반응표면분석법을 이용하여 양파의 추출조건에 따른 기능성을 모니터링하였다. 중심합성계획법에 따라 마이크로웨이브 에너지 (30$sim$150 watt), 에탄올 농도(0$sim$100%), 추출시간(1$sim$9분)을 달리하였을 때 회귀식 $R^2$는 추출수율, 전자공여작용, tyrosinase 저해효과 및 SOD 유사활성에서 각각 0.8835, 0.8759, 0.8067과 0.8926으로 분석되었다. 조건별 추출물의 수율, 전자공여능, tyrosinase 저해효과, SOD 유사활성에 대한 4차원 반응표면을 superimposing하여 얻은 최적추출조건 범위는 마이크로웨이브 에너지 0$sim$120 watt, 에탄올 농도 70$sim$90%, 추출시간 2$sim$10분으로 나타났다. 최적추출조건 범위내의 임의의 조건인 마이크로웨이브 에너지 60 watt, 에탄올 농도 80%, 추출시간 6분을 각각의 회귀식에 대입하여 얻은 예측값은 추출물의 수율 17.88%,전자공여능 17.81%, tyrosinase 저해효과 42.51%, SOD 유사활성 27.35%로 나타났다.
Extraction characteristics of onion (Allium cepa) and the functional properties of corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 44.02% was obtained under the specific extraction conditions, such as microwave power of 143.13 W, ethanol concentration of 61.77% and extraction time of 3.39 min. The maximum electron donating ability (EDA) was found as 45.85% at the conditions of 143.55 W microwave power, 27.52% ethanol concentration and 4.86 min extraction time. The maximum inhibitory effect on tyrosinase was 65.40% at 132.29 W, 36.47% and 7.62 min. The maximum superoxide dismutase (SOD)-like activity was 69.84% under the extraction conditions of 99.41 W, 8.47% and 7.13 min. Based on superimposition of four dimensional RSM with respect to extraction yield, electron donating ability and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of 0$sim$120 W, ethanol concentration of 70$sim$80% and extraction time of 2$sim$10 min.
