. 2022 Jan 17;5:207–221. doi: 10.1016/j.crfs.2022.01.011

Table 5.

Regression coefficients, R², p-value of lack of fit, the significance probability (p-value, t-ratio) of regression coefficients in final reduced second-order polynomial models of the final reduced models.

Responses	ΔH (%, Y1)		ΔS (%, Y2)		Δ_Cp (%, Y3)
Coefficient	HIT1	HIT2	HIT1	HIT2	HIT1	HIT2
β₀	−1.43421	0.838606	0.023053	0.020568^a	0.096552	0.090432^a
β₁	0.00458	−0.001248	−0.000369	−0.000202	−0.000628	0.000334
β₂	0.11891	0.237095^a	0.000893	0.001140	−0.001313	–
β₃	0.34548	−0.100428	–	−0.002012	–	−0.020451^a
$β_{1}^{2}$	0.00032	−0.000227^a	0.000007	−0.000002	0.000014	−0.000022^a
$β_{2}^{2}$	0.00119	−0.016667^a	0.000016	−0.000057	0.000077^a	–
$β_{3}^{2}$	0.00668	−0.022102^a	–	−0.000203^a	–	−0.000365
β₁₂	−0.00160^a	−0.001892^a	−0.000022^a	−0.000013	−0.000049	–
β₁₃	–	0.004971^a	–	0.000061^a	–	0.000377^a
β₂₃	−0.01100^a	–	–	–	–	–
R²	0.618	0.953	0.478	0.907	0.374	0.898
p-value	0.018	0.000	0.026	0.000	0.196	0.000
Lack of fit (p-value)	0.064	0.162	0.621	0.284	0.051	0.362
Main effects (p-values)
X₁	0.951	0.895	0.722	0.190	0.111	0.629
X₂	0.134	0.005^a	0.374	0.311	0.083	–
X₃	0.247	0.147	–	0.072	–	0.001^a
Quadratic effects (p-values)
X₁₁	0.423	0.003^a	0.226	0.136	–	0.000^a
X₂₂	0.059	0.019^a	0.057	0.561	–	–
X₃₃	0.769	0.000^a	–	0.010^a	–	0.279
Interaction effects (p-values)
X₁X₂	0.027^a	0.040^a	0.026^a	0.329	0.039^a	–
X₁X₃	–	0.000^a	–	0.000^a	–	0.000^a
X₂X₃	0.041^a	–	–	–	–	–
Main effects (t-ratios)
X₁	−0.063	−0.136	−0.363	−1.396	1.303	0.494
X₂	1.618	3.469	1.063	1.063	1.110	–
X₃	1.224	−1.561	–	−1.994	–	−4.110
Quadratic effects (t-ratios)
X₁₁	0.831	−3.743	1.266	−1.609	–	−4.780
X₂₂	2.102	−2.753	2.075	−0.599	–	–
X₃₃	0.302	−5.256	–	−3.083	–	−1.125
Interaction effects (t-ratios)
X₁X₂	−2.558	−2.328	−2.487	−1.020	−1.223	–
X₁X₃	–	7.340	–	5.767	–	7.180
X₂X₃	−2.313	–	–	–	–	–
OP (X₁, X₂, X₃)
OP_HIT1 (68.5, 10, 2.56)	1.1060	–	0.0154	–	0.0683	–
OP_HIT2 (40, 1.56, 2,5)	–	0.7252	–	0.0100	–	0.0449

Abbreviation:β₀ is a constant, β_i, β_ii and β_ij are the linear, quadratic and interaction coefficients of the quadratic polynomial equation, respectively. i: Heating temperature generated via heat irradiation or heat ionization; ii: Time conducted for both treatments; ij: Mass of starting material for heat irradiation treatment or pH of buffer system for heat ionization.

Significant at p < 0.05.