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Exploring the Relationship Between Astringency and Lingual Tactile Sensitivity
No full textThis research leading to these results was funded by the “FlaveurVeg” grant, from Carnot Qualiment© (DOI: https://doi.org/10.17180/h5gd-gk88).International audienceWhen lingual tactile sensitivity has received less attention than taste, it plays a critical role in food textural preferences and eating behavior. The anterior tongue, rich in specialized mechanoreceptors, is particularly sensitive to tactile stimuli. This study investigated inter‐individual variability in lingual tactile sensitivity and its potential relationship with astringency sensitivity. To this end, three distinct aspects of lingual tactile sensitivity as well as tongue strength were assessed in 39 subjects (26 F, mean age = 35 ± 5 years). The three tactile dimensions included: (i) light touch (assessed with Von Frey monofilaments in a one‐point pressure test), (ii) spatial perception (two‐point discrimination test), and (iii) roughness sensitivity (using paper coupons with varying grit sizes). Astringency detection thresholds, previously determined using tannic acid solutions, were available for all participants. Results revealed significant inter‐individual variability across all tactile measures. Notably, no significant correlations were found between the three different tactile sensitivity tests (light touch, spatial perception, roughness), suggesting that each one captures a distinct aspect of lingual tactile functions. Tongue strength was not associated with either tactile or astringency sensitivity. A key finding was a significant positive correlation between the tannic acid astringency detection threshold and the pressure discrimination threshold, suggesting that astringency sensitivity may involve a tactile component possibly mediated by the slowly adapting mechanoreceptors (SAI and SAII types). However, no relationship was found between astringency sensitivity and roughness sensitivity. The study emphasizes the need for standardized methods to better understand distinct dimensions of lingual tactile sensitivity and their influence on food texture perception
Characterization and transcriptome analysis of mercury-resistant Pseudomonas canadensis isolated from a chlor-alkali contaminated soil revealed mer-independent detoxification pathways
No full textInternational audienceHuman activities have caused severe soil pollution through the discharge of pollutants, reshaping microbial communities. Among soil microbiota, the genus Pseudomonas exhibited remarkable tolerance to multiple contaminants, including mercury (Hg). This study compared the Hg resistance mechanisms of two Pseudomonas canadensis strains isolated from contrasting environments: a resistant isolate from the rhizosphere of Hgcontaminated soil and a control strain from unpolluted soil. The strain originating from a Hg-enriched soil showed significant biovolatilisation capacity and 20-fold higher Hg resistance compared to the strain isolated from an unpolluted environment. Biomass and necromass responses indicated that the control strain primarily relied on passive resistance, while the resistant strain exhibited active detoxification. Transcriptomic analysis revealed a rapid upregulation of genes associated with metal detoxification and efflux pathways in the resistant strain, independently of the mer operon, suggesting alternative resistance mechanisms. In contrast, the control strain exhibited transcriptional signatures of cellular stress, with increased thiol metabolism, DNA repair, and oxidative stress responses. These findings demonstrate that long-term Hg exposure selects for functional adaptations that sustain resistance in microbial populations. This work sheds new lights on Hg tolerance in P. canadensis and highlights the potential of naturally adapted strains for bioremediation strategies
Rapid identification of bacterial spores by Raman and OPTIR infrared spectroscopy using chemometrics and machine learning
No full textInternational audienceCo-localized IR/Raman O-PTIR imaging enables rapid, label-free identification of Bacillus spores, discriminating species (B. cereus, B. subtilis, B. coagulans) and strains within a specie.This approach could be extended to identify additional strains/species (pathogenic B. cereus), other genera (Clostridium) and vegetative bacteria. It will allow to investigate whether spectra can distinguish sporulation conditions or germination stage.The next step in development will be to determine the minimum number of informative wavelengths in order to design simplified, sensor-based measurements
Optical photothermal infrared (OPTIR) spectroscopy assisted by machine learning for lactic acid bacteria identification at strain level
No full textInternational audienceLactic acid bacteria (LAB) are widely used in food, health, and biotechnology sectors, where accurate strain level identification is critical. Conventional methods, such as 16S rRNA sequencing, PCR-based fingerprinting (RAPD, AFLP), and MALDI-TOF mass spectrometry are powerful tools to identify bacteria at species level but often fail to resolve closely related strains due to limited taxonomic resolution, protocol sensitivity, or database dependence. In this study, we evaluated the capacity of Optical photothermal infrared (OPTIR) spectroscopy, a single-cell vibrational imaging technique, combined with supervised neural networks, to classify LAB at both species and strain levels. A total of 13 strains were analysed, including five Lactiplantibacillus plantarum, one Lactiplantibacillus pentosus, one Limosilactobacillus fermentum, three Lacticaseibacillus casei/paracasei, and three Streptococcus thermophilus, covering both intra- and inter-species diversity. Spectral data from LAB were acquired using a mIRage LS OPTIR system, preprocessed, and used to train a fully connected neural network for each level. The models achieved macro F1-scores of 97% for species level and 91% for strain level classification. These results demonstrate the potential of OPTIR, when integrated with machine learning, as a robust tool for high-resolution bacterial classification, with promising applications in microbiological quality control, probiotic selection, and microbial ecology
From Sharing to Capitalizing: Evaluating the Rise of Airbnb in Housing Prices
No full textInternational audienceThis paper investigates the causal impact of short‐term rentals (STRs) on housing prices across French municipalities in 2018−2019. Using Airbnb data and a novel demand‐shock instrument, we isolate exogenous variation in STR supply. A 1% increase in STR density raises local housing prices by an average of 11%, with stronger effects in densely populated, supply‐constrained cities and in non‐touristic rural areas. Results also show substantial heterogeneity between professional and non‐professional hosts, the latter driving most of the capitalization effect. By combining platform and administrative data, the paper provides new evidence on how tourism‐driven housing demand shapes real‐estate markets
Human emotional odours influence horses’ behaviour and physiology
No full textInternational audienceOlfaction is the most widespread sensory modality animals use to communicate, yet much remains to be discovered about its role. While most studies focused on intraspecific interactions and reproduction, new evidence suggests chemosignals may influence interspecific interactions and emotional communication. This study explores this possibility, investigating olfactory signals in emotional contagion from the example of human-horse interactions. Cotton pads carrying human odours from fear and joy contexts, or unused pads (control odour) were applied to 43 horses’ nostrils during fear tests (suddenness and novelty tests) and human interaction tests (grooming and approach tests). Principal component analysis showed that overall, when exposed to fear-related human odours, horses exhibited significantly heightened fear responses and reduced interaction with humans compared to joy-related and control odours. More precisely, when exposed to fear-related odours, horses touched the human less in the human approach test, gazed more at the novel object, and were more startled (startle intensity and maximum heart rate) by a sudden event. These results highlight the significance of chemosignals in interspecific interactions and provides insights into questions about the impact of domestication on emotional communication
Co-produire des connaissances et des outils pour des démarches préventives et opérationnelles en gestion agroécologique des adventices Partie I. Acquisition de données et synthèse dans des outils numériques
No full textAccompagner l’évolution des systèmes agricoles vers une moindre dépendance aux produits phytopharmaceutiques en se concentrant sur les méthodes préventives et sur les évaluations élargies des pratiques de protection des cultures et en les appréciant à travers leur durabilité. Dans ce numéro, nous abordons la conception d’outils et de stratégies de prévention, le développement de méthodes de lutte non chimique contre différents ravageurs et pathogènes, ainsi que l’évaluation, la définition d’indicateurs, la diffusion et la structuration de pratiques, depuis l’échelle de la parcelle jusqu’à celle des territoires et des filières. Ces projets ont été financés dans le cadre des appels à projets Ecophyto Recherche & Innovation lancés en 2019 : - Les approches globales pour limiter l’utilisation des produits phytopharmaceutiques - Durabilité des systèmes de productions agricoles alternatifs évitant ou limitant l’utilisation des produits phytopharmaceutiques"National audienceLe projet COPRAA visait à produire avec des acteurs de terrain des connaissances, outils et démarches de gestion préventive opérationnelles pour les conseillers et agriculteurs afin de concilier production agricole, rentabilité économique, biodiversité et faible usage, voire absence, d'herbicides en grande culture. Cet article présente (1) la production de connaissances sur les processus biophysiques déterminant les effets des techniques culturales et les régulations biologiques des adventices, avec des expérimentations en conditions contrôlées et au champ, puis (2) la synthèse de ces connaissances dans différents outils numériques (FLORSYS, DECIFLORSYS, OPTIFLORSYS, OdERA). L'évaluation et la conception d'idéotypes variétaux et systèmes de culture sera présentée dans la partie II de cet article
Assessing the non-target effects of herbicides on field margin plant communities after controlling for soil, climate, local context and landscape metrics
No full textInternational audienceHighlights: • We used a national dataset of 500 sites monitored yearly from 2013 to 2018. • We analysed the effects of herbicides on plant margin communities. • Herbicides had a negative effect on richness and nature-value species. • Situations of risk for pesticides drift had a negative effect on margin flora.Abstract: Pesticides are often identified as one of the major causes of biodiversity decline in farmlands. However, our knowledge about this relationship has mostly being inferred from small to landscape-scale studies, or from indirect indicators of agricultural practices at large scales. Here, we used a national network of more than 500 sites monitored yearly from 2013 to 2018 in France to assess the non-target effects of herbicides on field margin plant communities. We used hierarchical generalized linear models to investigate the effects of practices on plant species richness, plant species evenness, proportion of nature-value plants, and proportion of grasses in field margins, while controlling for a large number of possible confounding effects. The intensity of herbicide use had a negative effect on plant species richness, and on the proportion of nature-value plants. In the margin of cereal fields, there was a negative effect of dicotyledon herbicides on richness and a negative effect of grass herbicides on species evenness. We also identified, in some specific crops, a negative effect of non-herbicide treatments on margin flora richness and on the proportion of nature-value plants. The presence of surrounding grasslands had a consistent favourable effect on richness and on the proportion of nature-value plants in field margins. Finally, situations of risk for pesticides drift had a negative effect on margin flora. This study confirms that reducing herbicide use represents a robust lever to maintain the floristic diversity of field margins, which could be combined with strategies reducing the risk of pesticide drift
Decoding sustainable food choices for French consumers: product sustainability attributes prevail over a food category shift. Evidence from a choice intention task
No full textInternational audienceSustainable diets had become an increasingly important topic. This concept considers current and future generations and good conditions of life for all. This multidimensional definition makes its application challenging for consumers in their food choices. In this context, our study aimed to identify the product properties used by French consumers while making sustainable food choices and to explore some facilitators of a transition towards more sustainable choices. A total of 253 French consumers participated in an online food choice intention task that was designed to mimic an online grocery store. A between-group experimental design was used to compare participants' food-choice intentions in the two conditions induced by two different scenarios. In the "sustainable" condition, the scenario referred to a motivation for sustainability, whereas in the "control" condition, it referred to daily food choices. The food categories (fruits, vegetables, meat, fish, etc.) and characteristics (production, processing, packaging and additional information) of the products chosen by the participants were compared between the two conditions. The relative influence of the participants' characteristics and motivations induced by the scenario on food choice intentions was also analysed. The participants' sustainable choices relied mainly on sustainability characteristics (local origin of products, packaging material, fair trade, degree of processing and nutritional quality) rather than on a modification of food categories. