Description sensorielle de la carotte - recherche et mise au point d'une méthodologie

En évaluation sensorielle, la description des caractéristiques organoleptiques d\u27un produit par la méthode de profil sensoriel demande, dans un premier temps, de déterminer les descripteurs qui vont être pertinents dans la caractérisation du produit. Cet article présente les différentes étapes de mise en place d\u27une liste de descripteurs appliquée à la carotte. La carotte étant un produit consommé cru ou cuit et sous différentes formes, trois modes d\u27usage (carotte crue râpée, cuite entière, crue en rondelle...) vont être comparés, afin de déterminer quel est l\u27apport de chacune des méthodes dans la description du produit

French consumer preferences reveal a potential for segmentation in carrot

Gustatory differentiation is one possible means of segmentation. Consumer preferences of carrot were studied within the framework of the CosiVeg project. The characteristics of batches offered for consumer assessment enables their preferences to be evaluated. In preparation for a hedonic test of raw grated carrots that was carried out in autumn 2011, the carrot sensory space was studied in 2010 using 48 batches that were evaluated using quantative descriptive sensory analysis. The cultivars were representative of different types, Nantais, Imperator, Flakkee, coloured carrots and genetic resources. . Significant differences were observed for all criteria, allowing varieties to be grouped based on their sensory characteristics. Texture, flavor and aroma contribute to the “identity” of carrots. Overall aroma is correlated with perceptions of bitterness, sharpness and chemical aroma. Fourteen orange carrot varieties were selected for sowing in 2011. In 2010, although maximum scores were obtained for pungent and bitter attributes, this was not the case in 2011. In spite of this, the selected batches allowed the different profiles of the sensory characteristics of the carrots to be determined. Ten batches of carrot that represented a wide range of variability were tasted by a trained panel as well as a consumer panel; the product was presented as raw grated carrot. The sensory measurements obtained were used to map preferences, underlining preferences for a carrot that is juicy, aromatic and sweet. However bitter and chemical flavour carrots were not appreciated. Three types of consumer exist each having different expectations in terms of quality. Almost 20 % of people questioned are looking for a high quality product, for 33 % of consumers carrots are a staple food and they have no specific expectations and 48 % are satisfied with the current product but are potentially interested by a product that would distinguish itself as regards to quality. It means that segmentation with a high gustatory quality will be of interest for one consumer for 5

Qualité organoleptique de la carotte : variabilité des critères sensoriels selon le type variétal

La différenciation gustative est une voie possible de segmentation. L\u27étude a porté sur la variabilité des critères sensoriels dans le matériel végétal. Trente-trois varié - tés des types Nantais, Imperator, Flakkee, de carottes de couleur et de ressources génétiques ont été caractérisées en analyse sensorielle descriptive quantitative et par des mesures physico-chimiques. Des différences significatives pour tous les critères existent et permettent de regrouper les variétés sur la base de leurs caractéristiques sensorielles. Texture, saveur et arôme contribuent à la typicité de la carotte ; l\u27arôme global est corrélé aux perceptions d\u27amer, de piquant et d\u27arôme chimique. La mesure des sucres ne permet pas d\u27évaluer la perception en bouche du sucre du fait de l\u27influence du potentiel d\u27amertume

Variation factors involved in carrot sensory appreciation

Sensory analysis is an indispensable tool for understanding the consumers and promoting segmentation in a product such as the carrot. However, one must have first a good knowledge of the sensory space of the carrot, and identify the sources of variation involved in the sensory characterization. Trials were conducted on two years in 2010 and 2011 and two production sites in France. The overall sensory space was characterized from 48 batches representing a wide genetic diversity. This has enabled us to identify varieties that opposed the main criteria i.e. texture, including juicy trait, sweet perception and the potential of bitterness, spicy and chemical aroma. On a smaller sample of orange carrot, two years of tests have highlighted variations due to the production site and varieties, which were modulated by annual differences. The observed variation underlines the need for more research on explaining the causes such as the development cycle and the pedoclimatic conditions.

