Functional and physical properties of sorghum-based extruded product supplemented with soy meal flour

Figures & data

Table 1. Experimental levels of the variables

Variables	Levels
	−1	0	1
S (%)	0	10	20
FM (%)	15	18	21
BT(^oC)	135	150	165

S = soy meal flour (%); FM = feed moisture content (%); BT = barrel temperature (^oC)

Table 2. Proximate composition and functional properties of sorghum and soy meal flour

Components	*Sorghum flour (debranned)	*Soy meal flour
Moisture (%)	7.1 ± 0.06	7.84 ± 0.04
Protein (%)	12.14 ± 0.11	49.08 ± 0.26
Fat (%)	3.25 ± 0.09	6.74 ± 0.01
Ash (%)	1.60 ± 0.17	6.46 ± 0.21
Fiber (%)	0.85 ± 0.02	5.30 ± 0.05
^1CHO (%)	74.06 ± 0.53	23.58 ± 0.02
WAI (g/g)	2.55 ± 0.04	2.71 ± 0.24
WSI (%)	2.76 ± 0.08	3.01 ± 0.18
WHC (g/g)	2.98 ± 0.11	3.26 ± 0.09

* = mean±SD of three replications; ¹ = Obtained by difference; CHO = carbohydrate (%); WAI = water absorption index (g/g); WSI = water solubility index (%); WHC = water holding capacity (g/g)

Figure 1. Extrudates processed from sorghum and soy meal flour at different processing conditions.

(A) 0% soy meal flour, 15% feed moisture and 165°C barrel temperature; (B) 0% soy meal flour, 15% feed moisture and 150°C barrel temperature; (C) 0% soy meal flour, 18% feed moisture and 165°C barrel temperature; (D) 10% soy meal flour, 15% feed moisture, 165°C barrel temperature; (E) 10% soy meal flour, 18% feed moisture, 165°C barrel temperature; (F) 10% soy meal flour, 18% feed moisture and 150°C barrel temperature; (G) 20% soy meal flour, 15% feed moisture and 165°C barrel temperature; (H) 20% soy meal flour, 18% feed moisture and 150°C barrel temperature; (I) 20% soy meal flour, 21% feed moisture and 150°C barrel temperature.

Table 3. Main effects of extrusion variables on product functional properties

Variable	n	* Functional properties
		WAI (g/g)	WSI (%)	WHC (g/g)
S (%)
0	18	6.05 ± 0.30^c	7.51 ± 0.07^c	7.82 ± 0.36^c
10	18	6.48 ± 0.40^b	7.90 ± 0.05^b	7.97 ± 0.18^b
20	18	7.27 ± 0.43^a	8.62 ± 0.09^a	8.51 ± 0.38^a
F.M (%)
15	18	6.26 ± 0.51^c	8.07 ± 0.49^a	8.05 ± 0.43^a
18	18	6.53 ± 0.55^b	8.01 ± 0.47^b	8.13 ± 0.37^a
21	18	7.02 ± 0.61^a	7.95 ± 0.47^c	8.13 ± 0.51^a
BT (ºC)
135	18	6.66 ± 0.63^a	7.97 ± 0.47^c	7.98 ± 0.34^b
150	18	6.65 ± 0.65^a	8.02 ± 0.48^b	7.94 ± 0.36^b
165	18	6.50 ± 0.65^b	8.04 ± 0.49^a	8.38 ± 0.47^a
Mean	54	6.60	8.01	8.10
CV		0.98	0.3	2.13

Values followed by the different letters within each variable in a column indicate significant difference (P < 0.05); S = soy flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); * mean±SD; n = number of observations; WAI = water absorption index (g/g); WSI = water solubility index (%); WHC = water holding capacity; CV = coefficient of variation

Table 4. Two way interaction effects of extrusion variables on functional properties of extrudates

