Dynamic Viscoelastic Behavior of High Pressure Treated Soybean Protein Isolate Dispersions

Figures & data

Figure 1 DSC thermograms of SPI dispersions: a control 10%; b pressuruized 15% at 350 and 550 MPa for 15 minutes.

Figure 2 Typical mechanical spectra of pressurized 15% SPI dispersion at 20°C.

Figure 3 Effect of high pressure on elastic modulus of SPI dispersion at selected concentration.

Figure 4 Effect of pressure on viscous component of SPI dispersion at selected concentration.

Table 1 Regression parameters of pressurized SPI dispersions

	G′				G″
	b1	A1	R^2	SE	b2	A2	R^2	SE
10%
Control	0.117	9.73	0.987	0.019	0.208	4.87	0.988	0.034
350 MPa	0.145	6.06	0.840	0.093	0.266	1.90	0.974	0.061
450 MPa	0.218	5.81	0.867	0.125	0.295	2.47	0.975	0.068
550 MPa	0.294	5.50	0.884	0.156	0.312	3.05	0.971	0.076
650 MPa	0.296	5.46	0.988	0.048	0.392	3.43	0.985	0.072
15%
Control	0.070	432.7	0.997	0.006	0.127	62.8	0.970	0.033
350 MPa	0.080	353.3	0.998	0.005	0.145	40.1	0.991	0.020
450 MPa	0.079	526.7	0.999	0.003	0.143	56.3	0.990	0.021
550 MPa	0.090	481.6	0.997	0.007	0.141	72.4	0.988	0.022
650 MPa	0.089	421.2	0.996	0.008	0.153	36.6	0.992	0.020
20%
Control	0.078	1115	0.998	0.005	0.128	150	0.985	0.023
350 MPa	0.094	866.7	0.999	0.002	0.115	133	0.995	0.012
450 MPa	0.093	1008	0.999	0.003	0.116	153	0.994	0.013
550 MPa	0.092	1149	0.999	0.004	0.117	179	0.994	0.013
650 MPa	0.099	968.1	0.999	0.004	0.130	162	0.993	0.014

Figure 5 Pressure effect on viscoelastic properties of 15% SPI dispersions.

Figure 6 Post-high pressure changes in phase angle of SPI at 1 Hz.

Figure 7 Comparison of thermal (IH: 90°C for 30 minutes) and pressure effect (HP: 650 MPa for 15 minutes) on dynamic rheological parameters of 20% SPI dispersion.

Figure 8 (a) Native-PAGE patterns of SPI: Lane 1 & 5-control, 2 & 6- 350MPa, 3 & 7 550MPa, 4 & 8–650 MPa, M: standard marker; (b) SDS-PAGE profile of SPI: Lane 1 & 2-control; 3 & 4–350MPa, 5 & 6–550MPa, 7 & 8–650MPa, (M ) standard marker.