Development, Characterization, and Optimization of Protein Level in Date Bars Using Response Surface Methodology

Table 6

Regression coefficients for the models representing as a function of variations in the independent variables for hardness (firmness) of date bars and their respective 𝑅².

Terms of model equations	Days
	0	15	30	45	60	75	90
Constant	115.34	468.85	−204.7	31.03	−1022.0	−150.2	−564.9
𝑋	76.45	64.90	234.2	259.22	503.0	447.7	531.0
𝑌	87.03	182.37	535.8*	561.53	890.0	607.1	870.2
𝑋×𝑋	−6.46	−9.55	−20.3	−22.47	−41.0	−33.9	−41.5
𝑌×𝑌	−12.29	−28.92	−61.7*	−72.79	−105.0	−72.8	−110.2
𝑋×𝑌	−2.45	7.08	−7.8	−4.50	−6.0	−9.9	4.4
𝑅^2	90.6%	59.3%	85.6%	60.7%	63.3%	54.9%	57.6%