physicochemical and functional properties of crawfish chitosan as ...

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treatment under severe conditions causes depolymerization and deacetylation. To obtain uniformity in reaction, it is recommended to use relatively high ratios of solid to alkali solution of 1:10 or 1:15-20 with proper agitation because a minimum ratio of 1:4 (w/v) of shell weight to KOH solution, had only a minor effect on the DP efficiency of shells (No and Meyers, 1995). Optimal conditions for deproteinization involve treatment of the crawfish shells with 3.5% (w/w) NaOH solution for 2 hr at 65ºC with constant stirring and a solid to solvent ratio of 1:10 (w/v) (No et al., 1989). During the deproteinization process, foam formation can occur, but the foam is not as brisk and intense as that produced during demineralization. Shahidi and Synowiecki (1991) suggested that optimal deproteinization can be achieved using dilute potassium hydroxide solution. Generally, if maximizing protein yield and quality is the objective, then protein extraction before demineralization is recommended (Johnson and Peniston, 1982) or the pH of the aqueous solution must be reduced to the isoelectric point of protein for precipitation (Green and Mattick, 1979). 2.3.2 Demineralization Demineralization is usually accomplished by extraction with dilute hydrochloric acid (up to 10%) at room temperature with agitation to dissolve calcium carbonate as calcium chloride. A wide variation of the demineralization process has been reported in the literature. The use of HCl acid at higher concentration and also 90% formic acid to achieve demineralization has been reported. Optimum demineralization is achieved by constant stirring of the dried ground crawfish shell with 1N HCl for 30 min at ambient temperature and a solid to solvent ratio of 1:15 (w/v) (No et al., 1989). The ash content of the demineralized shell is an indicator of the effectiveness 20
of the demineralization process. Elimination of the demineralization resulted in products having 31-36% ash. During the demineralization process excessive undesirable foams are produced due to the CO2 generation ([CaCO3 + 2HCl → CaCl2 + CO2 () + H2O]). To control or reduce the foam, No et al.(1998) recommended the use of commercial antifoam comprising of 10% solution of active silicone polymer without an emulsifier. They also demonstrated that at 1.0ml of antifoam /L of 1N HCl, the performance of antifoam is more efficient during demineralization with smaller shell particle size (
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: Fortunately, the sequence of demine
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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