Bacteriocin assisted food functional membrane for simultaneous exclusion and inactivation of Alicyclobacillus acidoterrestris in apple juice

Abstract

Alicyclobacillus acidoterrestris is a thermophilic and acidophilic bacilli species which causes a significant decay in quality of apple juice and it cannot be efficiently treated by conventional sterilization procedures in food processing. In order to efficiently remove and inactivate Alicyclobacillus acidoterrestris in apple juice, a food functional microfiltration membrane was fabricated by a multi-stage modification including polydopamine coating and nisin grafting. Attenuated total reflectance-fourier transform infrared spectrometer and scanning electron microscopy images confirmed the success of immobilizing polydopamine and nisin microspheres onto the polyvinylidene difluoride membrane surface. In comparison with pristine polyvinylidene difluoride membrane, the modified membrane showed promoted performance in terms of hydrophilicity, water flux and the rejection of Alicyclobacillus acidoterrestris. A simultaneous exclusion and inactivation of Alicyclobacillus acidoterrestris in apple juice was achieved by modified microfiltration membrane. The modified membrane also exhibited reliable stability under different membrane cleaning procedures. The present study provides an option for the development of tailored food functional membrane for specific applications in food processing.