Freeze concentration of apple juice followed by centrifugation of ice packed bed. (February 2021) - Qin, Frank G.F.
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. Highlights: 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.