Advances in research on correlation between drying method and aroma quality of fragrant oolong tea

Abstract: Oolong tea is one of the six major teas in China. It has a rich and sweet taste and a rich aroma. It combines the quality of natural flowers and fruit and the variety of flavors. According to the degree of fermentation, it can be divided into fragrant oolong tea and fragrant oolong tea.

Different processing techniques determine the quality of the fragrant oolong tea, and the microwave drying equipment is an important process that affects the aroma quality of the fragrant oolong tea. The full text mainly summarizes the influence of different drying methods on the aroma quality of the fragrant oolong tea, and provides a reference for the production of high-quality fragrant oolong tea.

Key words: drying method; oolong tea microwave drying; aroma quality

Oolong tea originated in Fujian and is the second largest tea in China after production and export. It is different from other teas in its natural and varied floral and fruity flavors and special flavors. The quality characteristics of Oolong tea are affected by tea variety, ecological environment, cultivation management, harvesting season, raw material tenderness and tea making process. According to the production area, it can be divided into four categories: Weibei Oolong Tea, Weinan Oolong Tea, Guangdong Oolong Tea and Taiwan Oolong Tea.

In recent years, in the traditional Minnan oolong tea process, Taiwan's oolong tea "light fermentation" and contemporary "air conditioning green" and other innovative technologies have been introduced to produce a fragrant oolong tea with "three green" quality. Its shape is hemispherical and the body is heavy. The color is dark green or green and lustrous; the fragrance is long-lasting, the soup is yellow-green, and the taste is sweet; the leaf bottom is thick and the yellow-green is even.

In particular, the high-grade fragrant oolong tea is influenced by its "green" (dry tea and soup green or yellow-green), "fragrant" (with natural flowers and fruit), and "flavored" (tasteful and mellow). It is favored by consumers in the flower tea sales area. Although the market of fragrant oolong tea has broad prospects, its color, aroma, taste and shape are inevitably brought into new influences and repositionings of its unique flavor (such as "phony" deficiency) compared with traditional oolong tea.

In addition to the techniques of “low temperature, light shaking, thin spreading, long drying” and “cold drying”, the fragrant oolong tea also needs “low temperature slow drying” to maintain the freshness and pure aroma of its dry tea. “Three Greens” features unique flavors such as mellow and fresh.

In the process of processing, how to make the fragrant black tea "color", "fragrance" and "flavor" are good. In addition to the key processes such as "light fermentation" and "air conditioning and greening", the drying technology affects the fragrance of fragrant oolong tea. The important process of quality is now analyzed to provide a reference for the production of high-quality fragrant oolong tea.