Table 1.

Coded level of independent variables in experimental design¹⁾

Coded units	Arg	Met	Gly
−2	0.67	0.17	0.33
−1	0.83	0.25	0.67
0	1.00	0.33	1.00
1	1.17	0.42	1.33
2	1.33	0.50	1.67

¹⁾The content (w/v) was g, % of each additive per 100 mL of the mixture of enzymatic hydrolysates of soy sauce residue and defatted soybean (1:1 ratio, v/v).