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The impact of cooking, drying and grinding on essential oil content, curcuminoid contents and their bioaccessibility and sensorial quality of Curcuma longa L. was assessed. Sliced fresh turmeric rhizomes (5 mm thick) were air-dried at 60 °C, 40% RH directly or pre-cooked (95 °C/3 min) before drying at different conditions (50, 60 or 80 °C; 40% RH). Dried slices, at 0.11 kg kg−1 db water content, were ground to obtain two powders of different particle sizes (i.e. fine

Ablo is a rice-based bread consumed in Southern Benin. We investigated the impact of pre-cooking conditions and starch characteristics on dough and Ablo physical properties. The solid-like behavior of doughs measured by rheological sweep tests appears significantly negatively correlated to Ablo quality; above a starch gelatinization level (7-8 %), the solid-like behavior of the doughs increased sharply and the fluidity decreased, leading to Ablo of poor quality. A comparison between three rice cultivars tends to show that rice with low amylose content and/or gelatinization temperature gives dough with higher fluidity and Ablo with lower density. In addition, a specific rheological test for measuring simultaneously dough expansion and rheological properties during heating has been developed. It shows that whatever the rice variety, thermal expansion of proofed dough begins and is followed by a dough/crumb transition. This innovative rheological test could be used for studying dough/crumb transition for other types of breads.

L'objectif de ces travaux est d'apporter une méthodologie et des pistes de réflexion en vue de la conception d'appareils de cuisson par contact direct plus performants en termes de consommation d'énergie et de qualité. Une cuisson non maitrisée ou l'utilisation de matériel non-approprié peut conduire à la formation de composés toxiques ou à la transmission par migration de particules vers l'aliment. En effet, ce type de cuisson, bien que très répandu est encore relativement peu étudié d'un point de vue scientifique pour des appareils domestiques. La démarche mise en œuvre est dans un premier temps décrit. Pour évaluer le flux de chaleur transmis lors du contact et suivre les cinétiques de cuisson une expérimentation pilote bien instrumentée a été réalisée afin de suivre des cinétiques de cuisson dans différentes conditions. Afin de bien appréhender les transferts par conduction directe un prototype de flux mètre a été développé. Le but des travaux est d'estimer le flux de chaleur transféré d'une plaque métallique chaude vers un produit alimentaire « froid » déposé sur celle-ci. L'évolution du flux est obtenue par le biais des techniques inverses et l'exploitation de mesures de températures au sein de la plaque chauffante. Le produit alimentaire est mis rapidement en contact, moins d'une seconde et donc, le flux thermique présente de grandes variations. Dans le cadre de cette communication des essais de cuisson d'un produit relativement complexe sont présentés. Il s'agit d'un produit céréalier à pate jaune qui subit différentes transformations couplées à des transferts de chaleur et de masse lors de la cuisson. Les cinétiques de cuisson sont obtenues par le biais de capteurs de température, une mesure en temps réel de la perte de masse et un suivi de la déformation. La confrontation de simulations numériques par un modèle multi-physiques aux cinétiques mesurés montre la pertinence de ces travaux.

In West Africa, household energy transition has so far mainly been synonymous with the conversion from woodfuel to LPG. This paper analyses the failure of 30 years of household energy transition policies in Mali by combining two major frameworks: Multi-Level Perspective (MLP) and Social Practice Theory (SPT). Based on empirical field studies undertaken in Bamako since 1985 and on literature review, two historical narratives are presented, one focusing on the dynamics of the dominant woodfuel regime and the other on changes in cooking practices. The MLP analysis showed that all elements seemed aligned for destabilization of the dominant regime, yet the woodfuel regime has resisted and is maintained. The SPT analysis showed that the stability of cooking, eating and fuel purchasing practices did not converge towards and even opposed the transition to LPG. This paper shows that the MLP and SPT frameworks offer complementary perspectives for understanding transitions in developing countries. It concludes that the definition and implementation of energy policies need to integrate an analysis of daily practices and should consider that energy transition is not synonymous with the replacement of one fuel by another, but with new opportunities to diversify ways of cooking.

