Approche physico-chimique et sensorielle de l’oxydation des lipides en émulsions

International audienc

Collecte et fouille de données olfactives, ou la complexité des données expérimentales

Big data & smart data - Matinales RFI Food for tomorro

Interactions protéines-métaux et stabilité à l’oxydation d’émulsions stabilisées par des protéines

International audienc

How to Visualize a Potential Aromatic Map of a Product in the Odor Space: The Sketchoscent Approach

International audienceThe representation of an odor space is a challenging issue for scientists and professionals working in odor-related activities. Such representations are regularly attempted to provide a common frame of reference to professionals or sensory analysis judges. These initiatives generally classify hierarchically a limited set of odorants in defined categories and turn the odorant space into a simplified representation associated with a graphical visualization. However, these representations do not reflect the actual continuum and overlapping of odors engendered by molecules, their possible description by different levels of accuracy or their belonging to several categories. To overcome these difficulties, we recently proposed the SketchOscent approach (https://oniris-polytech.univ-nantes.io/sketchoscent), an easy-to-use and open-access tool which is founded on a cartographic metaphor of the odor space that reflects the above-mentioned specificities. The work presented here aims to take advantage of this map in order to improve the understanding of the odorant/aromatic perception of products. Indeed, the olfactive perception of a product results from the expression of a set of volatile odorant molecules it contains. The sketchOscent mapping is based on databases that include more than 7700 molecules contained in 8800 products and 380 hierarchical odorant descriptors. It takes into account both sensory and conceptual perceptions. More precisely, it enables to highlight a possible aromatic palette of a product by providing a set of locations in the map, embedding its potential odorants. Following cartographic principles, the map of all locations remains stable in order to keep the user's mental representation and facilitate the comparison between products. Several illustrations are provided to visualize the odor map of different products and compare them. This approach, mainly dedicated to foods, can be useful to pick up relevant terms to describe perceptions or for food-pairing type applications, but may be amended to larger sectors of activities

Approche physico-chimique et sensorielle de l’oxydation des lipides en émulsions*

In many foods, lipids are present as droplets dispersed in an aqueous matrix. This dispersed state favours the oxidation of unsaturated lipids and leads to the degradation of sensory and nutritional qualities of the foods. This work was aimed to (1) investigate the influence on lipid oxidation of physico-chemical characteristics of the lipid-water interface and the aqueous phase in oil-in-water emulsions, designed to mimic dispersion state of lipids in foods, and (2) evaluate the sensory impact of the produced volatile compounds. Analysis of oxidation kinetics of emulsions varying by the nature of the emulsifier, the pH of the aqueous phase or the presence of a hydrosoluble metal chelator, demonstrates the key roles of metal location and reactivity of the emulsifying protein on oxidation initiation and on relative proportions of produced volatile compounds. Most of the volatiles exhibit an odour activity. Their formation lead to an early detection of an odour, which was characterised by cut grass, mushroom, oilseeds, rancid, crushed wood bug, deep fried and painty descriptors. The odour evolved with time as shown by changes in the relative contributions of the intensities of these descriptors. The contribution to the odour of volatile compounds perceived alone or as mixtures was investigated by olfactometric analysis. This work contradicts models based on the charge of the interface and suggests new interpretations for oxidative stability of lipids in complex dispersed media. It also gives practical information about formulation of foods containing unsaturated lipids

Extraction of volatile aroma compounds : a critical step to success in food flavor understanding

Journée Scientifique de l'Association Française des Sciences Séparatives - Section Ouest Atlantiqu

Potentialities of the InnOscent chromatographic system for wine aroma analysis

International audienc

Olfactometric process: new insights in automated acquisition and data treatment

International audienceOlfactometry is a valuable methodology commonly used to investigate odorant active compounds in food aroma profiles. Considering the number of studies using this technique, little is done to improve olfactometric data acquisition, although it is essential for quality outcomes. Efforts were mainly done to automate recording of moment and duration of perceptions but their intensity and description are still often communicate orally, which disrupt judge’s breathing rhythm during analysis. Solutions that integrate intensity and description parameters recording, result in a multiple steps acquisition procedure, scarcely compatible with the transience of the perceptions evaluated during olfactometry experiment. This work aims to present an olfactometry dedicated software developed to simplify the user task, overcoming constraints and bias of existing systems, and associating data treatment capabilities. More specifically the WheelOscent software, coded with Java technologies, implements innovative components:- a data acquisition interface based on adaptable aroma wheels, which permits judges to characterize all parameters related to odors perceived, in a single and intuitive move (patented sensory system),- a data store, which stores collected data into adapted representation describing aroma wheels, experiments, products, judges, and aromagrams, - a data analysis interface, providing a direct and interactive visualization of data resulting from several processing such as data aggregation over judges. The WheelOstat module also provides a straight statistical comparison of aroma profiles.Assessment of the software was performed on food products with complex aroma such as wines or coffee. Providing a good usability for judges, it enables a precise aromatic characterization. Moreover, the statistical comparison module allows to point out singular features of products. Finally, judges take advantage of this wheel aroma presentation, already used for sensory characterization. This consistent presentation for olfactometric and sensory analysis facilitate approaches that attempt to determine contribution of compounds to an overall aroma and apprehend existing interactions

InnOscent chromatographic system : a new potent device for wine aroma analysis

International audienceA new chromatographic device was developed to go further in aroma analysis. Its innovative configuration not only permits to realize classical analysis by gas chromatography coupled with multiple detectors such as mass spectrometry, flame ionization detector and single or dual olfactometric port but also incorporates preparative fraction collection possibilities to recover bespoke aromatic samples. Accordingly, it becomes possible to evaluate the contribution of any compound to the overall aroma of a product