S	BT	N	WAI (g/g)	WSI (%)	WHC (g/g)
0	135	6	6.10 ± 0.16^f	7.47 ± 0.03^h	7.88 ± 0.47^d
0	150	6	6.05 ± 0.39^fg	7.51 ± 0.06^g	7.59 ± 0.28^e
0	165	6	5.99 ± 0.35^g	7.56 ± 0.08^f	8.00 ± 0.18^cd
10	135	6	6.49 ± 0.48^d	7.89 ± 0.04^e	7.82 ± 0.09^d
10	150	6	6.66 ± 0.44^c	7.92 ± 0.04^d	7.93 ± 0.16^d
10	165	6	6.30 ± 0.21^e	7.89 ± 0.07^e	8.15 ± 0.12^bc
20	135	6	7.39 ± 0.19^a	8.56 ± 0.06^c	8.24 ± 0.19^b
20	150	6	7.22 ± 0.52^b	8.63 ± 0.08^b	8.31 ± 0.13^b
20	165	6	7.21 ± 0.56^b	8.68 ± 0.08^a	8.99 ± 0.16^a
DMRT (P value)			<0.0001**	<0.0001**	0.0007**
S	FM
0	15	6	5.74 ± 0.17^g	7.56 ± 0.06^f	7.76 ± 0.41^c
0	18	6	6.01 ± 0.08^f	7.53 ± 0.05^g	7.90 ± 0.23^bc
0	21	6	6.40 ± 0.11^d	7.45 ± 0.02^h	7.81 ± 0.46^bc
10	15	6	6.17 ± 0.09^e	7.96 ± 0.03^d	7.90 ± 0.10^bc
10	18	6	6.41 ± 0.41^d	7.89 ± 0.04^e	7.97 ± 0.17^bc
10	21	6	6.87 ± 0.25^c	7.86 ± 0.03^e	8.04 ± 0.25^b
20	15	6	6.87 ± 0.29^c	8.71 ± 0.07^a	8.48 ± 0.31^a
20	18	6	7.17 ± 0.13^b	8.61 ± 0.06^b	8.51 ± 0.34^a
20	21	6	7.78 ± 0.14^a	8.55 ± 0.05^c	8.55 ± 0.52^a
DMRT (P value)			0.0002**	0.0048 **	0.7815 ns
BT	FM
135	15	6	6.45 ± 0.62^d	8.02 ± 0.51^c	8.16 ± 0.25^cd
135	18	6	6.52 ± 0.61^d	7.97 ± 0.49^d	8.05 ± 0.20^cd
135	21	6	7.00 ± 0.60^b	7.93 ± 0.48^e	7.74 ± 0.42^e
150	15	6	6.13 ± 0.48^f	8.08 ± 0.52^b	7.75 ± 0.42^e
150	18	6	6.72 ± 0.52^c	8.02 ± 0.49^c	7.95 ± 0.31^de
150	21	6	7.09 ± 0.61^a	7.96 ± 0.50^d	8.12 ± 0.28^cd
165	15	6	6.18 ± 0.47^f	8.12 ± 0.53^a	8.23 ± 0.48^bc
165	18	6	6.36 ± 0.54^e	8.04 ± 0.51^c	8.38 ± 0.45^ab
165	21	6	6.96 ± 0.73^b	7.96 ± 0.52^d	8.54 ± 0.50^a
DMRT (P value)			<0.0001**	0.0197*	<0.0001**

Values followed by the different letters with in a column indicate significant difference (P < 0.05); DMRT = Duncan’s Multiple Range Test; ns = not significant (P > 0.05); *, ** = significant at 5% and 1% probability level, respectively; Tt = treatment number; S = defatted soy flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); n = number of observations; WAI = water absorption index (g/g); WSI = water solubility index; WHC = water holding capacity.

