Lynne Wong's PhD thesis

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Table 6.2. Properties of sorbed bound water and sorbent of cane components at different temperatures. Number of adsorbed monolayers, N o Density of bound water/g cm -3 Bound or non-freezable water/% Surface area/m 2 g solids -1 Temperature/ o C 30 45 55 60 30 45 55 60 30 45 55 60 30 45 55 60 52 weeks Stalk fibre 6.55 5.55 4.89 4.76 0.14 0.16 0.18 0.18 6.02 4.90 4.34 4.17 192.3 183.5 130.3 114.1 Stalk pith 6.51 5.52 4.42 4.01 0.12 0.14 0.17 0.20 5.24 4.22 3.41 3.15 190.9 167.9 148.8 143.5 Rind fibre 6.70 5.51 4.66 4.48 0.14 0.16 0.20 0.20 6.30 5.00 4.30 3.97 189.9 195.2 131.1 95.3 Rind fines 6.45 5.57 5.06 5.08 0.15 0.16 0.19 0.19 6.10 5.06 4.85 4.85 161.2 172.8 113.3 118.7 Top fibre 6.34 5.24 4.76 4.29 0.13 0.16 0.17 0.19 5.25 4.33 3.91 3.47 198.4 157.3 114.8 121.8 Dry leaf fibre 6.87 5.48 4.99 4.51 0.13 0.16 0.17 0.18 6.03 4.79 4.34 3.75 191.6 147.7 150.2 94.9 Dry leaf fines 6.64 5.71 5.37 4.73 0.13 0.15 0.16 0.18 5.62 4.95 4.76 4.08 269.9 153.0 131.4 119.0 Green leaf fibre 5.94 5.31 4.77 5.00 0.15 0.16 0.18 0.17 5.17 4.52 4.06 4.29 202.2 160.8 130.3 124.7 Green leaf fines 6.08 5.16 4.63 4.83 0.14 0.16 0.18 0.18 5.21 4.31 3.80 4.11 182.4 139.6 119.4 122.6 Reconstituted cane stalk 6.57 5.55 4.69 4.48 0.14 0.16 0.19 0.19 5.90 4.78 4.11 3.88 178.9 162.2 125.7 108.7 Reconstituted dry leaf 6.79 5.57 5.14 4.59 0.13 0.16 0.17 0.18 5.87 4.86 4.49 3.87 227.5 139.3 126.8 100.8 Reconstituted green leaf 5.97 5.26 4.71 4.86 0.15 0.16 0.18 0.18 5.18 4.44 3.95 4.14 165.2 145.0 121.5 115.4 36 weeks Stalk fibre 6.05 5.09 5.22 4.79 0.15 0.17 0.17 0.19 5.53 4.50 4.69 4.41 147.7 141.3 125.4 141.7 Stalk pith 6.12 4.97 4.45 4.88 0.14 0.16 0.18 0.17 5.10 3.91 3.56 3.96 189.9 163.6 138.5 126.1 Rind fibre 7.13 5.19 5.22 5.24 0.14 0.18 0.18 0.18 6.86 4.84 4.84 4.98 166.8 161.5 124.3 141.3 Rind fines 6.41 5.58 5.27 6.04 0.15 0.17 0.19 0.17 6.13 5.18 5.23 6.08 155.5 160.1 122.9 133.5 Top fibre 5.97 5.23 4.56 4.76 0.14 0.16 0.18 0.18 5.03 4.28 3.78 4.07 195.2 161.2 114.8 104.1 Dry leaf fibre 6.10 5.71 5.79 4.47 0.14 0.15 0.15 0.19 5.33 4.87 5.07 3.83 165.8 158.3 158.3 31.2 Dry leaf fines 6.57 5.18 5.53 5.34 0.13 0.16 0.16 0.17 5.81 4.36 4.75 4.74 176.4 157.3 182.4 142.7 Green leaf fibre 6.24 5.12 5.06 4.19 0.14 0.17 0.17 0.19 5.56 4.36 4.42 3.35 160.5 144.9 144.9 70.5 Green leaf fines 6.36 5.26 5.12 4.55 0.14 0.16 0.17 0.18 5.67 4.51 4.40 3.78 154.8 150.9 117.9 104.1 Reconstituted cane stalk 6.56 5.20 5.00 5.11 0.14 0.17 0.18 0.18 6.04 4.61 4.51 4.68 165.4 132.8 120.1 129.6 Reconstituted dry leaf 6.27 5.52 5.69 4.69 0.14 0.15 0.15 0.18 5.50 4.67 4.95 4.03 165.4 143.6 145.0 76.7 Reconstituted green leaf 6.27 5.17 5.07 4.28 0.14 0.16 0.17 0.19 5.59 4.40 4.40 3.46 156.5 137.4 131.0 78.6 245
6.3 TOTAL SOLID SURFACE AREA AVAILABLE FOR HYDROPHILIC BINDING IN ADSORPTION The solid surface area was determined from the monolayer moisture content by using the following equation (Mazza and Le Maguer, 1978): A = m o N A A m /m w = 35.42 m o where A is the solid surface area (m 2 g solids -1 ), m o is the monolayer moisture content (% db), m w is the molar mass of water (18.02 g mol -1 ), N A is Avogadro’s number (6.022 x 10 23 molecules mol -1 ), and A m is the area of a water molecule (1.06 x 10 -19 m 2 molecule -1 ). Since the GAB was found to be a good fit to the experimental adsorption data, the m o value calculated from the GAB equation was used to estimate the total solid surface area A. The results of the total solid surface area A calculated are also presented in Table 6.2. In general, A decreased with increased temperature. Stalk pith and dry leaf fines were among those components which had high surface area for hydrophilic binding. Arslan and Toğrul (2005) found in their study of moisture adsorption of macaroni, the total available surface area for hydrophilic binding decreases with an increase in temperature. This is also true for most sugar cane component parts aged 52 and 36 weeks except for rind fibre and rind fines of both ages, top fibre, dry leaf fibre and green leaf fines aged 52 weeks and dry leaf fines aged 36 weeks. The values found for the sugar cane fibres vary from 100 – 200 m 2 g