Effect of tea manufacturing processes and cultivars on tea infusion color

Tea, one of the most popular beverages worldwide, is produced from the tender leaves of Camellia sinensis through complex chemical processes. Tea quality is largely determined by its aroma and color, which are influenced by the tea's manufacturing process and cultivar. However, limited research has explored the combined effects of processing methods and tea cultivars on tea infusion color. This study compared the effects of semi-fermented oolong tea and fully fermented black tea processing on infusion color using Taiwan Tea Experiment Station (TTES) No. 18 and Chin-shin cultivars. The results revealed that oolong tea processing minimized polyphenol oxidase activity and preserved catechins, resulting in a lighter infusion color. In contrast, black tea processing enhanced theaflavin production, deepening the yellow-orange color of the tea infusion. TTES No. 18, with higher catechin content, exhibited a darker tea color compared to Chin-shin. This study highlights the significant influence of processing methods and tea cultivar on infusion color. Oolong tea processing maintains catechin levels and a lighter color, while black tea processing intensifies theaflavin content and deepens the color. These findings provide insights into optimizing tea production to enhance the visual quality of tea infusions.