Structural Properties of Corn-Legume Based Extrudates as a Function of Processing Conditions and Raw Material Characteristics

Figures & data

Figure 1 The lack of fit (S _R ) and standard experimental error (S _E ) as a function of the number of parameters.

Table 1 Extrusion conditions and material characteristics

Extrusion conditions	Minimum	Maximum
Extrusion temperature (°C)	150	230
Feed rate (kg/h)	2.52	6.84
Screw speed (rpm)	150	250
Materials characteristics
Feed moisture content (kg/100 kg wb)	13	19
Corn/legume ratio	10	90

Table 2 Chemical composition of raw materials (g/100g)

	Protein	Lipids	Total carbohydrates	Dietary fibre	Sugar
Corn	6	1	83	2	1
Chickpea	22	7	58	11	11
Mexican bean	23	1	60	15	2
White bean	23	1	60	15	2
Lentil	28	1	57	30	5

Figure 2 Measurement flowchart.

Table 3 Experimental and predicted porosity of extrudates

	Extrusion Conditions & Material Characteristics				Porosity		Standard Deviation
Material	C (%)	X (% wb)	T (°C)	τ (s)	ε (−)	ε i (−)	S R (−)
Corn/Chickpea	10	16	150	36	0.556	0.553	0.003
	50	16	150	28	0.613	0.618	0.005
	50	16	150	36	0.632	0.635	0.004
	50	16	150	40	0.640	0.643	0.003
	50	16	150	49	0.667	0.659	0.008
	50	16	150	58	0.669	0.672	0.003
	10	13	200	38	0.700	0.703	0.003
	10	14.5	200	38	0.692	0.690	0.002
	10	16	200	39	0.674	0.679	0.004
	10	17.5	200	39	0.670	0.668	0.002
	10	19	200	40	0.663	0.659	0.004
	50	13	200	38	0.804	0.801	0.003
	50	14.5	200	38	0.792	0.789	0.003
	50	16	200	28	0.748	0.746	0.002
	50	16	200	30	0.750	0.753	0.003
	50	16	200	39	0.775	0.776	0.001
	50	16	200	50	0.800	0.798	0.002
	50	16	200	55	0.814	0.808	0.006
	50	16	200	58	0.816	0.813	0.003
	50	17.5	200	39	0.760	0.764	0.004
	50	19	200	40	0.757	0.755	0.001
	90	13	200	38	0.850	0.844	0.006
	90	14.5	200	38	0.826	0.828	0.002
	90	16	200	39	0.808	0.815	0.006
	90	17.5	200	39	0.805	0.802	0.003
	90	19	200	40	0.788	0.791	0.003
	10	16	230	40	0.744	0.741	0.003
	50	16	230	28	0.820	0.818	0.002
	50	16	230	31	0.828	0.829	0.001
	50	16	230	40	0.847	0.854	0.008
	50	16	230	50	0.879	0.876	0.003
	50	16	230	58	0.891	0.892	0.001
Corn/Mexican Bean	10	16	150	30	0.696	0.697	0.001
	50	16	150	25	0.737	0.739	0.002
	50	16	150	26	0.742	0.740	0.002
	50	16	150	26	0.742	0.740	0.002
	50	16	150	26	0.742	0.740	0.002
	50	16	150	26	0.742	0.740	0.002
	50	16	150	30	0.745	0.746	0.001
	50	16	150	30	0.745	0.746	0.001
	50	16	150	35	0.750	0.754	0.004
	50	16	150	40	0.765	0.761	0.004
	50	16	150	40	0.765	0.761	0.004
	50	16	150	40	0.765	0.761	0.004
	50	16	150	48	0.772	0.770	0.002
	10	13	200	31	0.786	0.781	0.005
	10	14.5	200	32	0.760	0.764	0.004
	10	16	200	32	0.757	0.749	0.008
	10	17.5	200	32	0.730	0.736	0.006
	10	19	200	33	0.728	0.724	0.004
	50	13	200	31	0.843	0.837	0.006
	50	14.5	200	32	0.814	0.818	0.004
	50	16	200	25	0.794	0.790	0.004
	50	16	200	28	0.795	0.796	0.001
	50	16	200	32	0.802	0.803	0.000
	50	17.5	200	32	0.794	0.789	0.005
	50	19	200	33	0.775	0.777	0.001
	90	13	200	31	0.863	0.859	0.004
	90	14.5	200	32	0.837	0.840	0.003
	90	16	200	32	0.831	0.823	0.007
	90	17.5	200	32	0.814	0.809	0.005
	90	19	200	33	0.792	0.796	0.004
	10	16	230	33	0.776	0.780	0.004
	50	16	230	32	0.802	0.803	0.000
	50	16	230	32	0.802	0.803	0.000
	50	16	230	45	0.824	0.821	0.003
	50	16	230	45	0.824	0.821	0.003
	50	16	230	48	0.825	0.824	0.001
Corn/White Bean	10	16	150	33	0.783	0.791	0.008
	50	16	150	28	0.815	0.815	0.000
	50	16	150	33	0.818	0.821	0.003
	50	16	150	36	0.825	0.824	0.001
	50	16	150	45	0.835	0.831	0.004
	50	16	150	53	0.835	0.836	0.001
	10	13	200	35	0.859	0.860	0.001
	10	14.5	200	35	0.842	0.838	0.004
	10	16	200	36	0.814	0.819	0.004
	10	17.5	200	36	0.805	0.801	0.004
	10	19	200	36	0.785	0.786	0.001
	50	13	200	35	0.900	0.901	0.001
	50	14.5	200	35	0.871	0.878	0.007
	50	16	200	28	0.848	0.849	0.001
	50	16	200	36	0.860	0.858	0.002
	50	16	200	42	0.860	0.863	0.003
	50	16	200	51	0.870	0.870	0.000
	50	16	200	53	0.872	0.871	0.001
	50	17.5	200	36	0.843	0.840	0.004
	50	19	200	36	0.823	0.823	0.000
	90	13	200	35	0.910	0.917	0.007
	90	14.5	200	35	0.890	0.894	0.004
	90	16	200	36	0.878	0.872	0.006
	90	17.5	200	36	0.860	0.854	0.006
	90	19	200	36	0.837	0.837	0.001
	10	16	230	37	0.834	0.835	0.001
	50	16	230	28	0.859	0.867	0.008
	50	16	230	37	0.874	0.876	0.002
	50	16	230	45	0.886	0.883	0.003
	50	16	230	53	0.898	0.889	0.009
Corn/Lentil	10	16	150	29	0.691	0.693	0.002
	50	16	150	25	0.743	0.746	0.002
	50	16	150	29	0.746	0.753	0.007
	50	16	150	40	0.759	0.768	0.010
	50	16	150	45	0.780	0.774	0.006
	10	13	200	31	0.769	0.762	0.007
	10	14.5	200	31	0.750	0.746	0.004
	10	16	200	32	0.727	0.730	0.004
	10	17.5	200	32	0.723	0.717	0.006
	10	19	200	33	0.702	0.705	0.003
	50	13	200	31	0.834	0.829	0.006
	50	14.5	200	31	0.801	0.810	0.009
	50	16	200	25	0.777	0.781	0.004
	50	16	200	28	0.782	0.787	0.005
	50	16	200	32	0.795	0.794	0.001
	50	16	200	37	0.804	0.802	0.002
	50	16	200	45	0.813	0.811	0.001
	50	17.5	200	32	0.774	0.779	0.006
	50	19	200	33	0.764	0.766	0.003
	90	13	200	31	0.861	0.854	0.007
	90	14.5	200	31	0.842	0.836	0.006
	90	16	200	32	0.817	0.818	0.002
	90	17.5	200	32	0.798	0.803	0.005
	90	19	200	33	0.796	0.790	0.006
	10	16	230	33	0.751	0.749	0.002
	50	16	230	25	0.793	0.800	0.007
	50	16	230	33	0.807	0.814	0.007
	50	16	230	33	0.807	0.814	0.007
	50	16	230	40	0.830	0.824	0.006
	50	16	230	45	0.835	0.830	0.005

