کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4909210 | 1427105 | 2017 | 9 صفحه PDF | دانلود رایگان |
- Crystallization, structural relaxations and strength studied in lactose/WPI mixtures.
- Fractional water sorption found in lactose/WPI systems based on DDI sorption.
- WLF with the material-special constants successfully modeled Ï and Tα-Tg.
- S concept related to water induced crystallization and measured compositional effects.
Water sorption-induced crystallization, α-relaxations and relaxation times of freeze-dried lactose/whey protein isolate (WPI) systems were studied using dynamic dewpoint isotherms (DDI) method and dielectric analysis (DEA), respectively. The fractional water sorption behavior of lactose/WPI mixtures shown at aw â¤Â 0.44 and the critical aw for water sorption-related crystallization (aw(cr)) of lactose were strongly affected by protein content based on DDI data. DEA results showed that the α-relaxation temperatures of amorphous lactose at various relaxation times were affected by the presence of water and WPI. The α-relaxation-derived strength parameter (S) of amorphous lactose decreased with aw up to 0.44 aw but the presence of WPI increased S. The linear relationship for aw(cr) and S for lactose/WPI mixtures was also established with R2 > 0.98. Therefore, DDI offers another structural investigation of water sorption-related crystallization as governed by aw(cr), and S may be used to describe real time effects of structural relaxations in noncrystalline multicomponent solids.
Journal: Journal of Food Engineering - Volume 196, March 2017, Pages 150-158