solids -1 , which are much lower than the 200 – 300 m 2 g solids -1 found for macaroni by Arslan and Toğrul (2005), and similarly for quinoa grains by Tolaba et al. (2004), but higher than in goat meat (Singh et al., 2006), kheer (Kumar et al., 2005) and chhana podo (Rao et al., 2006), all about 80 m 2 g solids -1 . As the temperature increased from 30 to 60 °C, the number of adsorbed monolayers, the percentage of bound water and the surface area of adsorbent decreased. This may be due to the reduction in sorption of water with increasing temperature in the low water activity range. Noguchi (1981) reported that hydrophobic hydration of biopolymers melts off rapidly as the temperature increases. 246
Page 1 and 2:
THE BRIX-FREE WATER CAPACITY AND SO
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dissolved and hydrated waters, and
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ACKNOWLEDGEMENTS I am particularly
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Page 1.5 THE DELETERIOUS EFFECTS OF
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Page 2.2 THE PHENOMENON OF BRIX-FRE
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Page 3.4.3.3 Cane tops 83 3.4.4 Cha
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4.3.3 Temperature at which Brix-fre
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4.6.1 Materials 143 4.6.1.1 Samples
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CHAPTER 6. PROPERTIES OF THE SORBED
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APPENDIX 3. CALCULATIONS LEADING TO
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LIST OF FIGURES Page Figure 1.1. Fi
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Figure 3.1. Glucose and fructose an
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Figure 5.11. Residual plots for the
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total adsorbed water (m) and the pr
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Table 2.18. Moisture content in sug
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Page Table 4.4. Results of the dete
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Page Table 4.24. Analysis of varian
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Page Table 5.13. Table 5.14. Equili
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Table 6.3. Heat of sorption of the
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GLOSSARY OF TERMS Absorption is the
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Filterability of a raw sugar is mea
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Sorption is the generic term used w
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LIST OF MAIN SYMBOLS Symbol Descrip
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s c s Slope of Caurie I isotherm pl
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number of 255, and cane land covere
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Nouvelle Mon In Trésor ustrie and
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Figure 1.3. Cane sampling by core s
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In Mauritius, most of the sugar fac
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are: cane tops, dry and green leave
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1.4 TRENDS IN CANE QUALITY RECEIVED
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campaign was launched to encourage
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The level of extraneous matter in c
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In Australia (Cargill, 1976), cane
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The effect of soil on factory perfo
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leaves increased the level of impur
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• From 1976 to 1980, when the pro
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Clerget purity of molasses 40 Clerg
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CHAPTER 2. IMPACT OF EXTRANEOUS MAT
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Since the extrapolated purity of mo
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Figure 2.1. Jeffco cutter grinder.
