2.8. Statistical analysis
All data collected from MAE extraction experiments were centred by using three parallel measurements of mean ± SD. The data of RSM were analysed using Statistical Analysis System (SAS version 9.0, SAS Institute Inc., Cary, North Carolina, USA) and used to design central composite rotatable design and analyse the experimental data. Data from the quadratic general rotary design were analysed by multiple regressions. Fischer’s test was used to determine the type of model equation, while the student’s t-test was performed for the determination of statistical significance of regression coefficients. P value