structure disappears. Considerable entanglement of amylopectin
chains will persist, and possibly even part of the large helix
structure will remain.- At higher temperature, swelling becomes extensive: see Figure
6.24c. Virtually allamylose leaves the granules. This actually is a
phase separation between amylose and amylopectin, as is
discussed in Section 6.5.2. Highly swollen though often irregularly
FIGURE6.25 Differential scanning calorimetry (DSC) as applied to potato starch–
water mixtures;%water (w/w) indicated near the curves. In DSC, the differential
amount of heat (or more precisely, enthalpy,H) needed to increase the temperature
ðdH/dTÞis registered as a function of temperatureðTÞ, and any melting (or similar
transition) causes a peak in the heat uptake. The peak area is proportional to the
melting enthalpy. In the figure, the specific heat capacity of the material has been
subtracted, providing horizontal base lines. (After results by J. W. Donovan.
Biopolymers18 (1979) 263.)