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4.2 Moisture Content Table3. Results of the moisture, nitrogen and ash content of chitosan samples are presented in Table 3. Proximate Analysis of Crawfish and Commercial Chitosans (dry weight basis) Sample Moisture (%) Nitrogen (%) Ash (%) DCMPA 0.3 (0.35) c 8.23 (0.02) b 0.2 (0.07) a DMCPA 0.6 (0.21) c 8.09 (0.01) b 0.9 (0.99) a DMPCA 0.6 (0.21) c 8.01 (0.05) b 0.4 (0) a DMPAC 0.6 (0.21) c 6.91 (0.05) d 1.6 (1.98) a DPMCA (control) 0.7 (0.42) c 8.03 (0.06) b 0.3 (0.07) a Vanson 75 4.5 (0) a 7.53 (0.14) c 1.4 (0.05) a Sigma 91 3.5 (0.07) b 8.50 (0.21) a 1.8 (0.05) a Numbers in parentheses are standard deviations. Means with different letters in each column are significantly different (p < 0.05). DCMPA=decolorized, demineralized, deproteinized, deacetylated; DMCPA= demineralized, decolorized, deproteinized, deacetylated; DMPCA= demineralized, deproteinized, decolorized, deacetylated; DMPAC= demineralized, deproteinized, deacetylated, decolorized; and DPMCA= deproteinized, demineralized, decolorized, deacetylated. Vanson75 and Sigma91 are commercial crab chitosans. The crawfish chitosan samples had a moisture content ranging from 0.3% to 0.7%. Commercial crab chitosans, Vanson75 and Sigma91, had a relatively higher moisture content, 4.5% and 3.5%, respectively, than the experimental samples. Chitosan is hygroscopic in nature (Khan et al., 2001), hence it is very possible that the two commercial samples were affected by moisture absorption during storage. According to Li (1992), commercial chitosan products contain less than 10% moisture content. 4.3 Nitrogen Content The nitrogen content of the crawfish chitosan samples varied between 6.91% and 8.23% on a dry basis compared with 7.53% to 8.50% for Vanson75 and Sigma91, respectively. With the exception of DMPAC (6.91%), DCMPA, DMCPA, DPMCA, and DMPCA (8.23%, 8.09%, 8.03%, and 8.01%, respectively) showed no significant differences (P >0.05) in nitrogen content, 44
ut the values were slightly higher than that (7.06% to 7.97%) reported by No and Meyers (1995) for chitosan from crab and shrimp shell on a dry basis. This probably is due to the presence of protein residues as mentioned by Rutherford and Austin (1978). Protein is bound by covalent bonds forming stable complex with chitin and chitosan. Thus, it is very difficult to achieve 100% deproteinization. Even with complete DP, nitrogen (7.06 to 7.97%; No et al., 1995) is still remained as chitosan has the amino (-NH2) group. 4.4 Ash Ash measurement is an indicator of the effectiveness of the demineralization (DM) step for removal of calcium carbonate. Elimination of the demineralization resulted in products having 31 – 36% ash (Bough et al., 1978). The ash content in chitosan is an important parameter. Some residual ash of chitosans may affect their solubility, consequently contributing to lower viscosity, or can affect other more important characteristics of the final product. A high quality grade of chitosan should have less than 1% of ash content (No et al., 1995). An ash content of less than 1% from crab chitosans has been reported by No and Meyers (1995). Table 3 also shows the ash content of crawfish chitosans compared with that of the commercial crab chitosans. Our crawfish chitosans