Effects of Extrusion Process Variables on Quality Properties of Wheat-Ginseng Extrudates

Figures & data

Table 1 Effects of extrusion process variables on the expansion ratio (ER), water absorption index (WAI), and water solubility index (WSI) of wheat-ginseng extrudates

Extrusion process variables
Feed moisture (%, wb)	Screw speed (rpm)	Temperature ^a (°C)	ER	WAI (g/g)	WSI (g/g)
25	200	110	2.23e	8.04cd	0.09ijk
30	200	110	2.11f	8.47b	0.08kl
35	200	110	1.99g	8.73a	0.06m
25	300	110	1.92ij	7.28gh	0.13e
30	300	110	1.89j	7.67f	0.12g
35	300	110	1.85k	7.86de	0.09ijk
25	200	120	2.45c	7.31gh	0.11gh
30	200	120	2.25e	7.92d	0.09ijk
35	200	120	1.97gh	8.21c	0.08kl
25	300	120	1.99g	6.91i	0.19c
30	300	120	1.99g	7.17h	0.13ef
35	300	120	1.94hi	7.38g	0.10hi
25	200	130	2.51b	6.70jk	0.12g
30	200	130	2.24e	7.31gh	0.09ij
35	200	130	1.98g	7.92d	0.07lm
25	300	130	1.98g	6.53k	0.23b
30	300	130	1.97gh	7.22gh	0.18d
35	300	130	1.97gh	7.21gh	0.11g
25	200	140	2.81a	6.70jk	0.12fg
30	200	140	2.30d	7.28gh	0.09jkl
35	200	140	2.13f	7.68ef	0.07lm
25	300	140	1.99g	6.56k	0.26a
30	300	140	1.99g	6.81ij	0.19cd
35	300	140	1.96gh	7.14h	0.13ef
Values with different letters within the same column differ significantly (P < 0.05).
^aTemperature: zone 5 (nearest exit die) barrel temperature.

Figure 1 Rapid Visco Analyzer pasting curves of a non-extruded wheat flour (WF)-ginseng powder (GP) blend (10% GP, w/w), and a wheat-ginseng extrudate (WGE) extruded at 30% feed moisture, 200 rpm screw speed, and 110°C zone 5 barrel temperature. Viscosity reported in rapid visco units (RVU).

Table 2 Effects of extrusion process variables on peak viscosity (PV), transition peak temperature (T _p ), and transition enthalpy (ΔH) of wheat-ginseng extrudates

Extrusion process variables
Feed moisture (%, wb)	Screw speed (rpm)	Temperature ^a (°C)	PV (RVU ^b )	Tp (°C)	ΔH (J/g)
25	200	110	118.9ef	167.8cd	2.65ijk
30	200	110	138.0d	170.3b	3.70fgh
35	200	110	206.1a	172.3a	1.75jk
25	300	110	56.3kl	158kl	6.00ab
30	300	110	62.8k	163.4ef	5.04cde
35	300	110	111.8fgh	164.0e	2.72ij
25	200	120	113.9efg	166.1d	3.94fgh
30	200	120	121.3e	167.9cd	4.56def
35	200	120	176.5b	168.7bc	3.43ghij
25	300	120	44.7mn	160.5hij	3.98fgh
30	300	120	55.6kl	161.8fghi	5.89abc
35	300	120	97.1i	162.3efgh	3.90fgh
25	200	130	112.5fg	162.4efg	3.76fgh
30	200	130	110.1gh	162.9efg	3.78fgh
35	200	130	159.4c	163.9e	3.81fgh
25	300	130	38.3no	156.2m	2.57jk
30	300	130	55.9kl	159.9j	5.39bcd
35	300	130	83.7j	160.2ij	3.53ghi
25	200	140	78.2j	161.5ghij	5.41bcd
30	200	140	103.9hi	162.6efg	3.49ghij
35	200	140	138.4d	163.6ef	4.37efg
25	300	140	36.3o	153.7n	3.42hij
30	300	140	49.0lm	156.2lm	6.60a
35	300	140	62.8k	159.7jk	4.55def
Values with different letters within the same column differ significantly (P < 0.05).
^aTemperature: zone 5 (nearest exit die) barrel temperature.
^bRVU: Rapid Visco Units.

Figure 2 Differential scanning thermograms of a wheat-ginseng extrudate (WGE) extruded at 30% feed moisture, 300 rpm screw speed, and 140°C zone 5 barrel temperature, and a non-extruded wheat flour (WF) and ginseng powder (GP) blend (10% GP, w/w).

Table 3 Pearson's coefficients of correlation (r) among quality properties [expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), peak viscosity (PV), transition peak temperature (T _p ), and transition enthalpy (ΔH)] of wheat-ginseng extrudates and system variables [specific mechanical energy (SME) and product temperature (PT)]

ER	WAI	WSI	PV	Tp	ΔH	SME	PT
ER	−0.22	−0.18	0.13	0.17	0.05	−0.63***	0.27
WAI		−0.76***	0.82***	0.88***	−0.38	−0.45*	−0.71***
WSI			−0.82***	−0.81***	0.23	0.69**	0.47*
PV				0.86***	−0.52**	−0.79***	−0.39
Tp					−0.42*	−0.67**	−0.67**
ΔH						0.31	0.24
SME							−0.02
PT
*, **, ***Significantly different at the 5%, 1%, and 0.1% levels, respectively.