Modelling the properties of liquid foods for use of process flowsheeting simulators: Application to milk concentration

In this paper, a modelling approach for liquid food products in a chemical process simulator is proposed from the flowsheeting methodology widely used for chemical processes. The focus is set on dairy concentration processes, in which milk is defined as a mixture of water and four dry matter components (fat, proteins, carbohydrates, minerals) modelled as “pseudo-components” in a conventional simulator which has been adapted to take into account the behaviour of the liquid food product considered. The significant properties of milk (heat capacity, boiling point elevation, thermal conductivity, density, viscosity, surface tension) are modelled with empirical models found in the literature and implemented in the simulator. In order to validate the approach, an industrial milk evaporation process and a pilot-scale evaporator are modelled and simulated. The results are compared with industrial and experimental results respectively, and show a good agreement with the industrial process. However improvements are needed in modelling the pilot scale evaporator. The proposed approach is generic enough to be extended to other liquid foods

A General Approach for Predicting the Filtration of Soft and Permeable Colloids: The Milk Example

Membrane filtration operations (ultra-, microfiltration) are now extensively used for concentrating or separating an ever-growing variety of colloidal dispersions. However, the phenomena that determine the efficiency of these operations are not yet fully understood. This is especially the case when dealing with colloids that are soft, deformable, and permeable. In this paper, we propose a methodology for building a model that is able to predict the performance (flux, concentration profiles) of the filtration of such objects in relation with the operating conditions. This is done by focusing on the case of milk filtration, all experiments being performed with dispersions of milk casein micelles, which are sort of ″natural″ colloidal microgels. Using this example, we develop the general idea that a filtration model can always be built for a given colloidal dispersion as long as this dispersion has been characterized in terms of osmotic pressure Π and hydraulic permeability k. For soft and permeable colloids, the major issue is that the permeability k cannot be assessed in a trivial way like in the case for hard-sphere colloids. To get around this difficulty, we follow two distinct approaches to actually measure k: a direct approach, involving osmotic stress experiments, and a reverse-calculation approach, that consists of estimating k through well-controlled filtration experiments. The resulting filtration model is then validated against experimental measurements obtained from combined milk filtration/SAXS experiments. We also give precise examples of how the model can be used, as well as a brief discussion on the possible universality of the approach presented here

Eco conception des procédés alimentaires

absen

Applications des opérations à membranes dans l'industrie laitière

Formation Archimex "Systèmes membranaires et technologies de filtration-purification" 9-11/10/2001 *INRA Laboratoire de Recherches de Technologie laitière Rennes (FRA) Diffusion du document : INRA Laboratoire de Recherches de Technologie laitière Rennes (FRA)National audienc

Research Activities in Process Engineering

Research Activities in Process Engineering. Journée Valoria WoFin Meetin

Ultrafiltration et microfiltration tangentielles. Principes de transferts

*INRA Laboratoire de Recherches de Technologie Laitière Rennes (FRA) Diffusion du document : INRA Laboratoire de Recherches de Technologie Laitière Rennes (FRA)National audienc

Integrated membrane operations in whey processing

This comprehensive reference work describes in an instructive manner the combination of different membrane operations such as enzyme membrane reactors (EMR's), microfiltration (MF), ultrafiltration (UF), reverse osmosis (RO), nanofiltration (NF) and osmotic distillation (OD) is studied in order to identify their synergistic effects on the optimization of processes in agro-food productions (fruit juices, wines, milk and vegetable beverages) and wastewater treatments within the process intensification strategy. The introduction to integrated membrane operations is followed by applications in the several industries of the food sector, such as valorization of food processing streams, biocatalytic membrane reactors, and membrane emulsification

An overview of membrane applications in the dairy industry

An overview of membrane applications in the dairy industr

Fractionnement par membranes de molécules d'origine agro-alimentaire

Fractionnement par membranes de molécules d'origine agro-alimentaire. XIIIème journées Cathala-Letort SFG