Abstract
The extracts from 66 species of fruits and vegetables cultivated in Okinawa region of Japan were prepared by sequential extraction with acetone at 30°C and 80% ethanol solution at 80°C, and their polyphenol contents and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities were measured. The total polyphenol contents of both extracts from edible parts varied in the range of 0.35 to 142.04μmol-gallic acid equivalent/g-fresh weight. The plants with higher polyphenol content showed a consistent tendency to exhibit higher radical-scavenging activity. Sapodilla (Manikara zapora), canistel (Pouteria campechiana), guava (Psidium guajava) and starfruit (Averrhoa carambola), originally came from the tropical zone, showed both higher level of polyphenol content and radical-scavenging activity, and they contained proanthocyanidin. The following higher group composed of bayberry (Myrica rubra), red cabbage (Brassica oleracea), suizenjina (Gynura bicolor) and purple-fleshed sweet potato (Ipomoea batatas), which contained anthocyanins. Nigana (Crepidiastrum lanceolatum), botanboufuu (Peucedanum japonicum) and nishiyomogi (Artemisia Indica), cooked only in Okinawa region within the country, also showed a high polyphenol content and radical-scavenging activity. In addition, there were some extracts from inedible parts of fruits, which possessed almost the same or higher level of polyphenol content and radical-scavenging activity, compared to their edible parts.
