Melting behaviour of A- and B-type crystalline starch.
The melting behaviour of highly crystalline spherulites, of a short chain amylose DP-15 corresponding to both the A and B polymorphs of starch has been studied as a function of water content. At water contents greater than 40% w/w A-type spherulites melt at temperatures approximately 20 degrees C higher than B spherulites, whilst both crystal forms melt at lower temperatures in the presence of increasing amounts of water. Using the Flory-Huggins relationship for polymer crystal melting in the presence of a diluent, it is possible to predict a value for the ideal melting temperature of the dry crystals of 530 K.
Whittam
M A
MA
AFRC Institute of Food Research, Norwich, UK.
Noel
T R
TR
Ring
S G
SG
D000688:Amylose / Q000737:chemistry*; D003460:Crystallization; D013213:Starch / Q000737:chemistry*; D013696:Temperature
D013213:Starch; D000688:Amylose