Table 5.
The fitted quadratic model in terms of coded variables for Y₁, Y₂ and Y₃ responses

Response	Second order polynomial equation	R2
Total phenolic content	Y1 = – 142.407500 + 2.854650 X1 + 3.587350 X2 + 0.197367 X3 – 0.020490 X1 2 + 0.006000X1X2 – 0.031990 X2 2 + 0.001250 X1X3 + 0.008417 X2X3 – 0.007471X3 2	0.7293
DPPH radical scavenging activity	Y2 = – 427.675000 + 5.704250 X1 + 7.862000 X2 – 0.311417 X3 – 0.031550 X1 2 – 0.009250X1X2 – 0.054300 X2 2 – 0.002333 X1X3 + 0.008750 X2X3 – 0.00117X3 2	0.7836
Antimicrobial activity	Y3 = – 128.625000 + 3.070000 X1 + 0.817500 X2 – 0.244167 X3 – 0.019500 X1 2 – 0.002500X1X2 – 0.004500 X2 2 + 0.004167 X1X3 – 0.000778X3 2	0.8885