Study of sterilization methods for sun-dried green tea.

In order to screen out the appropriate sterilization method for sun-dried green tea, six sterilization methods including irradiation sterilization, ultraviolet sterilization, microwave sterilization, high-pressure steam sterilization, pasteurization and ozone sterilization were used to treat sun-dried green tea, then total viable counts, biochemical composition and sensory evaluation of sun-dried green tea after sterilization were determined. The results showed that microorganisms in tea leaves were sterilized fully by methods of high-pressure steam sterilization and irradiation sterilization, 7.5 kGy irradiation sterilization had the least effect on the biochemical compositions of tea, only the contents of soluble sugar, catechin, flagellin, rutin and luteolin changing significantly (P<0.05). Meanwhile, sensory evaluation also confirmed that 7.5 kGy irradiation sterilization had the least effect on sensory quality of sun-dried green tea. In conclusion, the best sterilization method of sun-dried green tea was 7.5 kGy irradiation sterilization. [ABSTRACT FROM AUTHOR]