Optimization of Extracting Procyanidins from Litchi Pericarp by Orthogonal Test

OBJECTIVE To study the most effective condition of extracting procyanidins from Litchi pericarp( Huaizhi).METHODS Single factor experiments of extracting procyanidins from Litchi pericarp( Huaizhi) was carried out including ultrasonic power,extracting period,ethanol percentage,solvent p H,solid / liquid ratio and temperature. Orthogonal array design L27( 35) was carried out to find the most effective condition of extracting procyanidins. RESULTS The results showed that the most optimal extraction were found to be applying p H 6.0 70% ethanol to extract twice in 400 W ultrasonic power at 50 ℃ for 40 min with a solid /liquid ratio of 1 ∶15. The effect of 5 important variables on the extracting rate of proanthocyanidins followed decreasing order: ultrasonic power > extracting period > temperature > ethanol percentage > solid / liquid ratio. CONCLUSION Proanthocyanidins could be extracted more effectively from Litchi pericarp via the optimized extraction.