Sucrose maltodextrin films

Glass-Transition Temperature and Self-Detaching of Maltodextrin Films Effect of Molecular Weight and Sucrose Addition... 

Detachment conditions of mixtures of maltodextrin MOR-REX1910 and sucrose dried film from the glass plate surface. 

Spray Drying. Spray-dry encapsulation processes (Fig. 7) consist of spraying an intimate mixture of core and shell material into a heated chamber where rapid desolvation occurs to thereby produce microcapsules (24,25). The first step in such processes is to form a concentrated solution of the carrier or shell material in the solvent from which spray drying is to be done. Any water- or solvent-soluble film-forming shell material can, in principle, be used. Water-soluble polymers such as gum arable, modified starch, and hydrolyzed gelatin are used most often. Solutions of these shell materials at 50 wt % soHds have sufficiently low viscosities that they stiU can be atomized without difficulty. It is not unusual to blend gum arable and modified starch with maltodextrins, sucrose, or sorbitol. 

The effect of mixtures on the detachment conditions was also evaluated by dr)dng pastes made by a mixture of maltodextrin MOR-REX 1910 and sucrose, with a total solid content of 61.5%, but with increasing amount of sucrose (5, 10, and 15% sucrose, dry weight basis (dwb)). Results in Figure 21.3 indicate that for a defined drying temperature, the moisture content at the moment of self-detachment of the dried film decreased with the increase in sucrose addition. Thus the addition of sucrose made the detachment of dried films of maltodextrin from an inert solid surface during the drying process more difficult. The larger the amount of sucrose added. 

In Figure 21.5, the self-detachment conditions for aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose at 5, 10, and 15% (dwb) are compared with the glass-transition curves calculated using the expanded Gordon-Taylor model (Roos, 1993). The self-detachment of the dried films of aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose followed the same pattern of decreasing moisture content of the material with an increase in temperature as observed with the glass-transition data. This process occurred in a temperature range of 20°C below Tg, for 5,10, and 15% sucrose concentrations, as was observed by Collares et al. (2004) for maltodextrin MOR-REX 1910 without the addition of sucrose. 

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