*4.6. Statistical Analysis*

All of the analyses in the present study were performed in triplicate. XLSTAT for Excel 2021 version (Addinsoft, New York, USA) was used for statistical analysis of the data. In order to evaluate the significant differences (*p* < 0.05) among samples the *t*-test was used.

For the assessment of GP addition effects on WWF and pasta quality, mathematical modeling of the results was carried out by using the trial version of Design Expert software (Stat-Ease, Inc., Minneapolis, USA), by applying response surface methodology (RSM). The effect of GP level factor on the responses (ηmax, G\*, Co, C\*, Ch, F, CL, TPC, TDF and RS) was observed by using a D-optimal design with one factor varied at six levels (1, 2, 3, 4, 5, 6%) and three replications. The model's fitting was evaluated through a sequential Fisher test, coefficients of determination (*R* 2 ) and adjusted coefficient of determination (*Adj.-R*<sup>2</sup> ), at a 95% confidence level. The most suitable model was selected according to the highest *Adj.-R*<sup>2</sup> value.
