- 學位論文
超音波快速萃取芭樂中抗氧化成份之研究
Study on antioxidant activity of extracts from guava by ultrasonic
摘要
芭樂在台灣是一種廣泛栽培的水果，其芭樂葉與果實都含有抗氧化效果的成份，芭樂茶與果實近年來是台灣廣泛流行的抗氧化物質，然而，關於芭樂葉、果實與樹枝的抗氧化活性研究較少，因此本研究主要利用超音波萃取芭樂葉、果實與樹枝的抗氧化成分，顯示芭樂果實與樹枝的抗氧化能力較芭樂葉弱，另外，研究以還原能力、DPPH自由基捕捉能力、螯合亞鐵離子能力與總酚含量來判斷萃取物之抗氧化能力，並探討總酚含量與抗氧化能力之相關性，另外，利用超音波萃取芭樂葉之有效成分，探討不同萃取條件對總酚含量之影響，研究發現萃取條件在50%的超音波輸出功率下，萃取溶劑添加50%乙醇於70℃下萃取7 分鐘，總酚含量可達11.26 mg/g、DPPH捕捉能力為83.4 %，於562 nm波長下可測得亞鐵離子螯合能力之吸光度為0.526，於700 nm波長下可測得還原力之吸光度為3.924。
並列摘要
Guava (Psidium guajava L.) is widely cultivated and its fruit is popular in Taiwan. The leaves and skin of the fruit have greater effects. Guava tea, the infusion of dried guava fruit and leaves, has recently become popular as a antioxidants in Taiwan. However, information concerning the antioxidant activity of guava leaves, fruit and branches extracts is unavailable. The objectives of this study were to study the antioxidant activity and effects of guava leaf, fruit and branches extracts by means of ultrasonic. In the present work, the antioxidant activity and effects of guava leaf, fruit and branches extracts by means of ultrasonic. In reducing power, DPPH radical-scavenging activity, ferrous ion chelating activity and total phenol experiments, the guava fruit and branches extracts exhibited weaker antioxidant effects than did the leaf extracts. The optimum condition for the extracts of guava leaf under the ultrasonic was as follows: volume ratio of water to ethanol is 1:1 and reaction time for 7 minutes at 70℃, we found there are more reducing power (Absorbance at 700 nm:3.924), DPPH radical-scavenging activity (83.4%), ferrous ion chelating activity (Absorbance at 562 nm: 0.526) and total phenol (11.26 mg/g) from guajava leaves extraction.