Effects of vacuum freeze-drying on the quality of DanCong OoLong tea

Traditional Dancong tea dried in oven; however, the technique of drying in vacuum freezing method is obviously more energy efficiency than it. The effects of using this new method in drying process of tea manufacturing through the test of sensory characteristics of tea and the determination of biochemistry components are showed in this paper. The outstanding mellow taste of the product after drying with vacuum freezing technique is the main effect of the new method. The experiments show that the best approach is using this new method after elementary drying in oven. The experiments depict that using the vacuum freezing technique without initial drying in oven is not advantaged for the quality of tea.