Cross‐flow Microfiltration with Gas Backwash of Apple Juice

Abstract

ABSTRACT Cross‐flow microfiltration (MF) was applied for clarification of commercially pressed depectinized apple juices and pectin containing artificial apple juice suspensions under continuous low pressure inlet conditions (35 kPa ‐ 209 kPa). Periodic gas backwash (air or N 2 ) removed solids from exteriors of 0.2 μm cut‐off hollow fiber polypropylene membranes. Flux and nephelos turbidity units (NTU) of filtrates for both commercial juices and artificial juices were evaluated. Commercial juices after vacuum filtration and MF had 100–110 L/m 2 /hr flux during 2 hr operation. Low pectin (1%) artificial juices had ∼70 L/m 2 /hr flux during 1.5 hr. NTUs of filtrates from all treatments were <0.69. All filtrates were commercially sterile.