Effect of a combined microwave assisted drying and air drying on improving active nutraceutical compounds, flavor quality, and antioxidant properties of Camellia Sinensis L. (cv. Longjing 43) flowers

Drying tea flowers into a high-quality product is important to its commodity value. In the present work, a combination of microwave-assisted drying and air drying (MAD-AD) was applied in the processing of fresh tea flowers and its effects on flavor quality, active nutraceutical compounds, and antioxidant capacities were studied. The results showed that compared to air drying and freeze drying tea flowers, the MAD-AD tea flowers had higher amounts of active compounds such as catechins, flavonol glycosides, and triterpenoid saponins, and possessed high antioxidant activities. Moreover, this drying method improved the tea flowers' color and preserved a more floral fragrance. This combined method could be of interest as an industrial method for drying tea flowers with the benefit of reduced processing time, more reserved active compounds and high quality of products.