Cocoa tea (Camellia ptilophylla Chang), a natural decaffeinated species of tea – Recommendations on the proper way of preparation for consumption

Special tea products featuring functional components: Health benefits and processing strategies

The functional components in tea confer various potential health benefits to humans. To date, several special tea products featuring functional components (STPFCs) have been successfully developed, such as O-methylated catechin-rich tea, γ-aminobutyric acid-rich tea, low-caffeine tea, and selenium-rich tea products. STPFCs have some unique and enhanced health benefits when compared with conventional tea products, which can meet the specific needs and preferences of different groups and have huge market potential. The processing strategies to improve the health benefits of tea products by regulating the functional component content have been an active area of research in food science. The fresh leaves of some specific tea varieties rich in functional components are used as raw materials, and special processing technologies are employed to prepare STPFCs. Huge progress has been achieved in the research and development of these STPFCs. However, the current status of these STPFCs has not yet been systematically reviewed. Here, studies on STPFCs have been comprehensively reviewed with a focus on their potential health benefits and processing strategies. Additionally, other chemical components with the potential to be developed into special teas and the application of tea functional components in the food industry have been discussed. Finally, suggestions on the promises and challenges for the future study of these STPFCs have been provided. This paper might shed light on the current status of the research and development of these STPFCs. Future studies on STPFCs should focus on screening specific tea varieties, identifying new functional components, evaluating health-promoting effects, improving flavor quality, and elucidating the interactions between functional components.

Variation of Major Chemical Composition in Seed-Propagated Population of Wild Cocoa Tea Plant Camellia ptilophylla Chang

Excessive intake of high-caffeine tea will induce health-related risk. Therefore, breeding and cultivating tea cultivars with less caffeine is a feasible way to control daily caffeine intake. Cocoa tea (Camellia ptilophylla Chang) is a wild tea plant which grows leaves with little or no caffeine. However, the vegetative propagation of cocoa tea plants is difficult due to challenges with rooting. Whether natural seeds collected from wild cocoa tea plants can be used to produce less-caffeinated tea remains unknown, because research on the separation of traits among the seed progeny population is lacking. The present study was set to investigate the variation of caffeine and other chemical compositions in seed-propagated plant individuals using colorimetric and HPLC methods. It shows that there were great differences in chemical composition among the seed-propagated population of wild cocoa tea plants, among which some individuals possessed caffeine contents as high as those of normal cultivated tea cultivars (C. sinensis), suggesting that the naturally seed-propagated cocoa tea seedlings are not suitable for directly cultivating leaf materials to produce low-caffeine tea. Therefore, the cocoa tea plants used for harvesting seeds for growing low-caffeine tea plants should be isolated in order to prevent their hybridization with normal cultivated C. sinensis plants. Interestingly, the leaves of cocoa tea seedlings contained high levels of gallocatechin gallate (GCG) and would be a good source of leaf materials for extracting more stable antioxidant, because GCG is a more stable antioxidant than epigallocatechin gallate (EGCG), the dominant component of catechins in normal cultivated tea cultivars. Some plant individuals which contained low levels of caffeine along with high levels of amino acids and medium levels of catechins, are considered to be promising for further screening of less-caffeinated green tea cultivars.

Inhibitory effect of black tea (Camellia sinensis) theaflavins and thearubigins against HCT 116 colon cancer cells and HT 460 lung cancer cells

Recently, phytochemical-based dietary intervention has gained attention as a preventive and curative strategy against cancers owing to their safety, better tolerance, and economics. Against this background, black tea extract which contains the flavanol-3-ol, theaflavins (TF), and thearubigins (TR) with promising anti-oncogenic activity were assessed to determine its in vitro inhibitory impact on colon cancer (HCT 116) and lung cancer cell lines (HT 460). In a dose-dependent manner, results revealed that TF, TR, and their combinations cause inhibition in cell viability. However, TF imparted a maximum reduction in cell viability of HCT 116 and HT 460. Flow cytometry data revealed that TF, TR, and their combinations exhibited substantial cell arrest at the G2/M phase. The influence was more prominent in lung cancer cells (HT 460) when compared with colon cells (HCT 116). All treatments resulted in apoptosis, however, the combination of TF and TR exhibited the highest apoptotic ability in comparison to individual treatments. TF and TR exhibited a synergistic impact and significantly inhibited cell proliferation of HCT 116 and HT 460 in dose- and time-dependent manners by inducing apoptosis and cell cycle arrest, wherein TF showed a more pronounced impact. PRACTICAL APPLICATIONS: Results from the present study revealed that black tea-isolated polyphenols (TF and TR) exhibited a significant inhibition of lung and colon cancer cell growth. A promising synergistic effect of TF and TR as inhibitors of cancer cells was observed. More clinical work, perhaps on a human subject, is needed before these two isolated compounds can be prescribed as anticancer drugs.