Sauter-Schwinger like tunneling in tilted Bose-Hubbard lattices in the Mott phase

We study the Mott phase of the Bose-Hubbard model on a tilted lattice. On the (Gutzwiller) mean-field level, the tilt has no effect -- but quantum fluctuations entail particle-hole pair creation via tunneling. For small potential gradients (long-wavelength limit), we derive a quantitative analogy to the Sauter-Schwinger effect, i.e., electron-positron pair creation out of the vacuum by an electric field. For large tilts, we obtain resonant tunneling related to Bloch oscillations.Comment: 4 pages, 1 figur

Les stratégies de contrôle de la qualité sanitaire dans les Organisations de Producteurs de tomates

Our paper deals with free-riding issues in product safety control at the collective marketing level. It focuses on the empirical findings of the exhaustive face to face survey that has been conducted in 2007 by the authors with the quality managers of the tomato growers'unions of France. Our survey was supported by the National Tomato Charter, a regrouping of most of the French tomato growers'unions. Its aim was to identify the differences in monitoring and enforcement practices at the collective marketing level and to search for any group size effect on such practices. A main finding of our paper is that, beyond public regulation and collective rules imposed by the National Tomato Charter, POs implement voluntary control rules for a better control of free riding behavior within the group. Such additional rules differ both in monitoring intensity (measured by the number of pesticide residue analysis performed voluntarily by the group) and in sanction level (applied in case of deviation to the collective rule). Differences in safety control are not only triggered by customers specific requirements but also by group size (measured by the number of growers within the group). Eventually, our paper draws some perspectives for a more in-depth analysis of free riding issues. First, it calls for paying more attention to factors such as intra-group heterogeneity and differences in customers requirements. Second, it underlines the need for a more extensive analysis which includes safety control practices at the production level and wonders whether such practices are a complement or a substitute of control practices at the marketing level. ...French Abstract : Ce texte aborde les problèmes d'action collective dans le contrôle de la qualité sanitaire des produits avant leur mise en marché par les Organisations de Producteurs. Il est une synthèse des résultats de l'enquête menée auprès des responsables qualité de l'ensemble des OP adhérant à la Charte Nationale Tomate sur leurs pratiques de contrôle de la qualité sanitaire des tomates. L'enquête a eu le soutien des responsables de la Charte Nationale Tomate, qui regroupe la quasi-totalité de la production organisée en France. Elle avait pour objectif d'identifier la diversité des pratiques de contrôle au sein des OP et de mesurer l'effet de la "taille de l'OP" sur les modalités de contrôle mises en place. L'enquête montre qu'au-delà des règles communes imposées par la réglementation et la Charte Nationale Tomate, les OP mettent en place des démarches de contrôle diversifiées qui se différencient à la fois par l'importance de la surveillance (mesurée en nombre d'analyses de résidus de pesticides) et par le niveau des sanctions appliquées en cas de dérogation à la règle adoptée. Elle explique enfin la diversité de ces démarches, non seulement par les exigences de la clientèle mais aussi par la taille du groupe (mesurée par le nombre de producteurs). Notre rapport se termine par une discussion sur les améliorations à apporter à ce premier travail. Des précisions sont à apporter tout d'abord sur l'hétérogénéité intra et inter groupes et sur les niveaux d'exigences de la clientèle. Un complément d'analyse est ensuite nécessaire pour mieux caractériser l'effort de contrôle en amont du produit, au niveau de la production et pour étudier la complémentarité ou la substituabilité des deux types de contrôle: contrôle sur les pratiques en production, contrôle sur le produit.PRODUCERS' UNIOS; FREE-RIDING; MONITORING; ENFORCEMENT; CONTROL; PESTICIDE RESIDUES; TOMATO; FRANCE; ORGANISATIONS DE PRODUCTEURS; PASSAGER CLANDESTIN; SANCTION; CONTROLE; RESIDUS DE PESTICIDES; TOMATE