Orange juice ultrafiltration: Characterisation of deposit layers and membrane surfaces after fouling and cleaning

Nurul Hainiza Abd-Razak, Y. M.John Chew, Michael R. Bird

Research output: Contribution to journalArticlepeer-review

Abstract

The influence of feed condition and membrane cleaning during the ultrafiltration (UF) of orange juice for phytosterol separation was investigated. UF was performed using regenerated cellulose acetate (RCA) membranes at different molecular weight cut-off (MWCO) values with a 336 cm2 membrane area and a range of temperatures (10-40 °C) and different feed volumes (3-9 L). Fluid dynamic gauging (FDG) was applied to assess the fouling and cleaning behaviours of RCA membranes fouled by orange juice and cleaned using P3-Ultrasil 11 over two complete cycles. During the FDG testing, fouling layers were removed by fluid shear stress caused by suction flow. The cleanability was characterised by using ImageJ software analysis. A Liebermann-Buchard-based method was used to quantify the phytosterol content. The results show that RCA 10 kDa filters exhibited the best separation of phytosterols from protein in orange juice at 20 °C using 3 L feed with a selectivity factor of 17. Membranes that were fouled after two cycles showed higher surface coverage compared to one fouling cycle. The surface coverage decreased with increasing fluid shear stress from 0 to 3.9 Pa. FDG achieved 80-95% removal at 3.9 Pa for all RCA membranes. Chemical cleaning using P3-Ultrasil 11 altered both the membrane surface hydrophobicity and roughness. These results show that the fouling layer on RCA membranes can be removed by fluid shear stress without affecting the membrane surface modification caused by chemical cleaning.

Original languageEnglish
JournalInternational Journal of Food Engineering
Early online date27 Sep 2021
DOIs
Publication statusE-pub ahead of print - 27 Sep 2021

Keywords

  • fouling
  • orange juice
  • shear stress
  • ultrafiltration

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Engineering (miscellaneous)

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