The endogenous alpha-galactosidase activity of cowpea seeds was characterized and modelled assuming Michaelian behavior. The aim is to use the resulting knowledge to optimize alpha-galactoside degradation during the soaking-cooking process. In this study, the alpha-galactosidase enzyme from Wankoun cowpea was extracted and its enzymatic activity was analyzed as a function of temperature, pH and the presence of some inhibitors. Enzymatic activity was optimal around 35 °C and a pH of 5.8. Activation and inactivation energy was evaluated at 50 ± 3 and 103 ± 9 kJ.mol−1, respectively. The strongest inhibitor was galactose with an inhibition constant KI of 0.28 ± 0.03 mM. Incubation of the enzyme extract with alpha-galactosides revealed a 10-h lag phase in the early stages that could be due to low pH, the action of inhibitors including galactose and the biosynthesis of alpha-galactosides. After the lag phase, the degradation of each alpha-galactoside occurred without the appearance of any intermediary product. The degradation of alpha-galactosides was observed with a Km of 1.7 ± 0.3 mM for raffinose; 3.6 ± 0.6 mM for stachyose and 15.9 ± 0.1 mM for verbascose. A long soaking step around 35 °C is suggested to maximize the alpha-galactosides enzymatic degradation.

This work was devoted to the understanding of physicochemical transformations and thermomechanical behavior of industrial clay-based mixtures during the firing cycle. A particular focus was made on the development of a viscous phase. For ceramics, the viscous phase plays an important role in the densification mechanism at high temperature and can lead to a decrease of the sintering temperature. Therefore, it is very important to understand its interaction with the clay matrix. To this end, a specific approach based on a combination of standard characterization techniques (dynamic scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal analysis (TGA-DTA), mass spectroscopy (TGA-MS), and thermomechanical analysis (TMA)) and advanced one (acoustic resonance, AR) was used. The overall thermal behavior of three industrial clay-based mixtures during firing was investigated using a combination of dynamic characterization techniques, in order to establish a relationship between these transformations and the development of the viscous phase. Thus, the formation of the viscous phase and the associated effects in terms of densification acceleration were particularly revealed by following the damping of AR signals and by dynamic high-temperature SEM observations. Further analysis using TEM at room temperature revealed that the glassy phase resulting from the solidification of the viscous phase is predominantly composed of silicon, aluminum, oxygen, and potassium with traces of iron. Moreover, the kinetic modeling approach based on the experimental results of TMA analysis has contributed to a better understanding of the kinetic and mechanisms in the sintering step. The results obtained are original as they highlight the contribution of the viscous phase in the mechanisms involved in sintering, compared to existing models. The influence of different fluxing oxides on the mechanisms associated with the presence of the viscous phase in an industrial clay-based mixture was also investigated. From this study, it will be possible to determine to which extent the temperature of the development of the viscous phase could be controlled, in order to reduce the firing temperature. The results revealed that the temperature at which the viscous phase appeared and the mechanical properties of the produce clay-based materials depend mainly on the nature of the additive and its physical properties. The study demonstrated that both an improvement in the densification kinetics and a decrease of the densification temperature can lower the firing temperature. Introducing a higher amount of B2O3 decrease the temperature of the viscous phase formation of 80°C. Otherwise, a higher amount of K2O and Fe2O3 improve the densification kinetics and thus leads to a reduction of 20°C in the firing temperature. This original approach allowed an outstanding description of complex mechanisms involved during the firing of clay-based mixtures, specifically during the sintering step, bringing