Table 4 Results of parameter estimation

	ε 0	n T	n τ	n X	n C	S R	S E
Corn/chickpea	0.863	0.661	0.117	−0.170	0.083	0.032	0.104
Corn/mexican bean	0.904	0.236	0.064	−0.200	0.043	0.032	0.067
Corn/white bean	0.974	0.142	0.041	−0.244	0.029	0.140	0.014
Corn/lentil	0.907	0.165	0.062	−0.214	0.052	0.132	0.022

Figure 3 Porosity of extrudates as a function of residence time and temperature (CP: corn/chickpea; CM: corn/mexican bean; CB: corn/white bean; CL: corn/lentil).

Figure 4 Porosity of extrudates as a function of feed moisture content and corn to legume ratio (CP: corn/chickpea; CM: corn/mexican bean; CB: corn/white bean; CL: corn/lentil).

Figure 5 Comparative figures of porosity for all extrudates (CP: corn/chickpea; CM: corn/mexican bean; CB: corn/white bean; CL: corn/lentil). a. Porosity as a function of residence time; b. porosity as a function of corn/legume ratio; c. porosity as a function of temperature; and d. porosity as a function of feed moisture content.

Figure 6 Comparative figures of expansion ratio for all extrudates (CP: corn/chickpea; CM: corn/mexican bean; CB: corn/white bean; CL: corn/lentil). e. Expansion ratio as a function of residence time; f. expansion ratio as a function of corn/legume ratio; g. expansion ratio as a function of temperature; and h. Expansion ratio as a function of feed moisture content.

Table 5 True density

	True density, ρp, (kg/m)
Corn/chickpea	1703 ± 387
Corn/mexican bean	1400 ± 107
Corn/white bean	1561 ± 134
Corn/lentil	1392 ± 61