Exploring centrifugal-percolation as an innovative external force in block freeze concentration technology applied to peppermint infusion

This study investigates the use of centrifugal-percolation block freeze concentration (CP-BFC) at three cycles to obtain concentrate fractions from peppermint (Mentha piperita L.) infusion. The process parameters, physicochemical properties, bioactive compounds (total polyphenol (TPC) and flavonoid (TFC) content, and HPLC analyses), and antioxidant capacity of the concentrated fractions were evaluated. After three CP-BFC cycles, the process parameters were close to 95 % and 66 % for efficiency of separation and solute yield, respectively. Moreover, the results demonstrate that the percolation system can be incorporated in the centrifugation step, and thus, both separation steps carry out a successful extraction of concentrate solutes (11.7 % w/w and 13.5°Brix) from the ice fraction, with TPC and TFC values of 13.21 mg gallic acid equivalents/mL and 15.93 mg catequin equivalents/mL, respectively. Vanillic acid, rutin, and kampferol presented the highest concentration among all the phenolic compounds. While, antioxidant capacity changes ranged until 47 and 206 μmol trolox equivalents/mL, for DPPH and FRAP assays, respectively. These findings (high extraction and high concentration of solutes, bioactive compounds and antioxidant capacity) highlight the potential by adding a percolation system in the centrifugation process as a novel symbiotic strategy for high-quality liquid food concentration, effectively balancing process parameters and product quality, with potential for semi-industrial scale concentration of solutes and bioactive compounds. Therefore, centrifugal-percolation is an alternative external force to couple with BFC technology due to the double separation, since the process increased and preserved bioactive compounds to produce concentrated solutions with endless possibilities for multifarious food, medical, and pharmaceutical applications.