Impact of powder particle structure on the oxidation stability and color of encapsulated crystalline and emulsified carotenoids in carrot concentrate powders

The impact of the powder particle structure of spray dried and freeze dried carotenoid rich carrot concentrate powders on their oxidation stability and color was investigated. Depending on particle morphology (size distribution, porosity) and type of concentrate (crystalline or emulsified carotenoids), the encapsulation efficiency ranged from 43 to 88%, which led to marked differences in carotenoid stability during subsequent storage. For spray dried powders, the surface to volume ratio was recognized as crucial impact factor determining the encapsulation efficiency and carotenoid stability during storage. Spray dried powders with a low surface to volume ratio showed high carotenoid retention (76–77%) during storage (35 °C, 91 days), while the porous structure of freeze dried powders led to a rapid carotenoid degradation (69–93%) under the same storage conditions.