Table 1.
Experimental ranges and values of the independent variables in the central composite design for manufacturing of the capsule type- fish roe analogs

Symbol	Independent variables	Coded levels
		-2	-1	0	+1	+2
X1	Sodium alginate concentration (%, w/v)	1.2	1.5	1.8	2.1	2.4
X2	Calcium chloride concentration (%, w/v)	0.5	1.0	1.5	2.0	2.5
X3	Agitation speed of calcium chloride solution (rpm)	150	220	290	360	430
X4	Dropping height (cm)	5	10	15	20	25