Microencapsulated β-carotene preparation using different drying treatments.

β-Carotene is one of the most abundant natural pigments in foods; however, usage of β-carotene is limited because of its instability. Microencapsulation techniques are usually applied to protect microencapsulated β-carotene from oxidization. In this study, β-carotene was microencapsulated using different drying processes: spray-drying, spray freeze-drying, coating, and spray granulation. The properties of morphology, particle size, water content, thermal characteristic, and chemical stability have been explored and compared. Scanning electron microscopy measurements showed that the coated powder had a dense surface surrounded by starch and suggested that the coating process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders. The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures. The coated powder had the highest mass fraction of β-carotene, which indicated that the coating process was superior to the three other drying processes.