Effect of different sizes of ceramic membranes in the process of microfiltration on physicochemical parameters of chokeberry juice

The purpose of this study was to choose the right size of ceramic membranes in the process of microfiltration as regards the concentration of polyphenols measured by UPLC-PDA-MS/MS, antioxidant capacity analysed by ABTS and FRAP tests, viscosity, turbidity, precipitate, and parameters of colour evaluated in the CIE L*a*b* system of chokeberry juice. From all the tested sizes of ceramic membranes in the process of microfiltration, the best results were obtained for membranes with 0.8 mu m pores. This juice had a relatively high content of bioactive compounds, and the lowest values of turbidity, viscosity, and precipitation. The colour was an attractive and intense red, with no browning observed, before and after storage. The process of pasteurization caused a decrease in the content of bioactive compounds and antioxidant capacity and physical parameters. The storage time of 5months at 5 degrees C stabilized the content of polyphenolic compounds, improved clarity of chokeberry juice, stabilized turbidity, and limited deposit formation during storage.