논문 상세보기
pp.333-341
3개월간 다른 조건에서 저장한 잎 및 분말녹차의 항산화 활성 변화를 조사하였다. 녹차 추출물은 수분활성도(0.81, 0.69, 0.23)와 온도(, , )를 달리하여 3개월간 저장한 잎 및 분말녹차 시료 1.5 g에 의 탈이온수 100mL를 첨가하여 5분간 추출하여 준비하였다. 항산화 특성은 환원력, DPPH radical 소거활성, FRAP 측정법을 이용하여 조사하였다. 모든 실험에서 분말녹차 추출물이 잎녹차 추출물보다 높은 활성을 나타내었으며
The antioxidant properties of green tea leaves and powder extracts were determined using several tests including estimation of reducing power, DPPH(1,1-diphenyl-2- picrylhydrazyl) radical-scavenging activity, and FRAP(Ferric reducing/antioxidant power) assay. All tests indicated that extracts of green tea powder had higher antioxidant activities than extracts of green tea leaves, and the activities were concentration-dependent. However, each test yielded somewhat different results with respect to storage conditions. The reducing power of green tea leaves was highest at , storage at , and an Aw(water activity) value of 0.23. However, the reducing power of green tea powder, assayed at , was high under all storage conditions(with variations in temperature and Aw), and was about 1.5.2-fold greater than that of green tea leaves. Radical-scavenging activity, as assessed by the DPPH assay, increased in a dose-dependent manner over the range . At higher concentrations, activities were of maximal were attained. The FRAP activity of green tea extract also increased with rising concentration. Particularly in the case of green tea leaves, antioxidant activity was most greatest with storage at and Aw values of 0.69 and 0.23 when assayed at a concentration of . These results indicate that the most important factor during storage of green tea is not the Aw value but rather temperature, and that use of refrigeration() is preferable to increase or maintain the antioxidant activities of biological components in green tea.
