Tocklai Yellow Tea - a diversified product from available cultivars: process standardization and chemical profiling

Abstract

Yellow tea, also known as huangcha in Chinese, is a lightly fermented unique specialty tea. In recent times it is gaining popularity because of its pleasant flavour (smell), mellow taste and for reported health benefits. The processing technique involves withering, partial fixing (enzyme deactivation), cooling and rolling followed by sealed yellowing or piling at different levels of moisture content in leaf and drying. Experiments were carried out to standardize the processing techniques of yellow tea with existing popular cultivars. Withering was carried out to 72 – 74% water content and piling or yellowing was extended up to 72 hrs. Overall quality of the experimental samples with 48 hrs piling time was found to be better as per the panel of tasters. The key chemical components responsible for yellow colour of liquor, their relationship with piling time and temperature along with the degree of yellowing during the process were studied. Substantial decrease in polyphenols and slight increase in caffeine content were observed during the yellowing.

Keywords: yellow tea; yellowing piling; catechins, partially oxidized.