physicochemical and functional properties of crawfish chitosan as ...

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peeling waste during recovery of edible tail meat that makes up 15% of the total product. The waste residue representing 85% of the biomass has traditionally been discharged in landfill dumping sites without pretreatment (Rout, 2001). While much research has been done with chitosan extraction from crab shell, limited information is available on the extraction possibilities with crawfish shell waste. The humongous waste from crawfish particularly in Louisiana represents an outlet economic potential for the state. Previous studies demonstrated that crawfish and crustacean wastes, as well as organically-rich shellfish processing streams in general, can no longer be considered as disposable “waste” products with minimal economic value, but should be considered as profitable alternatives leading to valuable products of commerce (No et al., 1992). Similar research studies by Lee (1989) demonstrated that the astaxanthin-rich shell from crawfish waste is a valuable natural resource for commercially feasible pigment which is marketed as a fish food additive in aquaculture, especially for Salmon. Apart from the recoverable pigment, it has been shown that crawfish shell waste possesses a significant and renewable major resource for the biopolymer chitin (23.5% on a dry basis compared to 14-27% and 13-15% of the dry weight of shrimp and crab processing waste, respectively) and chitosan (No and Meyers, 1989,1992). Therefore, the applications of crawfish shell wastes as a source of astaxanthin, chitin and chitosan represent a total byproduct utilization concept with realistic implications in other crustacean waste recovery industries (No and Meyers, 1989). Further significance can be seen in the utilization of astaxanthin pigment, chitin, and protein from crawfish shell as mentioned earlier in a variety of fields with different applications. However, this thesis study will focus on the isolation of chitosan with crawfish shell as a source. 2
Crawfish shell as well as crustacean shell waste, mainly consist of protein (30-40%), calcium carbonate (30-50%), and chitin (20-30%) on a dry basis (Johnson and Peniston, 1982). These proportions vary with species and seasons (Green and Kramer, 1984). Chitin represents one third of the shell composition, and is highly hydrophobic and insoluble in water and most organic solvents. Chitosan, the deacetylated product of chitin, is soluble in very dilute acids such as acetic acid or formic acid. Traditional isolation of chitin from crustacean shell waste consists of three basic steps: demineralization (DM-calcium carbonate and calcium phosphate separation), deproteinization (DP-protein separation), and decolorization (DC-removal of pigments). These three steps are the standard procedure for chitin production (No, 1989). The subsequent conversion of chitin to chitosan (DA, deacetylation) is generally achieved by treatment with concentrated sodium hydroxide solution (40-50%) at 100ºC or higher to remove some or all of acetyl group from the chitin (No and Meyers, 1995). Earlier studies by No et al. (2000b); Cho et al. (1998); Wu and Bough (1978) have demonstrated that the physicochemical characteristics of chitosan affect its functional properties, which also differ due to crustacean species and preparation methods. Several procedures have been developed and proposed by many researchers over the years for preparation of chitosan from different crustacean shell wastes. Some of these formed the basis of chemical processes for industrial production of chitosan. Few attempts have been made to compare functional properties of chitosans prepared from various processes with those of commercially available chitin and chitosan products. Rout (2001) evaluated the effects of reversing the first two steps (deproteinization or demineralization) or reducing the number of steps (deproteinization or decoloration or either both) on fat and water binding capacities of chitin and chitosan, and reported a high fat binding capacity with crab and crawfish chitosan when the processing step 3
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: CHAPTER 1 INTRODUCTION Chitosan is
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 and 52: The shell was almost impossible to
Page 53 and 54: ut the values were slightly higher
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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