contained less than 1% ash with a range of 0.2% to 0.9%, except for DMPAC with 1.6%. Commercial chitosan products contained less than 2.0% ash. 4.5 Degree of Deacetylation The degree of deacetylation of our crawfish chitosan samples ranged from 68% to 73% with an average of 71% (Table 4). According to No and Meyers (1995), DD of chitosan ranges from 56% to 99% with an average of 80%. Sample DCMPA (73%) had the highest DD, followed by DMPCA, DMCPA and DPMCA (71%, 70%, and 68%, respectively). The FTIR absorption 45
Page 1 and 2: PHYSICOCHEMICAL AND FUNCTIONAL PROP
Page 3 and 4: TABLE OF CONTENTS ACKNOWLEDGEMENTS
Page 5 and 6: LIST OF TABLES 1. Applications of C
Page 7 and 8: ABSTRACT Chitosan is made from chit
Page 9 and 10: CHAPTER 1 INTRODUCTION Chitosan is
Page 11 and 12: Crawfish shell as well as crustacea
Page 13 and 14: 5. Investigate the effect of deacet
Page 15 and 16: With regards to their chemical stru
Page 17 and 18: acetic acid. The second advantage i
Page 19 and 20: lower viscosity chitosan obtained f
Page 21 and 22: not deacetylated sufficiently to be
Page 23 and 24: 2.2.8 Emulsification Even though ch
Page 25 and 26: 2.2.10 Formation of Film Chitosan h
Page 27 and 28: Fortunately, the sequence of demine
Page 29 and 30: of the demineralization process. El
Page 31 and 32: 2.4 Factors Affecting Production of
Page 33 and 34: (0.841-0.177 mm) had no effect on t
Page 35 and 36: methods are those of Hackman (1954)
Page 37 and 38: degree of deacetylation, and molecu
Page 39 and 40: 2.6.3 In Medical In the study condu
Page 41 and 42: 2) DM (Demineralization) Depending
Page 43 and 44: analyze. The encapsulated sample wa
Page 45 and 46: and centrifuged at 10,000 rpm for 1
Page 47 and 48: with 0.03% Oil-Red-O biological sta
Page 49 and 50: CHAPTER 4 RESULTS AND DISCUSSION Re
Page 51: The shell was almost impossible to
Page 55 and 56: %DD values. Thus, accurate determin
Page 57 and 58: degradation of the chitosan structu
Page 59 and 60: treatment for deproteinization. In
Page 61 and 62: chitosan samples, we arbitrarily de
Page 63 and 64: Amongst the five types of oil used,
Page 65 and 66: - 0.5% chitosan solution only. Even
Page 67 and 68: showed 271 ml/g. All modified chito
Page 69 and 70: At 0.1% concentration of chitosan,
Page 71 and 72: CHAPTER 5 SUMMARY AND CONCLUSIONS T
Page 73 and 74: REFERENCES Alimuniar and Zainuddin.
Page 75 and 76: pigment concentration in oil extrac
Page 77 and 78: Jeon, Y.J., Shahidi, F., and Kim, S
Page 79 and 80: Utilization of Louisiana Crawfish P
Page 81 and 82: Ogawa, S., Decker, E., McClememts D
Page 83 and 84: Smith, J.P. Simpson, B.K. and Morri
Page 85 and 86: APPENDIX A. DATA OF PHYSICOCHEMICAL
Page 87 and 88: APPENDIX 5. Degree of Deacetylation
Page 89 and 90: Bulk density (g/ml) APPENDIX 9. Bul
Page 91 and 92: WBC (%) 1200.0 1000.0 800.0 600.0 4
Page 93 and 94: APPENDIX 13. Emulsion Capacity Meas
Page 95 and 96: APPENDIX 15. Emulsion Viscosity Mea
Page 97 and 98: APPENDIX 18. DMPCA y = 33.471x + 9.
Page 99 and 100: APPENDIX 21. Vanson 75 y = 21.926x
Page 101 and 102: APPENDIX C. DATA OF DEGREE OF DEACE
Page 103 and 104:
APPENDIX 27. DPMCA(control) A1655 =
Page 105 and 106:
APPENDIX D. DATA OF AMOUNTS OF OIL
Page 107:
VITA The author was born in Taegu,
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