Effect of trehalose dehydration on crystal morphology and food caking during post-treatment

Morphological changes of trehalose crystals during drying and reprocessing lead to a series of post-processing problems, which result in a significant investment in production costs. In this work, the mechanism of drying temperature on the morphology and caking behavior of trehalose was investigated. When the drying temperature was too high (≥393.15 K), a large number of pores, cracks and burrs appeared on the surface of crystals. These lead to crystal fragmentation during agitated drying process. The dehydration kinetics showed that the rearrangement of the new structure after dehydration and the change of the dehydration mechanism were the reasons for the morphological changes of trehalose crystals. Caking experiments showed that the dried product exhibited higher hygroscopicity and tendency to caking. Compared with trehalose dihydrate, the product flowability decreased by 30.0 %, critical caking period decreased by 82.1 %, and caking strength increased by 13 times after high-temperature drying (413.15 K).