Optimization and Modeling of Apple Juice Cross‐flow Microfiltration with a Ceramic Membrane

Abstract

The performance of a 0.2 km ceramic membrane for clarification of depectinized apple juice was studied. The results showed that the flux was higher at high feed velocities (14.6 m/set) and high temperatures (5o"C), and the transmembrane pressure was a positive factor only at high temperatures. The juice flux at optimal conditions was between 4&J-500'kg/hr.m*. Filtration of juice with pectin resulted in flux decreases of 40-50% compared to deoectinized juice. Periodic backflushing during processing' at optimal conditions, i.e., high temperature, high feed velocity and low pressure, did not significantly increase the juice flux.

Clarification and Stability Enhancement of Pear Juice using Loose Nanofiltrationb

“…Permeate flux of PJS and PJWS was found to be approximately 2 times lower than the flux rate recorded for sucrose solution and approximately 3 times lower than water flux recorded at the same temperature (50°C). A similar trend was reported previously by Padilla-Zakour and McLellan [3]. These results indicated that drastic reduction in permeation rate was mostly due to high viscosity in the PCPJS feed, caused by high total soluble solids, which may have partially contributed to high osmotic pressure during the loose NF process of PCPJS (Figure 4).…”

“…Most fruit juices have a soluble solids concentration in the range of 12-22°Brix, which are made up mainly of sugars [3] and to a small extent of organic acids. Permeate flow rates of sugar solutions provide an indication of the maximum attainable output of the filtered juice under ideal conditions i.e.…”

“…The membrane resistance (RM), total membrane resistance (RT) and irreversible fouling resistance (RF) were calculated using the following equations [3]: The samples were analysed for pH, ºBrix, colour, clarity, titratable acidity as described by Vivekanand et al [4,5] Sugars (sucrose, glucose, fructose, and sorbitol), organic acids (citric acid, malic acid and ascorbic acid) and phenolic compounds (arbutin, 5-hydroxy methyl furfural, chlorogenic acid, caffeic acid, p-coumaric acid and rutin) in pear juice samples were determined following the method of Vivekanand et al [5] A Brookfield LVT viscometer at 60 rpm with a UL adapter (Brookfield Engineering Laboratories Inc., Stoughton, MA, USA) was used to measure the viscosity of pear juice at 20°C.…”

Effect of pretreatment with gelatin and bentonite on permeate flux and fouling layer resistance during apple juice ultrafiltration

“…Therefore, an enzymatic treatment of the raw juice before ultrafiltration is usually carried out in order to degrade pectic substances and other polysaccharides, with enzymes such as pectinases and amylases. Pectinases hydrolyze pectin and cause pectin-protein complexes to flocculate, thus improve the flux behavior (Alvarez, Alvarez, Riera, & Coca, 1998;Padila-Zakour & McLellan, 1993). Alternatively, mechanical methods, such as backwashing and pulsating inlet flow techniques have also been reported to improve flux behavior (Ben Amar et al, 1990;Su, Liu, & Wiley, 1993).…”

Permeate flux and fouling resistance in ultrafiltration of depectinized apple juice using ceramic membranes

“…In order to control membrane fouling during juice clarification, several flux enhancement methods have been proposed such as periodic gas backwashing with air or N 2 (Su, Liu, & Wiley, 1993), permeate backwashing by pulsating entry flow (Ben Amar, Gupta, & Jaffrin, 1990;Padilla & McLellan, 1993), and enzymatic treatment before UF (Alvarez, Alvarez, Riera, & Coca, 1998).…”