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2.1.4 Results The analytical result
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Table 2.3. Analytical results of re
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Table 2.5. Composition of dry trash
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Table 2.7. Predicted factory perfor
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Boiling house recovery 91.0 89.8 89
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0 5 10 15 20 % EM in cane y = 0.572
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% EM in cane 0 5 10 15 20 0 -2 -4 -
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1 y = 0.020 (% D) R 2 = 1.00 = 0.03
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% EM in cane 0 5 10 15 20 0 -2 y =
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esulting in 0.015 unit sucrose loss
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2.2.1 Experimental procedure Cane m
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filter paper, rejecting the first f
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Table 2.9. Effect of increased addi
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Table 2.11. Effect of increased add
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Table 2.13. Effect of increased add
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various components such as stalk fi
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in the presence of dry leaves, if c
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Table 2.17. Moisture content in sug
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CHAPTER 3. SEPARATION OF THE SUGAR
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Table 3.1. It can be seen that the
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Table 3.2. Fibrous physical composi
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R 579 R 570 M 1557/70 M 1400/86 74
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loosen the fibre. The woody core is
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agitate the mixture in the pot, and
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Figure 3.7. Custom-built fibre-pith
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The extraction of fibres starting f
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pre-treatment in a Jeffco cutter-gr
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Figure 3.19. Stalk cake washed free
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not have many dry leaves attached t
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Table 3.5. Masses of cane samples a
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Table 3.7. Masses of cane samples a
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Table 3.9. Masses of cane component
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3 57.6 126.3 23.7 97.2 31.1 53.8 11
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Table 3.12. Material loss (%) from
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3.5.3 Fibre/pith ratios in cane com
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Table 3.15. Effect of extraneous ma
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Snow (1974) investigated the season
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from Figure 2.9 that the change in
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Table 3.18. Fibre % cane results by
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110
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(a). Dry leaf (b). Green leaf (c).
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dry fibre, or a factor, is used in
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Steuerwald (1912) applied sucrose s
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solution/fibre ratio was lowered fr
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leave some residual moisture on the
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instead of 150 g of 10° Brix sucro
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Table 4.2. Determination of Brix-fr
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Table 4.3. Comparison of Brix-free
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Table 4.4. Results of the determina
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In order to test for homogeneity of
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Table 4.7. Results of the repeat de
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The experiment was repeated with th
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e any residual moisture in the samp
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By means of the same technique, Won
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was still hot. Since the filter was
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value determined could be corrected
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Qin and White’s finding was confi
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A sample size of 3.5 g with 75 g co
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Figure 4.4. Fibre samples drying in
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- One large fibre sample (rind) of
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Table 4.18. Brix-free water values/
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Table 4.20. Brix-free water values/
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4.7.3 Statistical analysis It is es
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Table 4.23. Analysis of variance (B
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pointing out that at 52 weeks old,
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The crop of R 570 sampled in 2001 w
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4.7.4. Estimated Brix-free water co
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The main difference in the two sets
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Table 4.27. Predicted Brix-free wat
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4.8 SUMMARY AND CONCLUSIONS An anal
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component parts, and verify the Bri
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3) Thermodynamic, water in equilibr
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Langmuir (1916, 1917, 1918) propose
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to determine the moisture sorption
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Table 5.1. Some commonly used isoth
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Lomauro et al. (1985) found that wi
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and on agricultural products such a
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Bruijn (1963) studied the mass incr
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After measuring the EMC of dry corn
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approached, that is, either by adso
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Table 5.4. Water activity (a w ) of
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5.6.3 Procedure to determine equili
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5.6.4 Results and discussion An exa
Page 247 and 248: Table 5.8. Equilibrium moisture con
Page 249 and 250: Table 5.10. Equilibrium moisture co
Page 251 and 252: Table 5.12. Equilibrium moisture co
Page 253 and 254: 30 o C 45 o C 55 o C 60 o C Water w
Page 255 and 256: m/m of 96% activity, a w (g/100g dr
Page 257 and 258: vaporisation generally decreases fr
Page 259 and 260: 30 o C isotherm 45 o C isotherm 55
Page 261 and 262: 4 0 Stalk fibre 5 0 Stalk pith 5 0
Page 263 and 264: 5.6.4.4 Fitting of sorption models
Page 265 and 266: Table 5.19. Parameters of the sorpt
Page 275 and 276: Modified GAB Kuhn Iglesias - Chirif
Page 277 and 278: Table 5.28. Classification of resid
Page 279 and 280: Stalk fibre Stalk pith Rind fibre 4
Page 281 and 282: 5.6.4.5 Calculated EMC values of re
Page 283 and 284: Table 5.30. Calculated equilibrium
Page 285 and 286: m/m of 96% Table 5.32. Calculated e
Page 287 and 288: Table 5.33. Parameters of the Hailw
Page 289 and 290: CHAPTER 6. PROPERTIES OF THE SORBED
Page 291 and 292: where m is the equilibrium moisture
Page 297: 6.2 THE NUMBER OF ADSORBED MONOLAYE
Page 301 and 302: Thus, for each cane component of ea
Page 303 and 304: abscissa. For each moisture level (
Page 307 and 308: A similar procedure was followed to
Page 309 and 310: 10 0 Stalk fibre Stalk pith Rind fi
Page 311 and 312: Moreover, if T β > T hm the proces
Page 313 and 314: Table 6.5. Characteristic parameter
Page 315 and 316: Binding energy/kJ (kg mol) -1 2 0 0
Page 317 and 318: 6.8 CALCULATION OF BOUND WATER AND
Page 319 and 320: The values of K 1 , K 2 and W were
Page 321 and 322: Table 6.7. Separation of the total
Page 323 and 324: Table 6.7. (Contd.) Sample 30 o C 4
Page 325 and 326: 3 0 S talk fibre 4 0 Stalk pith 3 0
Page 327 and 328: 3 0 Reconstituted cane at 30 o C 3
Page 329 and 330: when water is added to dry wood, wh
Page 331 and 332: It is evident that in some cases ma
Page 333 and 334: The number of adsorbed monolayers,
Page 335 and 336: Data in Tables 2.9 and 2.11 show th
Page 337 and 338: particular fibre is systematically
Page 339 and 340: Anon. (1985b). Laboratory manual fo
Page 341 and 342: Blanchi R.H. and A.G. Keller (1952)
Page 343 and 344: Day D.L. and G.L. Nelson (1965). De
Page 345 and 346: Heyrovsky J. (1970). Determination
Page 347 and 348: Kuhn I.J. (1964). A new theoretical
Page 349 and 350:
Madamba P.S., R.H. Driscoll and K.A
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Prinsen Geerligs, H.C. (1897). Stud
Page 353 and 354:
Sing K.S.W., D.H. Everett, R.A.W. H
Page 355 and 356:
Van der Pol C., C.M. Young and K. D
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Lynne Wong's PhD thesis

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