Table 5. Effect of extrusion variables on product functional properties

Processing conditions					*Functional properties
Tt	S (%)	BT (^oC)	FM (%)	n	WAI (g/g)	WSI (%)	WHC (g/g)
1	0	135	15	2	5.94 ± 0.06^no	7.50 ± 0.02^nm	8.13 ± 0.05^bcdef
2	0	135	18	2	6.06 ± 0.05^nm	7.48 ± 0.01^no	8.06 ± 0.17^cdefg
3	0	135	21	2	6.29 ± 0.03^jk	7.43 ± 0.01°	7.47 ± 0.75^ij
4	0	150	15	2	5.62 ± 0.06^p	7.57 ± 0.03^lk	7.31 ± 0.37^j
5	0	150	18	2	6.06 ± 0.02^nm	7.52 ± 0.02^lm	7.65 ± 0.09^hij
6	0	150	21	2	6.49 ± 0.02^hi	7.45 ± 0.01°	7.80 ± 0.02^fghi
7	0	165	15	2	5.65 ± 0.05^p	7.62 ± 0.01^k	7.83 ± 0.04^efgh
8	0	165	18	2	5.92 ± 0.05°	7.59 ± 0.03^k	8.00 ± 0.19^cdefg
9	0	165	21	2	6.41 ± 0.12^ij	7.46 ± 0.01^no	8.17 ± 0.04^bcde
10	10	135	15	2	6.18 ± 0.11^klm	7.92 ± 0.03^gh	7.91 ± 0.06^defgh
11	10	135	18	2	6.18 ± 0.04^klm	7.89 ± 0.05^hi	7.84 ± 0.02^efgh
12	10	135	21	2	7.10 ± 0.11^e	7.85 ± 0.04^ij	7.73 ± 0.00^ghi
13	10	150	15	2	6.10 ± 0.05^lm	7.96 ± 0.01^fg	7.78 ± 0.01^fghi
14	10	150	18	2	6.93 ± 0.08^f	7.92 ± 0.04^gh	7.89 ± 0.03^efgh
1 5	10	150	21	2	6.95 ± 0.08^f	7.89 ± 0.02^hi	8.12 ± 0.04^bcdef
16	10	165	15	2	6.12 ± 0.05^lk	7.98 ± 0.01^f	8.00 ± 0.00^cdefg
17	10	165	18	2	6.57 ± 0.01^lm	7.85 ± 0.01^ij	8.19 ± 0.06^bcde
18	10	165	21	2	6.22 ± 0.10^gh	7.84 ± 0.01^j	8.26 ± 0.03^bcd
19	20	135	15	2	7.24 ± 0.03^cd	8.63 ± 0.01^c	8.45 ± 0.06^b
20	20	135	18	2	7.30 ± 0.07^c	8.56 ± 0.02^d	8.25 ± 0.02^bcd
21	20	135	21	2	7.62 ± 0.06^b	8.50 ± 0.01^e	8.03 ± 0.01^cdefg
22	20	150	15	2	6.67 ± 0.04^g	8.72 ± 0.00^b	8.17 ± 0.05^bcde
23	20	150	18	2	7.16 ± 0.08^de	8.61 ± 0.03^c	8.32 ± 0.10^bc
24	20	150	21	2	7.82 ± 0.02^a	8.56 ± 0.03^d	8.43 ± 0.04^b
25	20	165	15	2	6.69 ± 0.04^g	8.77 ± 0.04^a	8.84 ± 0.01^a
26	20	165	18	2	7.04 ± 0.05^ef	8.68 ± 0.02^b	8.94 ± 0.00^a
27	20	165	21	2	7.89 ± 0.09^a	8.60 ± 0.05^cd	9.18 ± 0.00^a
Mean				54	6.60	8.01	8.10
CV					0.98	0.30	2.13
P value					<.0001	0.3184	0.6771

Values followed by the different letters with in a column indicate significant difference (P < 0.05); Tt = treatment number; S = soy flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); n = number of replications; WAI = water absorption index (g/g); WSI = water solubility index; WHC = water holding capacity; CV = coefficient of variation

