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 5

The regression coefficients for Δ total sugars concentration calculated for diluted acid pretreatment of Luffa cylindrica biomass.

Regression coefficients	Factors and interactions
	Squared effect term	4.8221
	Temperature	0.3821
	Reaction time	0.1193
	Acid concentration	−0.4087
	Temperature^2	0.9075
	Reaction time^2	−1.0283
	Acid concentration^2	−0.8120
		−0.4230
		0.8708
		0.0872