Abstract:The DPPH radical scavenging activities was used as the main indicator of the antioxidant capacity of ultrasonic-assisted ethanol extracts from fruit of Carica papaya in different condition.Effects of extraction temperature,extraction time and extraction ultrasonic power on antioxidant activities of ethanol extracts from fruit of Carica papaya were studied.The maximum of clearance to DPPH was used as evaluating criteria.The best extracting condition was optimized by single factor and the orthogonal experiments.The content of total polysaccharide,total flavonoids and total polyphenols in these ethanol extracts were determined.The relationship among the content of total polysaccharide,total flavonoids,total polyphenols and the DPPH radical scavenging activities in these ethanol extracts was studied.Through orthogonal experiments,the optimal extraction conditions were determined: extraction time 30 min,extraction temperature 40℃,extraction ultrasonic power 400W.The influence degree of three factors on the extraction condition was the extraction time > the extraction temperature > the extraction ultrasonic power.No notable relationship among the content of total polysaccharide,total flavonoids,total polyphenols and the DPPH radical scavenging activities in these ethanol extracts was found.