Study on optimized ethanol extraction conditions for NO scavenging activity components from daylily flower by response surface methodology

• Main Authors: Hung-Mei Liu, 劉虹每
• Other Authors: Wen-Dee Chiang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/22817826264582168035

碩士 === 東海大學 === 食品科學系 === 101 === The aim of this research was first to screen daylily flower with high nitric oxide (NO) scavenging components from ethanol extracts of five growth stages of daylily flower sources including 3, 6, 8, 10 cm bud and flower by measuring their anti-inflammatory activity in term of NO scavenging and its components including total phenolic compounds (TPC), total flavonoids (TF) and 11 kinds of phenolic compounds. Flower stage showed significantly higher NO scavenging than the other stages (p <0.05) up to 63.38%. TPC and TF content of flower stage were 22.4 mg GAE / g dry weight and 4.66 mg quercetin equivalent / g dry weight, respectively, which also showed significantly higher than the other stages (p <0.05). Furthermore, caffeic acid, epigallocatechin gallate (EGCG), epicatechin(EC), chlorogenic acid, rutin content of flower stage were 9.60, 140.75, 91.71, 33.06 and 43.14 mg/100 g dry weight, respectively, which also reveal notably higher than other stages (p <0.05). All the above phenolic compounds are positively correlation with anti-inflammatory activity. Finally, optimum extraction conditions of high NO scavenging and high TPC content from flower stage were investigated by response surface methodology (RSM). The optimum extraction conditions for both high NO scavenging and high TPC were ethanol concentration of 75 %, extraction temperature of 60 °C as well as extraction time of 2.75 h. Each F-value for lack of fit was not significant (p>0.05), so the second order model was appropriate for the response surface. In addition, each model had a satisfactory of R2 (0.9319-0.9381) and was verified experimentally.