Freeze concentration of apple juice followed by centrifugation of ice packed bed

Abstract

Based on the porous morphological characteristics of the packed ice bed produced by suspension freeze concentration (FC), this study describes the introduction of a full-bed centrifugal filtration step to separate concentrated apple juice from the ice bed. After FC and centrifugal filtration, the recovery yield of soluble solids in the concentrated juice was 93.6%, with the other 6.4% solute lost due to the separation process. The permeability and permeability coefficient of the ice cake in the centrifugal filtration mathematical model were 4 × 10 −8 m 2 and 0.16 m s −1 , respectively. The specific resistance of the ice cake was 4.10 × 10 4 m kg −1 , which was at least one order of magnitude lower than that obtained from block FC. We believe that this strategy offers a viable alternative to the conventional wash column for the separation and purification of ice crystals and concentrate. • A process of freeze concentration of apple Juice followed by full-bed centrifugation of packed ice bed was presented. • The rotating speed of the centrifugal filter is 3000 rpm with a centrifuging factor of 503. • The recovery yield of soluble solids is 93.6% when the juice concentration achieved 40.3°Bx. • The permeability and permeability coefficient of the ice bed were 4 × 10 −8 m 2 and 0.16 m s −1 , respectively. • The specific resistance of the ice cake was 4.10 × 10 4 m kg −1 , less than one tenth of that of the ice block produced by block freeze concentration.