CROSS-FLOW MICROFILTRATION WITH GAS BACKWASH OF APPLE JUICE

Cross-flow microfiltration (MF) was applied for clarification of comme rcially pressed depectinized apple juices and pectin containing artifi cial apple juice suspensions under continuous low pressure inlet condi tions (35 kPa - 209 kPa). Periodic gas backwash (air or N2) removed so lids from exteriors of 0.2 mum cut-off hollow fiber polypropylene memb ranes. Flux and nephelos turbidity units (NTU) of filtrates for both c ommercial juices and artificial juices were evaluated. Commercial juic es after vacuum filtration and MF had 100-110 L/m2/hr flux during 2 hr operation. Low pectin (1%) artificial juices had almost-equal-to 70 L /m2/hr flux during 1.5 hr. NTUs of filtrates from all treatments were <0.69. All filtrates were commercially sterile.