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        검색결과 4

        1.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the chemical composition of green tea, white tea, yellow tea, oolong tea and black tea with respect to extraction temperature and time. The optimum extraction conditions for these teas were determined by assessing the chemical composition of tea brewed at different temperature (50, 60, 70, 80℃) and extraction times (1, 3, 5, 10 minute). Catechins contents were the largest at 5 minutes and generally declined by 10 minutes. Green tea catechins contents were highest when brewed at 70℃ and besides other teas a change of the trend variation at 70 and 80℃. These temperatures did not extract theaflavins in green tea. Extract temperature and time did not significantly affect theaflavins content of white tea, yellow tea, and oolong tea. Black tea, however, was noticeably dependent on extract conditions, which were most effective at 70℃, brewed for 5 minutes. Caffeine content of green tea, yellow tea, and oolong tea was highest at 5 minutes, but temperature did not appear to affect the content. White tea and black tea caffeine content was highest when brewed at 70℃ for 5 minutes. Theobromine content of green tea, yellow tea, oolong tea, and black tea did not show major differences between the study times or temperature, though the content in white tea increased with higher temperatures when brewed for 5 minutes. The extraction of phenolic compounds increased until 5 minutes, and showed not further increase at 10 minutes. Antioxidant capacity of green tea, white tea, and yellow tea were maximized at 70℃ for 5 minutes or 80℃ for 3 minutes, while oolong and black tea were reached maximum antioxidants at 70℃ for 5 minutes. In general, to optimize the beneficial chemical content of brewed tea, a water temperature of 70℃ for 5 minutes is recommended.
        4,000원
        2.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Yellow tea thrip (Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is anthophilous pests of many crops worldwide including five flavor berry. And the mealy bug (Pseudaulacaspis cockerelli (Cooley) (Hemiptera: Diaspididae)) is one of the hardest pests to control. Its body is covered with white waxy threads, which often make a chemical pest control useless. Five flavor berry (Schisandra chinensis Baill) is used in traditional Chinese medicine. So, the development of biological control against the major pest on five flavor berry is of great interest. In this work, a treatment of Chrysoperla nipponensis (Okamoto) was applied to five flavor berry fields infested by P. cockerelli and a treatment of Amblyseius swirskii Athias-Henriot was applied to two types of five flavor berry fields infested by S. dorsalis. Even though our tests found significant differences between the two culturing method(sod culture, nonwoven type mulching), the treatment of biological control agents decreased or a little increased the fruit damage, which was comparable to the chemical insecticide treatment. In the sod culture experiment, thrip population was significantly low and increased at a lower rate than in the nonwoven type mulching. It may be suggested from these results that A. swirskii and C. nipponensis as IPM program and sod culture could be incorporated into the integrated pest management system on five flavor berry.
        4,000원