Optimization of Fura Production Using Response Surface Methodology

Figures & data

Table 1 Independent variables and levels used for central composite rotatable design. ¹

		Coded variable level x i
Variable	Symbols	−1.68(∝)	−1	0	1	1.68(∝)
Cooking time (min)	X1	13.2	20	30	40	46.8
Hydration time (hr)	X2	0.32	1	2	3	3.68
Water added (ml)	X3	3.2	10	20	30	36.8
^1Transformation of coded variable (x i) levels to uncoded variables (Xi) levels could be obtained from X1 = 10x 1 + 30; X2 = x 2 + 2; X3 = 10x 3 + 20.

Table 2 Central composite rotatable design arrangement and responses

	Independent variable ^a			Response variable ^b
Design points	Cooking time(X1)	Hydration time(X2)	Water added(X3)	Shear stress (Y1) (kN/m^2)	Shear strength (Y2) (kN/m^2)	Hardness (Y3) (kN)
1	−1	−1	−1	6.4	7.1	85.8
2	−1	1	−1	6.7	17.8	209.6
3	−1	−1	1	7.0	4.5	50.0
4	−1	1	1	11.6	12.8	130.1
5	1	−1	−1	3.5	5.2	47.1
6	1	1	−1	8.1	10.9	144.2
7	1	−1	1	6.0	3.8	38.7
8	1	1	1	7.6	3.1	35.2
9	−1.68	0	0	10.5	4.8	56.2
10	1.68	0	0	10.1	13.4	165.3
11	0	−1.68	0	10.0	8.6	102.0
12	0	1.68	0	10.6	19.7	241.5
13	0	0	−1.68	5.2	11.1	135.8
14	0	0	1.68	5.2	5.7	67.0
15	0	0	0	7.9	7.0	91.6
16	0	0	0	8.0	4.8	56.3
17	0	0	0	7.9	6.5	71.8
^aCoded symbols and levels of independent variables refer to Table 1.
^bAverage value of triplicate determinations except design points 15 to 17.

Figure 1 Improved fura production process.[4]

Table 3 Regression coefficient of predicted quadratic polynomial model for the three response variables

Coefficient	Shear stress	Shear strength	Hardness
Linear
β0	6.4635	6.4476	77.0670
β1	−0.5404	−0.2819	−0.8948
β2	0.8554	3.2050*	40.0638*
β3	0.5685	−1.9658*	−26.6115*
Quadratic
β11	0.7350	0.5064	5.0487
β22	0.7291	2.2841*	26.6646*
β33	−1.0782	0.2465	1.7237
Interaction
β12	0.0900	−1.6381*	−11.9455*
β13	−0.3733	−0.3285	−2.1212
β23	0.3205	−1.4423	−22.2044
*Significant at 0.05 level.

Figure 2 Response surface for the effects of flour hydration time and water added during pounding on the shear stress of fura.

Figure 3 Response surface for the effects of flour hydration time and water added during pounding on the shear strength of fura.

Figure 4 Response surface for the effects of flour hydration time and water added during pounding on the hardness of fura.

Jideani , V.A. 2005 . Characteristics of local pearl millet (Pennisetum glaucum) grains for fura production . Nigerian Food Journal , 23 : 193 – 204 .

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