Table 6. Main effects of extrusion variables on product physical properties

Variable	n	* Product physical property
		ER	SL(cm/g)	BD(g/cm^3)	H (N)
S (%)
0	18	2.16 ± 0.29^a	1.23 ± 0.22^a	0.24 ± 0.05^b	96.48 ± 16.64^b
10	18	2.08 ± 0.22^b	1.27 ± 0.23^a	0.25 ± 0.07^b	101.77 ± 13.09^b
20	18	1.76 ± 0.11^c	1.16 ± 0.07^b	0.36 ± 0.03^a	112.77 ± 11.86^a
F.M (%)
15	18	2.14 ± 0.30^a	1.26 ± 0.15^a	0.24 ± 0.08^a	93.14 ± 16.72^a
18	18	1.99 ± 0.26^b	1.28 ± 0.22^a	0.27 ± 0.07^b	103.61 ± 10.17^b
21	18	1.87 ± 0.20^c	1.12 ± 0.16^b	0.33 ± 0.04^c	114.28 ± 10.77^c
Temp (ºC)
135	18	1.87 ± 0.20^c	1.26 ± o.15^a	0.30 ± 0.07^a	109.67 ± 12.97^a
150	18	1.96 ± 0.23^b	1.31 ± 0.21^a	0.27 ± 0.09^b	101.25 ± 13.50^b
165	18	2.17 ± 0.30^a	1.09 ± 0.12^b	0.26 ± 0.07^b	100.11 ± 18.09^b
Mean	54	2.00	1.22	0.28	103.68
CV		4.20	8.85	8.29	8.44

Values followed by the different letters within each variable in a column indicate significant difference (P < 0.05); S = soy meal flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); n = number of observation; * = mean±SD; SL = specific length (cm/g); ER = expansion ratio; BD = bulk density (g/cm³); H = hardness (N); CV = coefficient of variation

Table 7. Two way interaction effects of extrusion variables on product physical properties

S	BT	n	SL (cm/g)	ER (cm/cm)	BD (g/cm^3)	H (N)
0	135	6	1.31 ± 0.14^abc	1.98 ± 0.23^c	0.26 ± 0.04^cd	103.10 ± 15.88^b
0	150	6	1.36 ± 0.16^ab	2.06 ± 0.23^c	0.23 ± 0.05^de	100.02 ± 15.85^b
0	165	6	1.03 ± 0.19^f	2.44 ± 0.15^a	0.22 ± 0.06^e	86.33 ± 15.72^c
10	135	6	1.26 ± 0.22^bcd	1.96 ± 0.09^c	0.27 ± 0.06^c	108.11 ± 8.28^ab
10	150	6	1.43 ± 0.25^a	2.06 ± 0.22^c	0.23 ± 0.09^de	100.13 ± 15.35^b
