Modelling of heat transfers and prediction of crystallization during cooling of chicken fat

Heat transfers that occurred during chicken fat dry fractionation process were characterized. The heat flux model developed led to follow the heat flux associated with crystallization (?r) during the cooling step. A crystallization kinetics was performed by measuring the solid content of the suspension of crystals at regular intervals by low-resolution pulsed nuclear magnetic resonnance. The variation of the total heat of crystallization calculated from the thermal model developed in this study was in good agreement with the crystallization kinetics. The results reported suggested that monitoring ?r during cooling could be useful for the prediction and control of crystallization kinetics and therefore the yield of fat dry fractionation process. (Résumé d'auteur

Rapport annuel 1996. Projet Cordet. Valorisation des produits de la pêche à Ouvéa

Le travail a porté sur le salage-séchage-fumage de poissons du lagon d'Ouvéa en Nouvelle Calédonie. Une unité pilote de salage-séchage-fuma ge a tout d'abord été mis en place et validée sur des filets de saumons. Les protocoles permettant de caractériser le degré de traitement des produits en terme de salage-séchage-fumage ont été mis au point. Des essais préliminaires ont ensuite été réalisés sur trois espèces du lagon : loches, bossus et becs de cane. Les premiers résultats obtenus sont encourageants et permettent de penser que ce procédé est une alternative prometteuse pour la valorisation des poissons d'Ouvéa

Linking objective and subjective modeling in engineering design through arc-elastic dominance

Engineering design in mechanics is a complex activity taking into account both objective modeling processes derived from physical analysis and designers’ subjective reasoning. This paper introduces arc-elastic dominance as a suitable concept for ranking design solutions according to a combination of objective and subjective models. Objective models lead to the aggregation of information derived from physics, economics or eco-environmental analysis into a performance indicator. Subjective models result in a confidence indicator for the solutions’ feasibility. Arc-elastic dominant design solutions achieve an optimal compromise between gain in performance and degradation in confidence. Due to the definition of arc-elasticity, this compromise value is expressive and easy for designers to interpret despite the difference in the nature of the objective and subjective models. From the investigation of arc-elasticity mathematical properties, a filtering algorithm of Pareto-efficient solutions is proposed and illustrated through a design knowledge modeling framework. This framework notably takes into account Harrington’s desirability functions and Derringer’s aggregation method. It is carried out through the re-design of a geothermal air conditioning system

Rapport final 1997. Projet CORDET : Valorisation des produits de la pêche à Ouvéa

La déshydratation-imprégnation par immersion a été appliquée à la valorisation de poissons du lagon d'Ouvéa. Le salage/séchage/fumage de ces produits a été optimisé et des essais de marinage ont été réalisés. Des produits fumés et marinés ont été préparés à Montpellier et présentés dans le cadre d'une mission en Nouvelle Calédonie. Pour leur fabrication, une petite chaîne pilote de salage/séchage/fumage et de marinage a été utilisée. Les personnes rencontrées au cours de cette mission ont été agréablement surprises par la qualité des produits transformés. Les résultats de ces travaux montrent que les espèces de poissons traitées, habituellement communes et peu exploitées, pourraient trouver une voie de valorisation sur un marché haut de gamme

Dry fractionation of chicken fat: Effect of dry fracionation temperature and time on fractions properties

Fats and oils dry fractionation process involves selective crystallization of the higher melting TAG through cooling of the melted fat followed by filtration. Cooling conditions affect crystallization and thus fractions properties but it also has an influence on the separation conditions. Depending on crystal morphology, more liquid is entrapped in the filter cake during filtration thus affecting the properties of this fraction called stearin. We have previously shown that using a slow cooling rate during the nucleation step (low supercooling) allowed the formation of crystals with good filtration properties for chicken fat dry fractionation process. This first step given, the aim of this contribution is to present the influence of final temperature and time on fractions physical and chemical characteristics and filtration properties using experimental design. We determined fractions fatty acids compositions, solid fraction was characterized by its solid fat content versus temperature curve and the liquid one by the cold test. A filtration kinetic was performed and the suspension viscosity measured in order to evaluate filtration properties. Each response Y is described by an equation of the following form: Y = a0 + a1A + a2B + a11A2 + a22B2 + a12AB with A and B representing the coded process parameters (temperature and time). Variations of fraction yields, chemical and physical properties characteristics can be explained as a function of process parameters. The determination of the significance of the coefficients parameters shows that final temperature has a more important effect on fractions yields, chemical and physical properties, and suspension viscosity than time. Similar fractions can be obtained at lower time by reducing temperature. Manipulating temperature and time, liquid fractions with similar properties can be produced over a range of stearin yields and properties. Results presented in this study are useful for monitoring fat dry fractionation process. (Texte intégral

Applications alimentaires de la matière grasse de volaille et produits obtenus

Applications, dans la préparation de produits alimentaires, de fractions des matières grasses de volaille, obtenues par fractionnement à sec de ces matières grasses (chauffage, suivi d'une étape de refroidissement). (Résumé d'auteur

Combined chicken fat dry fractionation and texturization to improve poultry meat products processing

This paper presents chicken fat gelation process based on a calcium-induced gelation of an emulsion composed of sodium alginate, water, and chicken fat. Effects of formulation parameter and and a previous dry fractionation operation on the gel texture and colour are discussed. Results show that both parameters had a significant effect on gel properties, with a predominant effect of alginate on texture and fat unsaturation on colour properties. The texturized fat can be used in the manufacturing of delicatessens products in order to improve pure poultry delicatessen products. The two variables studied must be optimized in relation to product specifications. (Résumé d'auteur