new insights in regards to the state-of-the-art. In particular, this approach depicted the dynamics of the physicochemical transformations that were until now only an assumption. Also, this approach can be beneficial in the terracotta industry as it can be used to predict and tailor the final microstructure of clay-based materials and promote a decrease in their firing temperature.; Ce travail est consacré à la compréhension des transformations physico-chimiques et du comportement thermomécanique de mélanges argileux industriels lors de la cuisson, notamment en lien avec le développement de phase visqueuse. En effet, la phase visqueuse joue un rôle important à haute température dans les produits de terre cuite, car elle est conjointement liée à la consolidation du matériau et peut conduire à une diminution de la température de début de frittage. Il est alors important de bien comprendre son interaction avec les autres constituants du mélange de fabrication. À cet effet, une démarche basée sur la combinaison de techniques expérimentales standard (analyses thermiques (ATG - ATD), spectrométrie de masse (ATG - MS), dilatométrie (ATM), diffraction des rayons X (DRX), microscopie à balayage dynamique (MEB), et microscopie électronique à transmission (MET)) et avancée (résonance acoustique en température) a été mise en œuvre. Le suivi du comportement global de trois mélanges argileux industriels lors de la cuisson a été réalisé grâce au couplage de techniques expérimentales in-situ, permettant ainsi d’établir une relation entre ces transformations et le développement de phase visqueuse. La formation de la phase visqueuse et les effets associés en termes d’accélération de la densification ont été mis en évidence avec le suivi de l’amortissement de signaux de résonance acoustique et d’observations à haute température au MEB. Des observations complémentaires à température ambiante au MET ont montré que la phase vitreuse résultant de la formation de phase visqueuse à haute température était composée d’oxygène, de silicium, d’aluminium et de potassium ainsi que des traces de fer. Par ailleurs, l’approche de modélisation basée sur les résultats expérimentaux de l’ATM a contribué à une meilleure compréhension de la cinétique et des mécanismes mis en œuvre au cours du frittage. Les résultats obtenus sont originaux car ils mettent en évidence la contribution de la phase visqueuse dans les mécanismes impliqués dans le frittage comparés aux modèles précédemment développés dans le cadre du projet de laboratoire commun RESPECTc sur des mélanges argileux. L’étude de l’impact de différents oxydes sur les mécanismes associés à la présence de phase visqueuse sur un mélange argileux industriel a aussi été réalisée. L’objectif applicatif à terme est de voir dans quelle mesure les températures d’apparition de la phase visqueuse pourront être contrôlées pour abaisser la température de cuisson des produits. Les résultats ont montré que la nature de l’additif et ses propriétés physiques ont une influence non négligeable sur la température d’apparition de la phase visqueuse et sur les propriétés mécaniques. L’étude a démontré qu’une amélioration de la cinétique de densification et une diminution de la température de début de densification peuvent toutes les deux conduire à un abaissement de la température de cuisson. L’ajout de B2O3 en grande quantité peut permettre un abaissement de la température de cuisson par une diminution importante, de l’ordre de 80°C, de la température d’apparition de la phase visqueuse. En revanche, la présence en grande quantité d’oxyde de potassium et de fer améliore la cinétique de densification et conduit à une réduction de 20°C de la température de cuisson. Cette approche originale a permis une compréhension fine des transformations physico-chimiques se produisant au cours de la cuisson de mélange argileux, spécifiquement lors du frittage en se basant sur des hypothèses qui donnent accès à la dynamique de ces transformations. De plus, elle peut être bénéfique pour l’industrie de la terre cuite dans la mesure où elle peut permettre, dans une certaine mesure, de prédire et orienter la microstructure finale et favoriser une diminution de la température de cuisson des produits de terre cuite.

