Tea Research Institute, China Academy of Agricultural Sciences, Hangzhou, China.
Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark.
J Sci Food Agric. 2022 Aug 15;102(10):4131-4139. doi: 10.1002/jsfa.11762. Epub 2022 Feb 7.
People brew tea to drink an infusion that only contains 25% water-soluble constituents, leading to most of the insoluble materials being wasted. Tea powder could be drunk directly by mixing with water without producing any waste. Tea powder can also be used as a natural additive to improve the flavour and taste in beverages and foods. Much detailed information on the particle properties of tea powder is required with its increasing consumption. The aim of this study was to investigate the effects of particle size ranging from median diameter D = 4.32 to 26.59 μm on the composition, physical, rheological, and bioactive properties of black tea powder.
The results indicate that large powder sizes had high bulk density and flowability, whereas small powder sizes possessed good swelling ability and wettability. The contents of water extract, total polyphenols, crude fibre, catechins, and thearubigins reduced with a decrease in particle size. To change the particle size and concentration could adjust the elastic modulus and the viscous modulus of the black tea powder suspension. Moreover, black tea powder with small particle size could regulate blood lipids in a hyperlipidaemic rat model by lowering triacylglycerols and elevating high-density lipoprotein cholesterol, whereas large particles presented an advantage in reducing body weight.
Our investigation extended the knowledge of commercial black tea powder in composition, physical, rheological, and bioactive properties. These results lay the foundation for future exploration of the use of tea powder in the food industry. © 2022 Society of Chemical Industry.
人们泡茶喝的是一种只含有 25%水溶性成分的浸提液，导致大部分不溶性物质被浪费掉。茶粉可以直接与水混合饮用，不会产生任何浪费。茶粉也可以用作天然添加剂，改善饮料和食品的风味和口感。随着茶粉消费的增加，需要更多关于茶粉颗粒特性的详细信息。本研究的目的是研究粒径范围从中值直径 D = 4.32 到 26.59 μm 对红茶粉组成、物理、流变和生物活性特性的影响。
结果表明，大颗粒尺寸具有高堆密度和流动性，而小颗粒尺寸具有良好的溶胀能力和润湿性。随着粒径的减小，水提取物、总多酚、粗纤维素、儿茶素和茶黄素的含量降低。改变粒径和浓度可以调节红茶粉悬浮液的弹性模量和粘性模量。此外，小颗粒尺寸的红茶粉通过降低三酰甘油和升高高密度脂蛋白胆固醇来调节高脂血症大鼠模型中的血脂，而大颗粒则有利于降低体重。
我们的研究扩展了商业红茶粉在组成、物理、流变和生物活性特性方面的知识。这些结果为未来探索茶粉在食品工业中的应用奠定了基础。© 2022 英国化学学会。
