Centrifugal Filter-Assisted Block Freeze Crystallization Applied to Blueberry Juice

Abstract

The impact of centrifugal-filter assisted block freeze crystallization (CFBFC) on the physicochemical parameters, total phenolic content (TPC), total anthocyanin content (TAC), and total flavonoid content (TFC), antioxidant activity (AA) and process parameters applied to blueberry juice was studied. Additionally, CFBFC was contrasted with gravitational BFC (GBFC) and centrifugal BFC (CBFC) techniques. For CFBFC process, the solutes values were ≈35.9 °Brix (fresh juice ≈13.8 °Brix), with a very dark red/purple color. Moreover, the bioactive components values presented a significant increase of 2.1, 2.0, 1.8, and 3.1 times compared to the initial TPC, TAC, TFC, and AA values, respectively, and these values were higher than GBFC and CBFC techniques. For efficiency, percentage of concentrate, and solute yield, CFBFC showed values close to 86%, 81%, and 0.9 (kg/kg), respectively, which were higher values than GBFC (48%, 38%, and 0.5 (kg/kg)) and CBFC (79%, 68%, and 0.7 (kg/kg)). Therefore, this research offers new benefits with the addition of the filter in the centrifugal BFC, and thus, CFBFC offers an advantage due to the better separation than GBFC and CBFC, since the filter can be designated as a second separation stage, and only one cycle is necessary to obtain high quality properties in the final solution.