Optimization of ultrasound-assisted extraction of total phenol from betel (Areca catechu L.) nut seed and evaluation of antioxidant activity in vitro

Optimization of the ultrasound-assisted extraction technology for total phenol from betel (Areca catechu L.) nut seed was carried out. On the basis of one factor tests, the method of response surface analysis with 3 factors including extracting temperature, time and solvent-material ratio on the content of total phenol was adopted. The optimal extracting conditions are as follows: extraction temperature 58 degrees C, extraction time 42 min and solvent-material ratio 53 ml/g. The predicted value and measured value of total phenol was 164.74 mg catechin equivalents/g of betel nut seed (mg CE/g BNS) and 160.95 mg CE/g BNS under this condition, respectively. The results indicate that the obtained model developed by response surface methodology is feasible for practical prediction. The experiments of antioxidant activity showed that the betel nut seed extract presents the strong antioxidant activities to the DPPH and ABTS radical and the EC50 is 113.42 and 105.69 mu g/ml, respectively.