No description available.

Due to increasing use of whey proteins in functional foods and pharmaceutical products there is a need to develop processes to selectively separate and concentrate individual whey proteins. Existing methods for large-scale separation of whey proteins have included reverse osmosis, ultrafiltration, microfiltration and ion exchange. This study looked specifically at the use of synthetic microporous membranes, with functional groups covalently attached, to selectively separate β-lactoglobulm bovine serum albumin (BSA), α-lactalbumin, lactoferrin, lactoperoxidase and finally caseinomacropeptides from rennet whey. Initially strong cation exchangers and anion exchangers were considered, later this was expanded to include weak anion exchangers.

The aim of this study was to gain a better understanding of the relationship between calcium status and physicochemical properties, and of milk stability when subjected to various processing treatments. Variations in milk due to breed, stage of lactation. season and diet (spring flush) were studied. When comparing Friesian and Jersey cows milk, Jersey cows milk contained more protein, fat and calcium but less ionic calcium. Correlations exist between the protein and calcium concentration, which affects other characteristics such as stability and clotting properties. Spring flush did not have a statistically significant effect on changes in the data obtained; however, the data did differ statistically significantly from week to week. There was a lot of variability in the samples during the summer months, which could be attributed to heat stress because of particularly hot weather during the summer of 2006.

No description available.

No description available.

The use of microfiltration as an alternative to pasteurisation to reduce the microbial load of raw skimmed milk is a well established technology. However, its application in reducing bacteria from highly viscous dairy based solutions has not due to issues of low flux and high fouling tendency. This study involves the application of microfiltration to remove spores from high solids content Milk Protein Isolate (MPI) solutions. MPI feeds were inoculated with Bacillus mycoides spores a safer alternative to Bacillus cereus, a psychrotrophic spore forming bacteria found in dairy feeds. Suitable protocols for MPI resolubilisation, Bacillus mycoides cell and spore preparations were established and the membranes, MPI and spores were fully characterised by scanning electron microscopy (SEM), particle size distribution, rheology and pure water flux (PWF) measurements. Feed and permeate samples collected during experiments were analysed for solids content by oven drying, protein content using the Bradford assay and spore content using PetrifilmTM Aerobic count plates. To try and determine an optimum protocol for MPI filtration, a variety of filtration rig set-ups, modules and membranes were tested. Experiments were carried out at different MPI concentrations (4 – 16 wt%), cross flow velocities (CFV’s) (0.7 – 2.0 m s-1) and transmembrane pressures (TMP’s ) (1 and 2 bar). The filtration of 15 wt% MPI proved challenging. The best set of results were obtained using the 12.0 μm membrane at 1.4 m s-1, producing a 27 LMH flux, 96.5% protein transmission and a 2.1 log spore reduction. These results indicate that large pore ceramic microfiltration may be a suitable technology to replace or augment pasteurisation for high solids content dairy feeds. The effect of backwashing using different durations and frequencies was investigated. Backwashing parameters of 10 seconds every 5 minutes at 1 bar were found to be the most effective. The optimum cleaning regime found for MPI fouled ceramic membranes involved a long rinsing backflush at 1 bar, acid and alkali steps without backwashing, which produced a 99.6% flux recovery.

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Der Bericht informiert Milchproduzenten, Berater und Planer über den Energiebedarf konventioneller Melkanlagen sowie Anlagen zur Kühlung von Milch. Enthalten sind sowohl die Ergebnisse von Praxismessungen mit vielen Details als auch Modellkalkulationen. Im Ergebnis werden Empfehlungen für eine Optimierung der Energieeffizienz abgeleitet.

