Table 4.

Estimated coefficients of the fitted quadratic polynomial equations for dependent variables based on the results of t-statistic.

Parameters	Y 1		Y 2		Y 3
	Coefficient	p-Value	Coefficient	p-Value	Coefficient	p-Value
Constant	37.5	0.000	2.5333	0.000	4.600	0.000
X 1	−6.5	0.000	−0.4725	0.000	0.660	0.005
X 2	6.7	0.000	−0.6755	0.000	0.945	0.001
X 1 X 1	4.6	0.003	0.1646	0.031	−1.013	0.002
X 2 X 2	−2.1	0.058	0.3896	0.001	−1.063	0.001
X 1 X 2	−3.0	0.034	−0.0500	0.481	−0.100	0.630

X₁, A/(B + C); X₂, B/C; A, water; B, starch syrup; C, soy sauce; Y₁: hardness (×1000 N/m²), Y₂: salinity (g/100 g), Y₃: sensory taste (points).