Cet article examine le processus de la nutrition et son principe central de parenté qui porte la nourriture vers le nourri, et les transformations que lui apporte Platon pour fonder le passage du mécanisme d’absorption du nutriment à celui du mouvement du monde visible, de l’âme intelligible, de son éducation, et de la maladie. La nutrition, dont les traits fondamentaux sont hippocratiques, peut être qualifiée de paradigme épistémologique pour connaître la nature du Tout et des vivants qu’il abrite.

Lors du Ve Symposium interuniversitaire sur les céramiques antiques de Lezoux, organisé du 17 au 25 octobre 2020, par la Maison des Sciences de l’Homme de Clermont-Ferrand et plusieurs partenaires, et dans le cadre des RDV de la Station biologique de Besse, Armand Desbat a donné une conférence sur le thème « De la terre au pot, regards croisés sur les techniques céramiques traditionnelles », le mercredi 21 octobre 2020 au cinéma de Besse.Directeur de recherche au CNRS, Armand Desbat propose ici un tour du monde des différentes techniques de façonnage des céramiques dans l'artisanat traditionnel. Un voyage dans le temps et l'espace...

"Cooking ware" is a special category of pottery. It corresponds to cooking-pots, casseroles, frying pans, etc. It is characterized by its particular function of heating and cooking. Therefore, it stands out from the rest of pottery because of its appearance and properties. Easily recognizable, it is found very frequently in excavations and on all types of sites. In the south of the Levant, between the 1st century BC and the 8th century AD, paradoxically, it has never been the subject of major works. Current knowledge on the subject is, in fact, very incomplete. In order to try to remedy as well as possible this gap in our knowledge of cooking vessels, too often neglected, the present study is based on a work of classification. If the cooking pots may appear very diversified at first sight, it is possible to highlight recurrent forms and large morphological series. Once the typology has been established, it is then possible to look at many other issues in greater detail. Our attention will focus mainly on questions related to dating, but also to their production, both at the level of the methods of shaping and of workshops themselves. In addition to these two aspects, the cooking pots also appear to have been the subject of trade, sometimes on a very large scale. The pot cannot be dissociated from its primary function. Through archaeology and ancient sources, it is possible to gain a better understanding of the food practices of the South-Eastern populations., La céramique dite "culinaire" est une catégorie particulière de la commune. Elle correspond aux marmites, casseroles, poêles, etc. Elle se caractérise par sa fonction particulière qui est de chauffer et de cuire. De ce fait, elle se détache nettement du reste de la poterie par son aspect et ses propriétés. Facilement reconnaissable, elle est trouvée très fréquemment lors des fouilles et sur tout type de site. Pour le sud du Levant, entre le Ier s. av. J.-C. et le VIIIe s. ap. J.-C., elle n'a paradoxalement jamais fait l'objet de grands travaux. Les connaissances actuelles sur le sujet sont, de fait, très lacunaires. Afin d'essayer de remédier au mieux à cette mauvaise connaissance des récipients de cuisson, trop souvent négligés, la présente étude repose sur un travail de classification. Si la culinaire peut apparaître au premier abord très diversifiée, il est possible de mettre en évidence des formes récurrentes, de grandes séries morphologiques. A partir de l'établissement de la typologie, il est alors possible de se pencher, plus en détail, sur de nombreuses autres problématiques. Notre attention se portera principalement sur les questions liées à la datation, mais également à leur production, que ce soit au niveau des méthodes de façonnage que des ateliers mêmes. Outre ces deux aspects, la culinaire apparaît également comme ayant fait l'objet d'un commerce, parfois à très grande échelle. On ne peut pas dissocier le récipient de sa fonction première. Au travers de l'archéologie et des sources antiques, il est possible de mieux appréhender les pratiques alimentaires des populations sud-levantines.

Ablo is a rice or maize-based steam-cooked bread-like product, very popular in Benin, Togo and Ghana. This study optimized the processing steps of rice ablo using response surface methodology. The effect of precooking (proportions of flour and water, duration), kneading (wheat level, duration), fermentation (yeast level, temperature, duration) conditions to dough (gelatinization level, fluidity, proofing) and ablo (ethanol content, pH, density, cooking expansion, firmness, alveolar structure) properties were studied. It was demonstrated that ablo texture can be controlled by the fluidity of the fermented dough. Fluid fermented dough (at least 0.5 cm/s) expands adequately during steam-cooking and results in a less dense ablo in line with commonly consumed ablo. The optimal dough fluidity comes from a low gelatinization level of the precooked dough (less than 20%) and an intense fermentation (high yeast dose and long fermentation). Surprisingly, dough proofing appears to have no effect on final ablo expansion.

International audience; Low pungency, high aromatic potential and red color, give to Piper borbonense its originality when compared to Piper nigrum. Effects of blanching, sweating and drying on these characteristics were assessed. The three operations had no impact on the concentration of piperine and essential oil but affected the composition of essential oil slightly and considerably affected the color of the pepper. The ''wet process " , including blanching, sweating and drying, had the largest impact on the composition of aroma, increasing para-cymene content by 89% and reducing safrole content by 33% in dried pepper compared to fresh. Blanching increased the drying rate thus reducing drying time. Drying had a major impact on color, which changed from red to brown. The biggest differences observed led to reductions of 2.2, 7.9 and 8.4 units in L ⁄ ,a ⁄ and b ⁄ values, when chromatic values measured in fresh pepper were compared to those of dried pepper.

The paper presents a simulation methodology to predict the curing of composites inside an industrial micro-wave Hephaïstos© oven. The methodology is based on a weak coupling method which chains an electromagnetic simulation of the MW oven containing the composite part and a heating-curing simulation of the composite part. These simulations respectively run with the industrial softwares CEM One® and PAM-COMPOSITES® from ESI. In a second step, thesesimulations are used to build a parametric solution to address magnetron optimization strategy or real-time process control issues., Ce papier présente la méthodologie développée pour construire une plateforme de simulation spécifique pour le procédé de cuisson de pièces composites dans un four micro-onde industriel de type Hephaïstos©. La méthodologie est basée sur un couplage faible entre une suite de simulations, tout d’abord électromagnétique dans le four micro-onde contenant la pièce composite et son moule, suivi d’une simulation chimico-thermique de lacuissonde la pièce. Ces simulations ont été réalisées respectivement sur les solveurs industriels ESI CEM-Ones® et ESI PAM-COMPOSITES®. Dans un second temps, les résultats de ces simulations ont été utilisés pour construire une solution paramétrique du chauffage pouvant être utilisée pour effectuer de l’optimisation du cycle de chauffe micro-onde ou un contrôle du procédé en temps réel. Ces derniers demandent en effet des temps de calcul brefs, une adaptation à l’évolution de la courbe de puissance, ainsi qu’une prise en compte de l’historique de cuisson de la pièce.

