RISS 검색 - 국내학술지논문

무료
기관 내 무료
유료

내보내기
내책장담기
한글로보기

정확도순

내림차순

내림차순

10개씩 출력

1
A comparative study of ultra-sonication and agitation extraction techniques on bioactive metabolites of green tea extract

Das, Protiva Rani,Eun, Jong-Bang Elsevier 2018 Food chemistry Vol.253 No.-
- 원문보기
Abstract The aim of this study was to compare methods for efficient extraction of green tea metabolites. Aqueous green tea leaf powder extracts were prepared by ultra-sonication extraction (UE), agitation extraction (AE), and the conventional extraction method (control) at different temperatures (60, 70, and 80 °C) and times (5–30 min). Compared to the control, both UE and AE techniques significantly increased the yields of polyphenols (three-fold), catechins (two-fold), and flavonoids (two-fold), and resulted in higher antioxidant activity. For both techniques, highest extraction efficiency of bioactive metabolites occurred at 80 °C for 20 min. Caffeine, total free amino acid, vitamin C, and total soluble solid contents were also significantly increased using either technique compared to the control. Thus, AE and UE have similar extraction efficiencies and could be used to prepare antioxidant-rich green tea extract or green tea extract powder. Highlights <UL> <LI> Agitation and sonication techniques increased the yields of green tea metabolites. </LI> <LI> Agitation and sonication showed similar extraction efficiencies of metabolites. </LI> <LI> Antioxidant activities of green tea extracts were increased by both techniques. </LI> <LI> Both techniques can be used to produce antioxidant-rich green tea extract. </LI> </UL>
2
차의 폴리페놀성분과 그 기능성

문선희(Sun Hee Moon),Protiva Rani Das,은종방(Jong Bang Eun) 한국차학회 2016 한국차학회지 Vol.22 No.3
- 원문보기
Tea is one of the most widely consumed beverages in the world due to its attractive color, flavor and health benefits. It has been used as a source of phenolic compounds. The phenolic compounds in tea are hydroxybenzoic acids such as gallic acid, vanillic acid, galloylquinic acid protocatechuic acid, coumaryl quinic acid and galloylated derivatives. Hydroxybenzoic acids have the potential to treat different health complications. Phenolic acid is considered to be a strong antioxidant likely antidiabetic, anticancer, antimicrobial, and neuroprotective activity. The connection between tea consumption and its health benefits is related to its phenolic compound contents. Tea is extremely rich in gallic acid derivatives which exhibit free radical scavenger activity, as well as inducing apoptosis. Therefore, in this study, the phenolic compounds in tea and their physiological effects, which have been reported in various studies, are discussed. Simultaneously, the primary identified phenolic compounds of tea are summarized and their related properties are examined in detail.