10	165	6	1.11 ± 0.08^ef	2.23 ± 0.24^b	0.24 ± 0.07^de	97.07 ± 14.16^b
20	135	6	1.20 ± 0.05^cde	1.67 ± 0.06^e	0.38 ± 0.01^a	117.79 ± 10.83^a
20	150	6	1.14 ± 0.08^def	1.78 ± 0.11^d	0.36 ± 0.03^ab	103.60 ± 11.08^b
20	165	6	1.13 ± 0.03^def	1.84 ± 0.10^d	0.33 ± 0.04^b	116.93 ± 9.29^a
DMRT (P value)			0.0035**	0.0008**	0.4888 ns	0.0169*
S	FM
0	15	6	1.28 ± 0.10^ab	2.38 ± 0.18^a	0.18 ± 0.02^f	80.10 ± 10.89^e
0	18	6	1.28 ± 0.27^ab	2.09 ± 0.31^cd	0.24 ± 0.03^d	98.75 ± 11.14^cd
0	21	6	1.14 ± 0.25^bc	2.00 ± 0.24^de	0.29 ± 0.02^c	110.61 ± 11.46^ab
10	15	6	1.35 ± 0.20^a	2.22 ± 0.24^b	0.20 ± 0.05^ef	92.02 ± 13.29^d
10	18	6	1.39 ± 0.23^a	2.11 ± 0.18^c	0.21 ± 0.03^e	100.91 ± 8.70^bcd
10	21	6	1.06 ± 0.08^c	1.92 ± 0.13^e	0.33 ± 0.03^b	112.39 ± 8.96^ab
20	15	6	1.15 ± 0.08^bc	1.82 ± 0.13^f	0.34 ± 0.04^b	107.31 ± 14.44^bc
20	18	6	1.15 ± 0.05^bc	1.78 ± 0.12^fg	0.35 ± 0.03^ab	111.18 ± 6.77^ab
20	21	6	1.17 ± 0.08^bc	1.69 ± 0.06^g	0.38 ± 0.01^a	119.84 ± 11.18^a
DMRT (P value)			0.0041**	0.0033**	<0.0001**	0.1516 ns
BT	FM
135	15	6	1.27 ± 0.08^bc	1.97 ± 0.24^c	0.28 ± 0.08^cd	102.73 ± 12.40^c
135	18	6	1.33 ± 0.18^ab	1.83 ± 0.19^d	0.30 ± 0.07^bc	107.14 ± 8.77^bc
135	21	6	1.18 ± 0.16^cd	1.81 ± 0.16^d	0.34 ± 0.05^a	119.13 ± 12.97^a
150	15	6	1.33 ± 0.23^ab	2.14 ± 0.25^b	0.23 ± 0.09^ef	87.25 ± 4.84^d
150	18	6	1.42 ± 0.24^a	1.95 ± 0.17^c	0.25 ± 0.08^de	102.25 ± 10.31^c
150	21	6	1.18 ± 0.09^cd	1.80 ± 0.11^d	0.34 ± 0.04^a	114.25 ± 7.14^ab
165	15	6	1.18 ± 0.09^cd	2.31 ± 0.33^a	0.22 ± 0.08^f	89.44 ± 24.59^d
165	18	6	1.08 ± 0.06^de	2.19 ± 0.28^b	0.25 ± 0.06^de	101.44 ± 12.06^c
165	21	6	1.01 ± 0.15^e	2.01 ± 0.26^c	0.32 ± 0.04^ab	109.45 ± 10.89^abc
DMRT (P value)			0.2210 ns	0.0613 ns	0.0659 ns	0.5141 ns

