Optimization of Hydrothermal and Diluted Acid Pretreatments of Tunisian Luffa cylindrica (L.) Fibers for 2G Bioethanol Production through the Cubic Central Composite Experimental Design CCD: Response Surface Methodology

Table 6

The regression coefficients and for, respectively, Δ total and reducing sugars concentrations calculated for hydrothermal pretreatment of Luffa cylindrica biomass.

Regression coefficients	Factors and interactions
	Squared effect term	16.1811	11.2770
	Temperature	−0.6586	−0.2952
	Reaction time	2.0452	−0.4051
	Temperature^2	−4.0547	−0.7991
	Reaction time^2	1.3913	−0.0687
		−0.3982	−0.1878