Abstract: This study explored the effects of different processing methods (pan fixation and oven drying, microwave fixation and oven drying, and vacuum freeze drying) on the contents of water extracts, tea polyphenols, free amino acids, catechins and alkaloids and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity in tea manufactured from the fresh flowers of Camellia sinensis cv. Huangjingui. Results indicated that the contents of tea polyphenols, free amino acids, epigallocatechin, epicatechin, epigallocatechin gallate, epicatechin gallate and methyl epicatechin gallate in freeze-dried samples were significantly higher than those in samples prepared by two other methods (P < 0.05), and the content of gallic acid was the lowest among these three samples. However, no significant difference in the contents of water extracts, theogallin, and caffeine was seen among all samples (P > 0.05). Vacuum freeze drying was most beneficial for maintaining tea polyphenols, imparting the strongest DPPH radical scavenging capacity to the tea, followed in decreasing order by microwave fixation and oven drying, and pan firing and oven drying. Sensory evaluation revealed that tea samples prepared by pan fixation and oven drying, and microwave fixation and oven drying had typical corn-like flavor due to thermal dehydration. Both products tasted numbing and astringent, and the freeze-dried product had the strongest astringent taste. The different processing methods produced different sensory flavors. To sum up, tea plant flowers can be developed into a functional drinks.

Key words: drying technology, catechins, theogallin, antioxidant capacity