THESIS - ROC CH ... - FINAL - resubmission.pdf - University of Guelph

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from 114 to -67°C when the moisture content increased from 0 to 35%. The 11S fraction ranged from 160 to -17°C with moisture content between 0 and 40%. Processing temperatures ranging from 60°C to 180°C have been previously employed for soy protein extrusion (Prudencio- Ferreira and Areas 1993; Zhang et al. 2001). During extrusion, high shear has shown to increase temperature and torque resulting in material degradation and excessive cross-linking (Otaigbe et al. 1999). This is thought to be caused by a reduction in activation energy from shear facilitating the crosslinking reactions (Pommet et al. 2005; Redl et al. 2003). As a result, the screw speed with torque and mass flow rate is closely associated to the success for protein film extrusion. Screw speeds of 20 to 200 rpm have been used for successful extrusion of soy protein films (Prudencio-Ferreira and Areas 1993; Zhang et al. 2001). With ideal extruding parameters, the unfolded proteins could then re-orientate in the direction of flow and crosslinks could be achieved before the polymer melt exits the die to form film (Prudencio-Ferreira and Areas 1993; Redl et al. 1999b). The crosslinks formed however would increase Tg and thus would require the use of a plasticizer to impart flexibility in the resulting extruded materials. Plasticizer molecules enable chain mobility by intermeshing within the protein matrix to disrupt forces holding chains together (Di Gioia and Guilbert 1999). Common plasticizers used for biopolymers include monosaccharides, oligosaccharides, polyols, lipids, and derivatives (Sothornvit and Krochta 2005). However, it seems that the use of glycerol with water has been the most widely studied (Chao et al. 2010; Chen et al. 2008; Chen et al. 2005; Chen and Zhang 2005; Cunningham et al. 2000; Hernandez-Izquierdo et al. 2008; Kokoszka et al. 2010; Pommet et al. 2003; Redl et al. 1999a; Su et al. 2010; Zhang et al. 2001). Water is a natural plasticizer and combined with glycerol, soy protein has been extruded with success (Prudencio-Ferreira and Areas 1993; Ralston and Osswald 2008; Zhang et al. 2001). 8
Ralston (2008) investigated the extrusion of SPI tubes with and without cellulose fibers through an annular die. With the base SPI formulation having moisture levels below 15%, bubble formation was prevalent yielding inacceptable shape and surface finish extrudates. However, by increasing the moisture concentration between 15 to 20%, successful tube extrusion was achieved. The barrel temperatures from hopper to the die were 60, 70, 80, and 95°C, and the screw speed was between 6 to 18 rpm. With the addition of fiber, a lubricant was needed to yield extrudate with similar qualities. No reports on performance were documented in Ralston’s studies. In terms of direct extrusion of soy protein into film form, only one study by Zhang et al. (2001) has ever reported close success. However, the study did not provide detail findings on the morphology of the films, i.e., whether there were surface disruptions or bubbling within the film. In their study, a mixture of SPI, water and glycerol was extruded at 120 to 160°C barrel temperatures and screw speeds ranging from 20 to 25 rpm, yielding sheets with thicknesses between 0.35 to 1.5 mm. Zhang et al. (2001) reported that the processability of SPI was heavily dictated by plasticizer content. At low concentrations of glycerol, processing was difficult resulting in brittle films. At glycerol concentrations between 20 to 30 parts by weight, coherent SPI films that were flexible were obtained. Further increase in the plasticizer concentration led to decreased mechanical strength. The plasticizing effect of water and glycerol are thought to improve chain mobility of the SPI films by decreasing the chain-chain interactions within the soy protein matrix, such as hydrogen bonding, dipole-dipole, charge-charge, and hydrophobic interactions. 9
Page 1 and 2: A Study on the Extrusion of Soy Pro
Page 3 and 4: ACKNOWLEDGEMENTS My research would
Page 5 and 6: 4.3.9 Statistical Analysis.........
