性高达1.59毫克 Trolox 当量/克）。在游离酚类中，对抗氧化活性起主要作用的是 - 香豆酸、 - 香豆酸和没食子酸（> 0.8186）；在可溶性共轭部分中，是表没食子儿茶素、表儿茶素、咖啡酸和香草酸（> 0.5935）；而在不溶性结合酚类中，主要贡献者是咖啡酸、原儿茶酸和阿魏酸（> 0.5751）。