Although breeders have made significant progress in the genetic improvement of cassava (Manihot esculenta Crantz) for agronomic traits, lack of information on heritability and limited testing of high-throughput phenotyping methods are major limitations to improving root quality traits, such as softness after cooking, which rank high among Ugandan consumers. The objectives of this study were to determine heritability for softness of cooked cassava roots, and quantify the relationship between penetrometer and consumer testing methods for phenotyping softness of cassava roots. Softness defined as the maximum force (N) needed to penetrate cooked root samples using a penetrometer, was evaluated at four cooking time intervals: 15, 30, 45, and 60 min on 268 cassava genotypes. Estimates of broad-sense heritability (repeatability) ranged from 0.17 to 0.37, with the highest value observed at 45 min of cooking time interval. In the second study involving 135 cassava consumers from Kibaale district in Uganda, penetrometer measurements of cooked roots from six cassava varieties were found to be in strong agreement (r2 = 0.91; P-value = 0.003) with ordinal scores of root softness from consumer testing. These results suggest that: (a) softness of cooked cassava roots is a trait amenable for evaluation and selection; and (b) a penetrometer can readily be used for assessment of cooked root softness. These findings form the basis for operationalising the routine assessment of root softness in cassava breeding trials, an output that will enhance ongoing efforts to breed for desired end-user root quality traits.Key words: Breeding, cooking, Manihot esculenta

La Résonance magnétique nucléaire à bas champ est une méthode spectroscopique qui renseigne sur la nature et l'état des molécules dans tout type de produits. Elle est développée au laboratoire IRMFood de l'IRSTEA de Rennes pour des applications en agro-alimentaire dans un contexte d'optimisation de la qualité des produits mais aussi des procédés de fabrication. La cuisson du pain est un procédé sur lequel l'équipe travaille depuis plus de 10 ans. C'est dans ce contexte, qu'un four de cuisson à pression réduite (vide partiel) destiné au secteur de la boulangerie, viennoiserie et pâtisserie, a été mis au point. Cette nouvelle technologie améliore la levée de la pâte, réduit sa perte en eau et permet un gain énergétique significatif du procédé de cuisson. Son aptitude à améliorer l'expansion des pains a été testée sur une recette sans gluten. La pâte et les pains produits ont été caractérisés par RMN à bas champ, car cette méthode est l'une des rares à pouvoir étudier, de façon non invasive et non destructive, en temps réel, les transformations biochimiques de la pâte pendant la cuisson et les propriétés physico-chimiques de la mie de pain au cours de son stockage. Puisque le point d'ébullition de l'eau diminue à pression réduite, on s'attendait à ce que sa répartition dans la pâte et les interactions qu'elle a avec les autres constituants (principalement l'amidon) seraient différentes de celles observées dans un pain cuit sous pression atmosphérique. Or, peu de changement dans la gélatinisation et la rétrogradation de l'amidon ont pu être mesuré lorsque la pâte était cuite sous vide partiel. Des mesures parallèles en rhéologie sur de la mie de pain fraichement cuit ont montré que ses propriétés mécaniques étaient principalement influencées par la fraction gazeuse de la mie (bulles). Ces travaux ont également permis de mettre en avant les capacités de la RMN à bas champ pour suivre les phénomènes de cristallisation de l'amidon liés au rassissement du pain.

International audience; This chapter provides a state-of-the-art review of the diversity and dynamics of consumer demand with respect to the eating quality of rice worldwide. Quality includes both tangible measurable factors (rice characteristics) and the context of consumption. The main sensory attributes evaluated around the world are described, and their relationship with the diversity of consumer demand is discussed. Instrumental methods for predicting quality measured on either raw or cooked grains are reviewed. The changes that occur in the rice grain during cooking are described along with a modeling approach able to predict the changes and their spatial distribution in the rice grain during cooking. This approach can be used to link consumer demand with cooking conditions and grain quality.