La hausse progressive des quotas laitiers jusqu’à leur suppression prévue en 2015 conduit à la perte, pour les producteurs laitiers, d’un outil de gestion de la concurrence entre producteurs et entre territoires. Ces évolutions politiques et la transformation consécutive des marchés peuvent remettre en cause la pérennité de la production laitière, en particulier dans certaines zones de montagne. L’objectif de ce travail est de proposer un cadre conceptuel d’analyse du changement de forme de concurrence dans le secteur laitier et de le valider empiriquement avec le cas des montagnes françaises.L’approche institutionnelle retenue permet de construire des outils analytiques et d’explorer le rôle de l’action collective, à différentes échelles, dans la capacité de réponse des territoires de montagne. Dans ce cadre, les régimes de concurrence désignent l’arrangement institutionnel des dispositifs de coordination, recouvrant à la fois les instruments publics et les structures de coordinations (professions, interprofessions et standards) ainsi que les dispositifs et acteurs de l’innovation. Ces institutions et, donc, ces régimes de concurrence se déploient à différentes échellesgéographiques. La France laitière étant diversifiée, ces arrangements institutionnels varient d’un territoire à l’autre, selon les modèles de production et d’entreprise, l’orientation des marchés, la nature des structures professionnelles et interprofessionnelles et, d’une manière générale, selon les relations entre acteurs des filières. Les systèmes régionaux de production se caractérisent donc par différents régimes de concurrence. L’extension de la notion de bien commun et l’adaptation du concept de régime de droits de propriété à la capacité à exercer un contrôle sur les prix (propriété intangible) permettent de déterminer la capacité des producteurs à accéder aux deux biens communs à l’origine de la différenciation d’un régime de concurrence : la structure de gouvernance (à l’origine d’une capacité d’innovation) d’une part et la réputation collective (à l’origine d’une prime de marché) d’autre part.La différenciation régionale des régimes de concurrence nous conduit à proposer une hypothèse empirique sur le devenir des bassins de production de montagne : leur viabilité pourrait reposer sur l’activation de ressources collectives sectorielles et territoriales spécifiques, permettant une différenciation des formes et des espaces de concurrence. Dans les systèmes déjà partiellement différenciés (Savoie(s) et Jura), les innovations pourraient être incrémentales alors qu’elles risquent de devoir être radicales dans les autres zones (Massif Central, Pyrénées, reste des Alpes).Une analyse des stratégies d’acteurs, réalisée à plusieurs échelles géographiques, et reposant sur la combinaison d’études de cas et de méthodes économétriques, apporte une vision nouvelle de la diversité des mécanismes territoriaux de la restructuration laitière.Quarante-trois territoires de montagne, regroupés en quatre principaux ensembles – montagne à AOC forte, montagne à potentiel AOC, montagne générique dense, montagne générique peu dense – sont distingués et cartographiés. Ces différences territoriales montrent que le cadre juridique proposé par l’acteur public dans le cadre du Paquet lait n’est pas suffisant pour assurer la stabilité des marchés après la suppression des quotas, en particulier dans les zones difficiles sans régime de concurrence différencié. Ce cadre juridique repose en effet sur une incitation (i) au développement de relations contractuelles entre opérateurs de la filière et (ii) à la constitution d’organisations de producteurs. Il ressort qu’il sera nécessaire d’accompagner en parallèle les producteurs dans la construction d’une offre de lait et de services territorialisés, offre qui doit être adaptée à la demande des industries et des pouvoirs publics (collectivités locales, État, Europe). / With the gradual increase of the milk quotas until their abolition planed in 2015, dairy farmers loose a mean to control competition among producers and between areas. This political change and the consequential markets’ transformation question the future of mountain dairy farming. The objective of this work is to propose a conceptual framework to analyse the change of competition regime in the dairy industry and to validate it empirically with the case of the French mountainous production areas.The scientific approach corresponds to an inclusion in the field of institutional economics. It enables the building of analytical tools and the exploration of the role of collective action, at various scales, in the response capacity of mountainous production areas. In this framework, competition regimes correspond to the institutional arrangement of coordination instruments that covers political instruments and coordination structures (professions, joint-trade organisations and standards) as well as innovation networks. These institutions and thus competition regimes spread over various scales.The French dairy industry being diversified these institutional arrangements vary across regions, based on the enterprises and production models, on markets’ orientation, on the nature of professional and interprofessionnal organisations, and finally on the general relationships among supply chains’ operators. Regional production systems are thus characterised by various competition regimes. The field of common pool resources has been extended and the concept of property rights regimes has been adapted to the ability to control prices (intangible property). Thus the dairy farmers’ capacity to access to the two common pool resources at the origin of the differentiation of a competition regimes, namely governance structures (at the basis of an innovation capacity) and collective reputation (at the source of a market premium), can be understood.The regional differentiation of competition regimes suggests the following empirical hypothesis: the viability of mountain production areas could rest on the activation of various territorial and sectional resources that enables a differentiation of the competition regimes. Innovations’ strategies could be incremental in areas with an already partially differentiated regional production system (Jura and Savoie) whereas it may have to be radical in other areas.The analysis of economic players’ strategies at various scales, based on an articulation of three case studies and of an econometric analysis, contributes to the understanding of the diverse territorial mechanisms of the dairy restructuring.Forty-three mountainous areas, gathered in four subsets – mountainous areas with strong PDO cheese, areas with a potential for PDO cheese, areas targeting generic markets either with high farm density or with low farm density –, have been distinguished and mapped. These regional differences shows that the new legal framework laid down by the public actor within the context of the Milk Package maynot be sufficient to enable market stability especially in some mountainous areas, once the quotas have been abolished. This legal framework rests indeed on an incentive (i) to establish contracts among supply chains’ operators and (ii) to constitute farmers’ organisations. It comes out that it may be necessary to support at the same time the dairy producers’ abilities to build a supply of milk and territorialised services ; a supply that has to match the demand of the industry as well as the one of the public-players (local administrations, state, Europe).