Values followed by the different letters with in a column indicate significant difference (P < 0.05); DMRT = Duncan’s Multiple Range Test; ns = non-significant (P > 0.05); *, ** = significant at 5 and 1% probability level, respectively; S = soy meal flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); n = number of replication; 1 = mean±SD; SL = specific length (cm/g); ER = expansion ratio; BD = bulk density (g/cm³); H = hardness (N); Tt = treatment number

Table 8. Effect of extrusion variables on product physical properties

Processing condition					Product physical property
Tt	S (%)	BT(^oC)	FM (%)	n	*SL(cm/g)	*ER (cm/cm)	*BD(g/cm^3)	**H(N)
1	0	135	15	2	1.28 ± 0.05^cdefg	2.22 ± 0.00^bcdef	0.21 ± 0.01^ijk	90.22 ± 4.25^fgh
2	0	135	18	2	1.34 ± 0.28^bcde	1.89 ± 0.29^ghij	0.28 ± 0.02^efgh	98.36 ± 0.91^cdefgh
3	0	135	21	2	1.32 ± 0.13^bcdef	1.82 ± 0.00^ghij	0.29 ± 0.03^defg	120.74 ± 15.57^ab
4	0	150	15	2	1.34 ± 0.14^bcde	2.33 ± 0.05^abc	0.18 ± 0.01^jk	82.99 ± 3.13^hi
5	0	150	18	2	1.50 ± 0.19^abc	1.96 ± 0.19^fghij	0.23 ± 0.02^ghij	106.99 ± 18.82^abcdefg
6	0	150	21	2	1.25 ± 0.06^cdefgh	1.89 ± 0.09^ghij	0.29 ± 0.01^defg	110.08 ± 3.54^abcdef
7	0	165	15	2	1.23 ± 0.11^cdefhg	2.60 ± 0.05^a	0.16 ± 0.01^k	67.09 ± 2.27^i
8	0	165	18	2	1.01 ± 0.01^ghi	2.43 ± 0.09^ab	0.22 ± 0.02^hijk	90.91 ± 2.55^efgh
9	0	165	21	2	0.85 ± 0.17^i	2.29 ± 0.10^bc	0.29 ± 0.03^defg	101.00 ± 3.32^bcdefgh
10	10	135	15	2	1.35 ± 0.04^bcde	1.99 ± 0.05^edfgh	0.25 ± 0.01^fghi	105.78 ± 9.62^hi
11	10	135	18	2	1.44 ± 0.14^abcd	1.95 ± 0.04^fghij	0.23 ± 0.01^ghij	109.84 ± 9.97^cdefgh
12	10	135	21	2	1.00 ± 0.06^hi	1.95 ± 0.20^fghij	0.34 ± 0.04^abcde	108.71 ± 11.55^abcdef
13	10	150	15	2	1.54 ± 0.20^ab	2.25 ± 0.21^bcde	0.17 ± 0.06^jk	87.83 ± 6.54^gh
14	10	150	18	2	1.62 ± 0.01^a	2.10 ± 0.01^cdefg	0.18 ± 0.00^ijk	95.47 ± 5.25^defgh
15	10	150	21	2	1.14 ± 0.08^efgh	1.82 ± 0.00^ghij	0.34 ± 0.03^abcde	117.11 ± 13.63^abc
16	10	165	15	2	1.17 ± 0.13^efgh	2.42 ± 0.22^ab	0.19 ± 0.06^ijk	82.46 ± 12.28^bcdefg
17	10	165	18	2	1.13 ± 0.02^efgh	2.28 ± 0.23^bcd	0.22 ± 0.04^hijk	97.41 ± 2.83^abcdef
18	10	165	21	2	1.05 ± 0.02^fghi	2.00 ± 0.13^edfgh	0.31 ± 0.04^bcdef	111.35 ± 2.87^abcdefg
19	20	135	15	2	1.20 ± 0.08^defgh	1.69 ± 0.10^ij	0.38 ± 0.02^ab	112.20 ± 12.14^abcde
20	20	135	18	2	1.20 ± 0.05^defgh	1.67 ± 0.08^j	0.39 ± 0.02^a	113.23 ± 6.42^abcd
21	20	135	21	2	1.22 ± 0.07^edfgh	1.66 ± 0.04^j	0.38 ± 0.00^a	127.95 ± 9.36^a
22	20	150	15	2	1.10 ± 0.10^efghi	1.85 ± 0.08^ghij	0.34 ± 0.00^abcde	90.95 ± 0.04^efgh
23	20	150	18	2	1.15 ± 0.04^efgh	1.79 ± 0.14^hij	0.35 ± 0.04^abcd	104.29 ± 2.12^bcdefg
24	20	150	21	2	1.16 ± 0.14^efgh	1.69 ± 0.09^ij	0.39 ± 0.01^a	115.57 ± 1.41^abcd
25	20	165	15	2	1.14 ± 0.06^efgh	1.92 ± 0.10^ghij	0.31 ± 0.05^cdef	118.77 ± 7.07^abc
26	20	165	18	2	1.12 ± 0.01^efgh	1.87 ± 0.03^ghij	0.33 ± 0.01^abcde	116.01 ± 5.80^abcd
27	20	165	21	2	1.14 ± 0.03^efgh	1.74 ± 0.01^hij	0.37 ± 0.01^abc	116.00 ± 18.38^abcd
Mean				54	1.22	2.00	0.28	103.68
CV					9.21	6.23	10.10	8.53

Values followed by the different letters with in a column indicate significant difference (P < 0.05); S = soy meal flour (%); BT = barrel temperature (°C); FM = feed moisture content (%); n = number of replication; * = mean±SD; SL = specific length (cm/g); ER = diametric expansion; BD = bulk density (g/cm³); H = hardness (N); Tt = treatment number; CV = coefficient of variation