Over the 65–100 °C range and at a water content of 1.6 kg kg−1 db, a comparison was conducted between plantain paste (dispersion made of flour and water) and pulp pieces after cooking to evaluate their respective degree of starch gelatinization (α) and in vitro digestibility. Below 76 °C and at 100 °C, the gelatinization behaviour of starch into pulp pieces and paste was similar, whereas at 85 °C a significant mean relative difference was observed in between. For α in the 0–1 range, pieces of plantain pulp exhibited a lower rapidly digestible starch fraction (30%) and a higher resistant starch fraction (33%) than the flour paste, suggesting some structural effects. Both Weibull and exponential models showed a good fit for α over temperature range and starch digestibility fractions over α. Although no explicit relationship was established between the intact pulp structure and grinded flour state of plantain, the evaluation of the degree of starch gelatinization and digestibility of a plantain flour paste, could be used to predict the gelatinization and digestibility behaviour of plantain starch in entire pieces of pulp.

Depuis les années 1980, la surspécialisation de l’archéologie, nécessaire et découlant naturellement de l’évolution technique des méthodes, efficace à bien des égards, a néanmoins entraîné une forme d’opacité entre les différentes composantes de notre discipline. Les sujets de recherche eux-mêmes s’en voient affectés, cloisonnés dans un cadre qui les limite à type de matériel choisi. Peut-être est-ce de ce fait que l’archéologie a aujourd’hui tendance à se tourner, de plus en plus, vers un travail descriptif plus que sur des questions générales, perdant sans doute au passage le grand public qui en est pourtant l’avenir en ces temps de crise. Est-il néanmoins possible d’envisager, sans pour autant annuler l’effet positif des spécialités, une autre forme d’approche ?Illustrant les limites qu’implique une vision trop cloisonnée, la question des capacités de cuisson en milieu castral au bas Moyen Âge ne peut être résolue sans déterminer une approche méthodologique transdisciplinaire (« trans- » dans le sens où elle ne peut s’encombrer du cloisonnement entre les disciplines). Il est en effet nécessaire d’aborder à la fois la taille des morceaux de viande lorsqu’ils sont cuits et donc leur découpe, la capacité de contenance ainsi que les traces de feu ou de résidus alimentaires des récipients céramiques, et les types de foyer sur lesquels s’opèrent les cuissons, pour ne citer que quelques exemples.Sans tomber dans l’idée que l’on peut être spécialiste de tout, cette communication propose d’aborder les pratiques culinaires à travers une méthode qui à la fois s’appuie sur le savoir-faire des spécialistes et permet d’interroger le matériel avec des questions propres à la problématique de recherche. Since the 1980s, over-specialization of archaeolgy has been creating barriers between researchers, even when they are working in fields that could be complementary. It seems that, more and more often, a body of work is established before formuating the questions, where it should be the opposite. This archaeological specialisation allows great technical advances, and detailed analysis of the abundant information is necessary, but is also detrimental to the study of more general topics. In this way, we are more often offering descriptions and less often a global understanding, losing the general public for whom we are supposed to work, when the public may actually be the key to geting out of these current crises in archaeology. But can we find another approach without losing the advantages of the specialization?The study of the cooking capabilities in the castle’s kitchen of late medieval nothern France outlines how restrictive a specialized approach would be and the need to find a transdisciplinary approach (where trans- means it try to make disapear the borders between disciplines). Indeed, the size of the meat pieces and the cut of the animal bones, the cooking pottery size, the different type of fireplaces—to present just a few examples—have to be considered all together.While being aware that noone could be a “specialist of everything”, this communication attempts to present the study of the culinary practices through an approach that use the methods and the knowledge of various archaeological specialities (archaeozoologists, archaeobotannist, field archaeologist, ceramologist…), while asking new questions of the material evidence, linked to a more general topic.

