Paiva Lisete Sousa, Dias Ana Paula, Motta Madalena Hintze, Baptista José António Bettencourt
Department of Science of Physics, Chemistry and Engineering of Faculty of Science and Technology and Institute of Agricultural and Environmental Research and Technology (IITAA), University of Azores, 9500-321 Ponta Delgada, Portugal.
Gorreana Tea Plantation, Gorreana, 9625-304 Maia, Portugal.
Plants (Basel). 2025 Jan 2;14(1):103. doi: 10.3390/plants14010103.
tea has received considerable attention due to its beneficial effects on health, particularly due to its antioxidant properties that are affected by several factors, which have a high influence on the final quality of black tea. The objective of this study was to investigate the biological properties of Azorean black tea from five different zones of tea plantation in order to select specific areas to cultivate tea rich in targeted compounds beneficial to human health. The free radical scavenging activity (FRSA), ferric reducing antioxidant power (FRAP), ferrous ion chelating (FIC) activities, total phenolic content (TPC), total flavonoid content (TFC), and tannins were determined by colorimetric methods, and catechin and theaflavin contents were analyzed by high-pressure liquid chromatography. The results indicated that samples from Zone E (341 m above the sea level) presented higher values of FRSA (EC = 7.22 µg/mL), FRAP (EC = 9.06 µg/mL), and FIC activities (79.83%) and higher values of total phenolics (264.76 mg GAE/g DE) and almost all catechins. For TFC, the values were very similar between zones, and for theaflavins content, Zone A showed the best levels, followed by Zone E. In general, these results clearly highlight that altitude plays a significant role in enhancing certain compounds of tea, thereby influencing its quality.
茶因其对健康的有益影响而受到广泛关注，特别是其抗氧化特性，而这些特性会受到多种因素的影响，这些因素对红茶的最终品质有很大影响。本研究的目的是调查来自五个不同茶园区域的亚速尔红茶的生物学特性，以便选择特定区域来种植富含对人体健康有益的目标化合物的茶叶。通过比色法测定自由基清除活性（FRSA）、铁还原抗氧化能力（FRAP）、亚铁离子螯合（FIC）活性、总酚含量（TPC）、总黄酮含量（TFC）和单宁含量，并通过高压液相色谱法分析儿茶素和茶黄素含量。结果表明，来自E区（海拔341米）的样品具有较高的FRSA值（EC = 7.22 µg/mL）、FRAP值（EC = 9.06 µg/mL）和FIC活性（79.83%），以及较高的总酚含量（264.76 mg GAE/g DE）和几乎所有儿茶素的含量。对于TFC，各区域之间的值非常相似，对于茶黄素含量，A区表现出最佳水平，其次是E区。总体而言，这些结果清楚地表明，海拔高度在提高茶叶的某些化合物含量方面起着重要作用，从而影响其品质。
