ISSN:
0006-3525
Keywords:
κ-carrageenan
;
κ-carrageenan-locust bean gum mixtures
;
small deformation oscillation measurements
;
differential scanning calorimetry
;
locust bean gum
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The solution properties of κ-carrageenan and κ-carrageenan/locust bean gum mixtures have been studied by small deformation oscillation measurements and differential scanning calorimetry (DSC) in the presence of sodium chloride and sodium iodide. Both salts induced the κ-carrageenan to undergo a coil-helix conformational change as noted by an increase in the storage and loss moduli (G′, G′) and by an exothermic peak in the DSC cooling curves. The enthalpy ΔHc-h and temperature of the conformational transition Tc-h were higher in Nal compared to NaCl and Tc-h increased with increasing the concentration of both electrolytes. Gelation was not observed for carrageenan or carrageenan/locust bean gum mixtures in the presence of up to 200 mM Nal. Although carrageenan alone did not gel in the presence of 100 mM NaCl, a weak gel was obtained for a mixture containing 0.9%/0.1% carrageenan/locust bean gum. Furthermore, the mixture showed hysteresis in both the rheological and DSC cooling and heating curves. A strong gel was produced for carrageenan alone in the presence of 200 mM NaCl and the gel strength increased on adding a small proportion of locust bean gum (0.9%/0.1%). © 1997 John Wiley & Sons, Inc. Biopoly 41: 657-671, 1997
Additional Material:
16 Ill.
Type of Medium:
Electronic Resource
