ABSTRACT
Introduction ........................................................................................................ 663
Materials and Methods ..................................................................................... 664
Preparation of Model Systems................................................................. 664
Methods ....................................................................................................... 664
Results and Discussion ..................................................................................... 665
Acknowledgments ............................................................................................. 668
References ........................................................................................................... 668
It is well known that carbohydrates, particularly disaccharides, can provide
significant protection to labile biomolecules during dehydration and their
later storage and they are widely employed in biological, pharmaceutical,
and food science (Leslie et al., 1995; Crowe et al., 1998). The action of the
protective effect can be ascribed to both kinetic and specific effects. At the
kinetic level, dehydroprotectants promote the formation of amorphous,
glassy systems, inhibit crystallization, and influence the kinetics of
deteriorative reactions upon storage. At the specific interaction level,
protectants are believed to interact (mainly by hydrogen bonding) with
biological structures and stabilize them, although by different mechanisms
(Carpenter and Crowe, 1988; Crowe et al., 1996). Salts modify important
properties of sugar systems, affecting their efficiency as protein stabilization
agents (Carpenter et al., 1987; Mazzobre and Buera, 1999; Mazzobre et al.,
2001) and their effect is of special interest because of their universal presence
in foods and in biological systems. Sugar-metal complexes can be formed in
solution (Angyal, 1973; Morel-Desrosier et al., 1991) and it has been reported
that salts affect the kinetics of sugar crystallization, Maillard reaction, and
sugar hydrolysis. However, the several possible effects of salts on the kinetics
of those important interrelated phenomena has not been analyzed
simultaneously. The purpose of the present work was to analyze the effect
of MgCl
on chemical and physical properties of two nonreducing
disaccharides. Glass-transition temperatures and the kinetics of sugar
hydrolysis, Maillard reaction, and crystallization were compared for sucrose
and trehalose.
