Czernicka Maria, Zaguła Grzegorz, Bajcar Marcin, Saletnik Bogdan, Puchalski Czesław
University of Rzeszow, Faculty of Biology and Agriculture, Department of Bioenergetics and Food Analysis, Rzeszow, Poland
Rocz Panstw Zakl Hig. 2017;68(3):237-245.
The processing of tea leaves determines the contents of bioactive ingredients, hence it should be expected that each variety of tea, black, red or green, will represent a different package of compounds of physiological importance. Taste and aroma, as well as price and brand are the main factors impacting consumers’ preferences with regard to tea of their choice; on the other hand consumers less frequently pay attention to the chemical composition and nutritional value of tea.
The purpose of the study was assessment of the nutritional value of black, green and white high-quality tea leaf from Chinese plantations based on the chemical composition of the dried leaves as well as minerals and caffeine content in tea infusions.
The research material included 18 high-quality loose-leaf teas produced at Chinese plantations, imported to Poland, and purchased in an online store. The analyses included examination of the dried tea leaves for their chemical composition (contents of water, protein, volatile substances and ash) and assessment of selected minerals and caffeine contents in the tea infusions.
High-quality Chinese green teas were found with the most valuable composition of minerals, i.e. the highest contents of Zn, Mn, Mg, K, Ca and Al and the highest contents of protein in comparison to the other products. Chinese black teas had the highest contents of total ash and caffeine and white teas were characterized with high content of volatile substances, similar to the black teas, and the highest content of water and the lowest content of total ash.
The three types of tea brews examined in the present study, in particular green tea beverages, significantly enhance the organism’s mineral balance by providing valuable elements
茶叶的加工方式决定了生物活性成分的含量，因此可以预期，红茶、红茶或绿茶的每个品种都将代表不同的具有生理重要性的化合物组合。口味、香气以及价格和品牌是影响消费者对所选茶叶偏好的主要因素；另一方面，消费者较少关注茶叶的化学成分和营养价值。
本研究的目的是根据干茶叶的化学成分以及茶浸液中的矿物质和咖啡因含量，评估来自中国种植园的优质红茶、绿茶和白茶的营养价值。
研究材料包括18种在中国种植园生产、进口到波兰并在网上商店购买的优质散叶茶。分析包括检测干茶叶的化学成分（水、蛋白质、挥发性物质和灰分的含量）以及评估茶浸液中选定的矿物质和咖啡因含量。
发现优质中国绿茶具有最有价值的矿物质组成，即与其他产品相比，锌、锰、镁、钾、钙和铝的含量最高，蛋白质含量也最高。中国红茶的总灰分和咖啡因含量最高，白茶的特点是挥发性物质含量高，与红茶相似，水分含量最高，总灰分含量最低。
本研究中检测的三种茶冲泡液，特别是绿茶饮料，通过提供有价值的元素，显著增强了机体的矿物质平衡
