Effect of selenium spraying on green tea quality

This research was conducted to determine the effects of different selenium treatments on the sensory and chemical qualities of green tea harvested in the summer tea-producing season. Green tea was produced from fresh tea leav es sprayed with sodium selenite or organically bound selenium solution. The results showed that the sweetness and aroma of green tea extracts were sig nificantly increased and the astringent taste and bitterness were significa ntly reduced by selenium spraying during the summer tea-producing season. S ignificant differences in astringent taste, bitterness and sweetness of gre en tea extracts were found between sodium selenite and organically bound se lenium treatments. The total amino acid and vitamin C contents of green tea were significantly increased and the ratio of polyphenols and amino acids was significantly decreased by selenium spraying. The vitamin C content of green tea during storage was more stable as a result of selenium treatment. No significant difference was found between sodium selenite and organicall y bound selenium treatments. These results demonstrate that the sensory and chemical qualities of green tea were significantly improved by selenium sp raying. (C) 2001 Society of Chemical Industry.