Factors impacting sorbitol polymorphism and polymorphic transitions during aging

During the manufacture of sugar-free confectionery and pharmaceutical products, sorbitol can dissolve and recrystallize into a variety of different polymorphic structures, which can have an impact on stability and physical properties. In order to maintain desired attributes, factors that impact sorbitol polymorphic structure during shelf life must be understood and controlled. To study crystallization of sorbitol under static conditions, three different moisture content sorbitol syrups (3, 4, and 5%) were prepared and crystallized at 15, 40, and 65 °C for one week to determine differences in final polymorphic structure and well as changes in polymorphic structure during aging. The effects of mannitol and maltitol on sorbitol crystal structure in these low moisture sorbitol syrups were also determined. High temperatures and moisture contents increased the stability of sorbitol and accelerated polymorphic transitions while mannitol and maltitol had the opposite effect.