This article provides an overview of recent developments and the published literature in membrane technology with regard to fruit juice processing and considers the impact of such technology on product quality. In the fruit juice industry, membrane technology is used mainly to clarify the juice by means of ultrafiltration and microfiltration and to concentrate it by means of nanofiltration and reverse osmosis. We look at enzyme immobilization techniques to improve filtration performance and operation methods to quantify fouling. Membrane fouling is a critical issue and inhibits the broader application of membranes in the fruit production industry. Pectin and its derivatives form a gel-like structure over the membrane surface, thereby reducing the permeate flux. In order to degrade pectin, the raw juice is usually subjected to an enzymatic treatment with pectinase, which hydrolyses pectin and causes its protein complexes to flocculate. The resulting juice has reduced viscosity and a much lower pectin content, which is advantageous in the subsequent filtration processes.

Fruit Juice Processing and Membrane Technology Application

Evaluation of cleaning efficiency of ultrafiltration membranes fouled by BSA using FTIR–ATR as a tool

Invited review: Microfiltration-derived casein and whey proteins from milk.

Separation of polyphenols and proteins from flaxseed hull extracts by coagulation and ultrafiltration

Modeling organic fouling of reverse osmosis membrane: From adsorption to fouling layer formation

Skim milk microfiltration (MF) is a well established dairy processing operation to remove whey proteins. This is classically completed using ceramic membranes under the uniform transmembrane pressure (UTMP) concept. However, there is a growing interest in the use of spiral wound polymeric membranes for this purpose due to their lower capital cost. In this work we show that polymeric and ceramic membranes provide comparable performance during skim milk MF when operated at comparable levels of transmembrane pressure (TMP), shear stress and temperature. Operation is strongly affected by both TMP and temperature but is less affected by crossflow velocity under the conditions utilised here. However, while polymeric membranes offer similar performance, it will be operationally difficult to retain the necessarily low TMP at the industrial scale, due to the lack of a comparable UTMP configuration.

Kensuke Karasu

Papers

A comparison between ceramic and polymeric membrane systems for casein concentrate manufacture

A combined model for the prediction of the permeation flux during the cross-flow ultrafiltration of a whey suspension

A model for cross-flow ultrafiltration of dairy whey based on the rheology of the compressible cake

A simple combination model for filtrate flux in cross-flow ultrafiltration of protein suspension