National audience

The Meat Standards Australia (MSA) grading scheme has the ability to predict beef eating quality for each ‘cut×cooking method combination’ from animal and carcass traits such as sex, age, breed, marbling, hot carcass weight and fatness, ageing time, etc. Following MSA testing protocols, a total of 22 different muscles, cooked by four different cooking methods and to three different degrees of doneness, were tasted by over 19 000 consumers from Northern Ireland, Poland, Ireland, France and Australia. Consumers scored the sensory characteristics (tenderness, flavor liking, juiciness and overall liking) and then allocated samples to one of four quality grades: unsatisfactory, good-every-day, better-than-every-day and premium. We observed that 26% of the beef was unsatisfactory. As previously reported, 68% of samples were allocated to the correct quality grades using the MSA grading scheme. Furthermore, only 7% of the beef unsatisfactory to consumers was misclassified as acceptable. Overall, we concluded that an MSA-like grading scheme could be used to predict beef eating quality and hence underpin commercial brands or labels in a number of European countries, and possibly the whole of Europe. In addition, such an eating quality guarantee system may allow the implementation of an MSA genetic index to improve eating quality through genetics as well as through management. Finally, such an eating quality guarantee system is likely to generate economic benefits to be shared along the beef supply chain from farmers to retailors, as consumers are willing to pay more for a better quality product.

International audience; This study characterized the size distributions of eye-shaped bubbles as a function of different number of fat layers (NFL) (4-128) in Danish pastry. This allowed for the first time, without which it is difficult to objectively define a coarse crumb texture typical of craft products, a too fine crumb texture typical of over-lamination, or and the sizes of the bubbles typical of maximum lift. Ten to 20 mm wide bubbles did not differ in number with the NFL, except in over-laminated pastry in which their number decreased. Five-10 mm wide bubbles increased in number between 16 and 48 fat layers and explained the difference in crumb texture (more regular) and lift (+16%). One to 5 mm wide bubbles, rather round in shape, increased with the NFL, contributing to more regular crumb texture and predominated in over-laminated pastry. The number of eye-shaped bubbles was then correlated with the number of fat fragments, giving a ratio of 5 of the widths of bubbles to fat fragments. This result was logical knowing that bubbles also increase in size in the fat layers, as demonstrated earlier by MRI monitoring of Danish pastry during proving. This result also offered the opportunity of optimizing the alveolar structure of finish Danish pastry from the lamination step, using the degree of fat fragmentation at this step. The impact of these results on the usual view of bubble growth in Danish pastry is last discussed.

International audience; The frequency of pork hams with PSE-like zones is a major issue for the processed meat sector in France, despite recent improvements in the slaughter techniques and systematic sorting on the ultimate pH value of hams. Halothane genotype, still widespread in its heterozygous form, may play a significant role in this issue [1]. On the other hand, a recent work described at a molecular level a possible link between oxidative stress and the specific development of PSE-like zone [2]. From this hypothesis, an experimental design was carried out at the IFIP Experimental Station to evaluate the effect of antioxidant supplementation in pig diet on the appearance of PSE-like zone and more generally on the overall ham quality before and after cooking process.

A 1D mechanistic model was developed to describe water, deformation, amylose transport and starch gelatinization inside rice grains during cooking. Four migrating species were considered: two water populations according to the state of the starch, soluble amylose and an insoluble solid phase network. Three coupled mass transport PDE were formulated assuming diffusional mass transport and using a Lagrangian-Eulerian framework. The model integrates the convective effect of a water flux on the transport of soluble amylose. Rice grain deformation was the result of both water-induced swelling and erosion of the surface of the solid phase, assuming a zero-order kinetic process. The model was adjusted on a milled Chil-bo rice cultivar steeped in excess water at 75 °C and 95 °C. After 30 min at 95 °C, which is the standard cooking time, water uptake, leaching of soluble amylose and the amount of eroded material were 3.15 kg kg−1 db, 5.0% and 15.5% (w/w) respectively. Using the predicted distribution of species within the grain, the model could help to control the texture of cooked rice. (Resume d'auteur)

In this paper, exposure to Polychlorinated biphenyls (PCBs) related to bovine meat consumption is assessed based on multiples sources of data, namely data collected within the national research project "SoMeat" that objectively assesses the potential risks and benefits of organic and conventional food production systems in terms of contaminants respective contents. The work focuses on dioxin like PCBs in bovine meat in France. A modular Bayesian approach is proposed including measures after production, effect of cooking, levels and frequency of consumption and effect of digestion. In each module, a model is built and prior information can be integrated through previously acquired data commonly used in food risk assessment or vague priors. The output of the global model is the exposure including both production modes (organic and conventional) for three different cooking intensities (rare, medium, and well-done), before digestion and after digestion. The main results show that organic meat is more contaminated than conventional meat in mean after production stage and after cooking although cooking reduces the contamination level. This work is a first step of refined risk assessment integrating different steps such as cooking and digestion in the context of chemical risk assessment similarly to current microbiological risk assessments.