RECRYSTALLIZATION OF AMYLOPECTIN IN CONCENTRATED STARCH GELS

The relation between the recrystallization of amylopectin and the incr ease in stiffness of starch gels during storage was studied by various techniques. From transmission electron microscopy it was concluded th at the size of the crystalline domains in retrograded 30% w/w potato s tarch gels was about 5 nm, much smaller than those present in native s tarch. The super-helical structure formed by the crystalline domains i n native starch granules was not seen. It may thus be concluded that i n retrograded starch gels the long range ordering is not regained duri ng retrogradation. The relation between the degree of recrystallizatio n, as determined with differential scanning calorimetry (DSC), and the increase in stiffness, as measured in compression, was found to be cl osely related. Two mechanisms will be discussed which may explain thes e observations. Copyright (C) 1996 Elsevier Science Ltd