Research Article

Optimization Conditions of Ultrasound-Assisted Extraction for Phenolic Compounds and Antioxidant Activity from Rubus alceifolius Poir Leaves

Table 2

Results of the ANOVA for the response surface quadratic model.

SourceTotal phenolic content (TPC)Antioxidant activity (ABTS)
Parameter estimateSSDFMS value valueParameter estimateSSDFMS valuevalue

Model16.10221.72924.63548.27<0.000121.16445.05949.4535.03<0.001
0.7333.60513.6057.060.0321.068.9518.956.340.04
-1.3012.777112.7825.040.001-2.758.16158.1641.2<0.001
0.2650.460810.46080.9040.374-0.250.49510.4950.350.573
-1.236.051616.051611.8570.0108-1.185.5915.593.960.087
-2.8930.636130.63760.028<0.0001-4.9096.14196.1468.1<0.001
-1.356.47716.47712.6910.009-2.1318.23118.2312.920.0008
-2.8633.817133.81866.261<0.0001-4.0970.28170.2849.78<0.0001
-3.5854.842154.842107.456<0.0001-4.3178.14178.1455.350.0001
-3.7656.295156.295110.303<0.0001-4.418218258.090.0001
Residual3.57370.5119.8871.41
LOF2.66930.88973.9390.1096.7732.262.90.166
0.9840.97
Adj 0.9640.95
Pred 0.8040.75
C.V5.877.85

Df: degree of freedom; SS: sum of squares; MS: mean square; : coefficient of determination; Adj: adjusted ; Predicted : Pred ; indicates statistical significance. stands for insignificant differences ().