Lynne Wong's PhD thesis

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4 0 Hailwood-Horrobin Reconstituted cane 4 0 Hailwood-Horrobin Reconstituted dry leaf 4 0 Hailwood-Horrobin Reconstituted green leaf EMC/% db 2 0 EMC/% db 2 0 EMC/% db 2 0 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 4 0 GAB Reconstituted cane 4 0 GAB Reconstituted dry leaf 4 0 GAB Reconstituted green leaf EMC/% db 2 0 EMC/% db 2 0 EMC/% db 2 0 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1. 0 1. 2 a w 30°C 45°C 55°C 60°C Figure 5.15. Comparison of the calculated and predicted EMC data for reconstituted cane stalk, dry leaf and green leaf of variety R 570 aged 52 weeks by the Hailwood-Horrobin and GAB models at 30, 45, 55 and 60 o C (Lines represent data predicted by the isotherm models). 235
CHAPTER 6. PROPERTIES OF THE SORBED WATER IN SUGAR CANE FIBRES In a review on moisture sorption isotherm characteristics of food products, Al-Muhtaseb et al. (2002) quoted that all types of water in a biological system exist as free or bound water. With type II isotherm as exhibited by the sugar cane component parts (Section 5.6.4.3), most authors (Singh et al., 2006, Arslan and Toğrul, 2005) divide the isotherm into three regions. The first, low water activity a w region (0.05 – 0.20) is indicative of strongly bound water, at the intermediate water activity region (0.20 – 0.60), water molecules which are less firmly bound, and in the region of high water activity (a w ≥ 0.6) excess water is present in macro-capillaries or as part of the fluid phase in high moisture materials. This water exhibits nearly all the properties of bulk water and thus is capable of acting as a solvent. The water in these three regions has also been termed non-freezable bound water, freezable bound water and free water. The water in the first region is strongly held by hydrogen bonds formed with the hydrophilic groups on the surface of the fibre and is not removable by drying in a vacuum. This was observed in this work that despite stringent drying, some moisture still remained in the fibres. This water is termed ‘non-freezable’ because it is frequently impossible to observe crystallisation or melting. The second type of bound water is less strongly held and does exhibit crystallisation and melting. Because of the bipolar nature of the water molecule, these water molecules form the multilayers by aligning themselves above those bonded to the hydroxyl groups of the fibres and form hydrogen bonds to produce hydrated layers. The water in the third region exists in the larger voids and capillaries, and essentially acts as bulk water. Water binds to the amorphous and not the crystalline part of the cellulose, it is known that water molecules directly attached to the hydroxyl group in the amorphous region are nonfreezing (Hatakeyama et al., 2000). In the case of cotton cellulose, the maximum amount of bound water of cellulose fibre corresponds to that where one hydroxyl group in the amorphous region attracts about one water molecule. Hailwood and Horrobin (1946) called the fraction of a polymer molecule which is inaccessible to water molecule to form a monohydrate the “crystalline” portion of the fibres.
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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
Page 237 and 238: After measuring the EMC of dry corn
Page 239 and 240: approached, that is, either by adso
Page 241 and 242: Table 5.4. Water activity (a w ) of
Page 243 and 244: 5.6.3 Procedure to determine equili
Page 245 and 246: 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: Table 5.33. Parameters of the Hailw
Page 291 and 292: where m is the equilibrium moisture
Page 297 and 298: 6.2 THE NUMBER OF ADSORBED MONOLAYE
Page 299 and 300: 6.3 TOTAL SOLID SURFACE AREA AVAILA
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
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Anon. (1985b). Laboratory manual fo
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Blanchi R.H. and A.G. Keller (1952)
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Day D.L. and G.L. Nelson (1965). De
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Heyrovsky J. (1970). Determination
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Kuhn I.J. (1964). A new theoretical
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Madamba P.S., R.H. Driscoll and K.A
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Prinsen Geerligs, H.C. (1897). Stud
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Sing K.S.W., D.H. Everett, R.A.W. H
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Van der Pol C., C.M. Young and K. D
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Lynne Wong's PhD thesis

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