Optimization of ultrasonic extraction of proanthocyanidins from egg jujube by response surface methodology

The extraction of proanthocyanidins from egg jujube was investigated by the single experiments and response surface methodology.On the basis of single factor tests, the method of the central composite experimental design ( BOX-Behnken) was used to optimal of ultrasound-assisted extraction of proanthocyanidins form egg jujube by factors and three levels.The results indicated that the extractive conditions were optimized as follows: ultrasonic treatment time of 16 min, ultrasonic power of 618 W, ultrasonic temperature of 65 ℃ and the ratio of material to solvent of 1 ∶ 21 ( g/m L) .Under these conditions, the yield of Procyanidins from egg jujube was 1.82%. Antioxidant activities in egg jujube of the proanthocyanidins indicates that proanthocyandins of egg jujube had strong scavenging effects against DPPH radicals, ·OH radicals and reductiion force was significant, it was not lower than that of V_C.