알칼리 이온수로 제조한 녹차의 품질 특성 = Quality Properties of Green Tea Prepared with Alkaline Ionized Water

다국어 초록 (Multilingual Abstract)

The physicochemical characteristics of green tea prepared by four kinds of alkaline ionized water (AIW; pH 8.57, 8.85, 9.23, and 10.06, respectively) were evaluated. Green tea was made by soaking commercial green tea leaves in AIW at $75^{\circ}C$ for 10 min (1.0 g/100 mL). Total phenol contents, total flavonol contents, and ascorbic acid contents of green tea decreased with increasing pH of AIW. Increasing pH of AIW tended to decrease lightness (L) and redness (a) of green tea but increase yellowness (b) in Hunter color values. The amount of epicatechins and radical scavenging activity of green tea also decreased with increasing pH of AIW, while caffeine was not significantly affected. Tyrosinase inhibition activity was the highest in AIW of pH 8.85.

국문 초록 (Abstract)

시판되고 있는 녹차잎을 $75^{\circ}C$에서 알칼리 이온수로 10분간 추출하여 녹차를 제조한 뒤, 물리화학적 특성을 분석하였다. 알칼리 이온수로 제조한 녹차의 총 페놀 함량, 총 플라바놀 함량과 아스코르브산 함량은 pH가 증가할수록 감소하는 경향을 보였다. Hunter 색도 L, a, b값은 pH 증가에 따라 각각 감소, 감소, 증가하는 경향을 나타내었다. 녹차의 주된 성분인 epicatechin류의 함량은 pH가 증가할수록 감소하였고, 카페인은 유의차를 나타내지 않았다. DPPH 라디칼 소거능도 pH가 증가할수록 감소하였으며, tyrosinase 억제능은 pH 8.85의 알칼리 이온수 녹차에서 가장 높게 측정되었다.

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