Luc Fillaudeau

Recent and emerging applications of membrane processes in the food and dairy industry

Membrane processes have been major tools in food processing for more than 25 years. The food industry represents a significant part of the turnover of the membrane manufacturing industry world-wide. The main applications of membrane operations are in the dairy industry (whey protein concentration, milk protein standardization, etc.), followed by beverages (wine, beer, fruit juices, etc.) and egg products. Among the very numerous applications on an industrial scale, a few of the main separations which represent the latest advances in food processing, are reported. Clarification of fruit, vegetable and sugar juices by microfiltration or ultrafiltration allows the flow sheets to be simplified or the processes made cleaner and the final product quality improved. Enzymatic hydrolysis combined with selective ultrafiltration can produce beverages from vegetable proteins. In the beer industry, recovery of maturation and fermentation tank bottoms is already applied at industrial scale. During the last decade significant progress has been made with microfiltration membranes in rough beer clarification which is the most important challenge of this technology. In the wine industry the cascade cross-flow microfiltration (0.2 μ m pore diameter) – electrodialysis allows limpidity, microbiological and tartaric stability to be ensured. In the milk and dairy industry, bacteria removal and milk globular fat fractionation using cross-flow microfiltration for the production of drinking milk and cheese milk are reported. Cross-flow microfiltration (0.1 μ m) makes it possible to achieve the separation of skim milk micellar casein and soluble proteins. Both streams are given high added value in cheese making (retentate) through fractionation and isolation of soluble proteins ( β -lactoglobulin; α -lactalbumin) (permeate). At last, a large field of applications is emerging for the treatment of individual process streams at source for water and technical fluids re-use, and end-of-pipe treatment of wastewaters, while reducing sludge production and improving the final purified water quality.

Yeast cells, beer composition and mean pore diameter impacts on fouling and retention during cross-flow filtration of beer with ceramic membranes

Clarification of rough beer (RB) and pasteurisation of clarified beer (CB) by cross-flow microfiltration (CFMF) stand as potential applications of membranes in the food industry. This study is based on the comparison of the resistances to mass transfer obtained during the filtration of RB and CB. Empirical correlations made it possible to calculate the CB resistances for the same conditions of transmembrane pressure and cross-flow velocity as for the RB filtration runs. The 1.4 μm membrane led to much lower resistances than the other membranes because of the lower retention rates of the beer compounds such as proteins and polyphenols. In this case, the predominant fouling mechanism was due to the yeast cell layer which was very sensitive to cross-flow velocity. On the other hand, with the 0.1, 0.45 and 0.8 μm membranes, the retention or adsorption of the CB compounds, such as proteins and polyphenols was the predominant mechanism. The resistances obtained with the rough and CB were fairly similar. We assume that the presence of yeast cells lead to less compact proteins and polyphenols fouling.

Investigation of Mechanisms Governing Membrane Fouling and Protein Rejection in the Sterile Microfiltration of Beer with an Organic Membrane

Since the early 1980s, cold sterile crossflow microfiltration has been evaluated as a potential alternative to conventional thermal processes in the brewing industry (flash-or tunnel pasteurization). Up to now, industrial membrane development for beer microfiltration was limited both by severe membrane fouling and by protein and aroma compound retention. In the present work, fouling mechanisms and protein rejection have been investigated experimentally at laboratory scale for the microfiltration of a clarified (kieselguhr filtered) beer through a 0.2 mm polycarbonate membrane. Fouling mechanisms were analysed by using the constant pressure blocking filtration laws for which interactions arise between high molecular weight beer components and the membrane matrix resulting in pore constrictions and progressive blockage. Protein content in beer was measured using two dye-binding methods (Bradford and Lowry). It was found that permeate flux decay was governed by two successive fouling mechanisms: an internal pore fouling at the initial stages of filtration that conforms to the standard blocking model, followed by an external surface fouling conforming to the cake filtration model. The variation with time of membrane selectivity was characterized by a high initial protein transmission rate followed by a sharp decrease that occurs in a range of filtered volumes which is independent of the applied transmembrane pressure. For all experiments, protein retention level throughout the filtration was found to be closely related to the nature of fouling. It remains constant and low (

A Practical Method to Predict Steady-State Flux and Fouling in the Crossflow Microfiltration of Rough Beer with 1.40 μm Tubular Ceramic Membranes

In crossflow microfiltration (CFMF) of real food products (beer, wine, milk), fouling mechanisms and the local phenomenology associated with fouling are largely unknown and still unidentified. In this paper, an investigation has been carried out to determine the kinds of fouling and to look for a way to improve filtration performance. Different hydraulic resistances in series were measured to determine the significance of internal and external fouling in relation to operational parameters (crossflow velocity). The influence of pressure and velocity on the steady-state flux was investigated with a 1.40 μ m tubular ceramic membrane and the steady-state flux was described using an empirical equation. A working velocity range defined by a critical and an optimum velocity was determined, in which the filtration should be performed. This work gives new experimental results in rough beer CFMF and proposes an empirical equation which could be useful in the sizing of an industrial CFMF unit.

Brewing, winemaking and distilling: an overview of wastewater treatment and utilisation schemes.

Publisher Summary Brewers, winemakers, and ethanol producers are very concerned that the techniques they use are the best in terms of product quality, cost-effectiveness, and environmental impact. Consequently, energy consumption, water use, and wastewater generation constitute real economic opportunities for improvements in the existing process. This chapter highlights the emerging and existing constraints in relation to water and waste management in these industries and provides an overview of resource consumption. It describes the most common treatments and the associated constraints and advantages and discusses possible biological and technical alternatives to reduce water consumption and waste production. Several techniques can be considered as existing industrial practice, but livestock feed, discharge in soil, and biological (aerobic and anaerobic) treatments stand as the most widely used. The specificity of the brewing, winemaking, and distilling industries leads to different levels of development for each technique. The chapter presents their levels of development, advantages, and constraints. In the brewing and distilling industries, the most common treatment is livestock feed, discharge in soil, and biological treatment. In wine production, the choice of wastewater treatment techniques is based on the seasonal nature and dependent on winery production capacities.