Strawberry fluidized bed drying. Antiadhesion pretreatments and their effect on bioactive compounds

• Pretreatment with CaCl 2 reduces adhesion in strawberry cubes. • Fluidized bed drying of strawberry cubes reduces drying time by 43 %. • Fluidized bed drying negatively influences the anthocyanin content in strawberries. Fluidized bed drying is used little in fruits due to the high density of particles and the tendency toward adhesion, which reduces the ability to suspend them in a stream of hot air. Technologies, such as inert auxiliary materials and mechanical systems, have been previously evaluated to improve fluidization. This work assessed solutions of CaCl 2 and ascorbic acid applied as a pretreatment to reduce adhesion. The color and drying kinetics were determined. The degree of interparticle adhesion was determined using a texturometer, and the kinetics of phenolic compounds and anthocyanins were determined using the Folin-Ciocalteu colorimetric and pH-differential methods, respectively. The results showed a significant reduction in adhesion in samples pretreated with CaCl 2 . A 43 % reduction in drying time using FBD compared to tray drying was found. The final anthocyanin content was between 0.06 and 0.2 mg C3G /g dn , while the concentration of phenolic compounds was between 22.14 and 52.16 mg GAE/g dm .