Effects of pretreatments on drying of Turkey berry (Solanum torvum) in fluidized bed dryer

Abstract

The influence of pretreatment methods like physical, chemical, combined physical, and hybrid treatments on the Turkey berry (Solanum torvum) fruits to enhance the water diffusion during drying was assessed due to removing a waxy layer on the peel. Pretreated and untreated samples were dried at 70 ⁰C and 4 m/s of air flow in a fluidized bed dryer. Fruits pretreated with combined abrasion and blanching have the lowest drying time and good vitamin C content retention of 36%. The highest drying rate of 0.396 kg water/kgdb min−1, maximum effective moisture diffusivity of 6.002 x 10-10 m2/s, and volumetric shrinkage ratio of 0.68 were obtained for fruits that undergone combined physical pretreatment along with drying. The maximum change in color ΔE = 14.75 and Chroma ΔC = - 10.53 were obtained for the untreated samples.

Keywords

• color
• effective moisture diffusivity
• pretreatment
• shrinkage
• turkey berry
• vitamin c