Department of Food Analysis and Chemistry, Tomas Bata University in Zlín, Zlín, Czech Republic.
Language Centre, Tomas Bata University in Zlín, Zlín, Czech Republic.
J Sci Food Agric. 2018 Jun;98(8):3014-3021. doi: 10.1002/jsfa.8800. Epub 2018 Jan 3.
Total phenolic content, phenolic profile and antioxidant activity were determined in free and bound phenolic fractions of thermally treated brown and white teff grains.
Phenolic content in raw brown and white teff (1540 and 992 mg gallic acid equivalent kg ) as well as antioxidant activity (6.3 and 5.5 mmol trolox equivalent kg ) were higher in free phenolic fractions. The most significant decrease in total phenolics was observed after application of the sous-vide method (35% for brown teff and 11% for white teff). Main free phenolics of heat-treated teff were ferulic, protocatechuic, p-coumaric and ellagic acids, rutin and epigallocatechin. Main bound phenolics were ferulic, gallic, sinapic and ellagic acids, catechin and epigallocatechin. The detrimental effect on free and bound quercetin and bound cinnamic acid concentrations was also examined during heat treatment. Thermally treated brown teff showed a high level of in vitro organic matter digestibility if water cooking and rice cooker (both 99.5%) and sous-vide (96.5%) methods were applied.
The sous-vide method may be recommended as the most suitable hydrothermal treatment for grains of teff when compared with water cooking and rice cooker methods. © 2017 Society of Chemical Industry.
本研究测定了热处理后的棕色和白色埃塞俄比亚画眉草谷粒中游离态和结合态酚类物质的总酚含量、酚类组成和抗氧化活性。
生的棕色和白色埃塞俄比亚画眉草中的游离态酚类物质含量（分别为 1540 和 992mg 没食子酸当量/kg）和抗氧化活性（分别为 6.3 和 5.5mmol trolox 当量/kg）均较高。在应用低温慢煮法后，总酚含量的降幅最大（棕色埃塞俄比亚画眉草降低 35%，白色埃塞俄比亚画眉草降低 11%）。热处理后埃塞俄比亚画眉草中的主要游离态酚类物质为阿魏酸、原儿茶酸、对香豆酸和鞣花酸、芦丁和表没食子儿茶素。主要的结合态酚类物质为阿魏酸、没食子酸、丁香酸和鞣花酸、儿茶素和表没食子儿茶素。在热处理过程中，还检测到游离态和结合态槲皮素及结合态肉桂酸浓度的有害变化。应用水煮法和电饭煲煮饭法（均为 99.5%）及低温慢煮法（96.5%）处理后，热处理的棕色埃塞俄比亚画眉草表现出较高的体外有机物消化率。
与水煮法和电饭煲煮饭法相比，低温慢煮法可能是埃塞俄比亚画眉草谷物最适宜的湿热处理方法。 © 2017 英国化学学会。