Page 7 and 8: LIST OF TABLES Table 2.1: Compariso
Page 9 and 10: Figure 5.2: Light optical microscop
Page 11 and 12: 1.0 INTRODUCTION The production of
Page 13 and 14: einforcement material. Research int
Page 15 and 16: via centrifugation into four fracti
Page 17: zones are synonymous to feeding, tr
Page 21 and 22: onding between hydroxyl groups and
Page 23 and 24: Table 2.2: Summary of cellulose par
Page 25 and 26: through the use of enzymes have pro
Page 27 and 28: matrix such as soy protein (Wang et
Page 29 and 30: 4) Explore the extraction process f
Page 31 and 32: 4.3 METHODS 4.3.1 SAMPLE PREPARATIO
Page 33 and 34: a Figure 4.2: a) Schematic of extru
Page 35 and 36: length at break by the initial grip
Page 37 and 38: 4.4 RESULTS AND DISCUSSION 4.4.1 SP
Page 39 and 40: Further experiments were carried ou
Page 41 and 42: Figure 4.5: Film with rough texture
Page 43 and 44: extrusion screw to continuously bre
Page 45 and 46: stopped which fixes the spherical s
Page 47 and 48: 4.4.3 MECHANICAL PROPERTIES Mechani
Page 49 and 50: Elongation at break (%) Figure 4.10
Page 51 and 52: Table 4.5: Water vapor permeability
Page 53 and 54: 4.4.5 FTIR ANALYSIS The main absorb
Page 55 and 56: 4.4.6 CONCLUSION The extrusion of S
Page 57 and 58: 5.3 METHODS 5.3.1 CELLULOSE EXTRACT
Page 59 and 60: For mechanical treatments, the obta
Page 61 and 62: initial soy biomass; SNF and SMF. T
Page 63 and 64: compiled by Moon et al. (2011), thi
Page 65 and 66: RSH: 5min HPH: 20 passes, 4000 - 60
Page 67 and 68: SMF micrographs, the presence of fi
Page 69 and 70:
process as described. However, it m
Page 71 and 72:
a peak at 22.6° is representative
Page 73 and 74:
chemical and mechanical treatment h
Page 75 and 76:
6.3 METHODS 6.3.1 SAMPLE PREPARATIO
Page 77 and 78:
6.3.3 FILM CONDITIONING Similar to
Page 79 and 80:
increased in size. At fiber concent
Page 81 and 82:
6.4.2 MORPHOLOGY AND STRUCTURE Due
Page 83 and 84:
SEM images of the cryo-fractured su
Page 85 and 86:
Table 6.1: Mechanical properties of
Page 87 and 88:
cellulose and SPI. This high interf
Page 89 and 90:
concentrations at isolated sites. A
Page 91 and 92:
Similar to Section 4.4.5, dominatin
Page 93 and 94:
Further analysis of the Amide II ba
Page 95 and 96:
specimens that have been cryo-crush
Page 97 and 98:
crushing. Conversely, this could al
Page 99 and 100:
7.0 EXPLORATORY WORK WITH TIO 2 NAN
Page 101 and 102:
7.3.2 COMPOUNDING AND EXTRUSION Com
Page 103 and 104:
smaller size of P90, the ability to
Page 105 and 106:
Table 7.1: Mechanical Strength of T
Page 107 and 108:
Modulus of Elasticity (MPa) 120 110
Page 109 and 110:
(21 nm) particle was seen to have a
Page 111 and 112:
7.4.3 MECHANICAL PROPERTIES OF TIO2
Page 113 and 114:
Tensile Strenght (MPa) 12 11 10 9 8
Page 115 and 116:
Modulus of Elasticity (MPa) 200 180
Page 117 and 118:
8.0 CONCLUSIONS AND RECOMMENDATIONS
Page 119 and 120:
The viability of introducing a comp
Page 121 and 122:
acting as a coupling agent for furt
Page 123 and 124:
Cherian BM, Leao AL, Souza SFD, Tho
Page 125 and 126:
Kacurakova M, Capek P, Sasinkova V,
Page 127 and 128:
Pääkkö M, Ankerfors M, Kosonen H
Page 129:
Wang N, Ding E, Cheng R (2008) Prep
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THESIS - ROC CH ... - FINAL - resubmission.pdf - University of Guelph

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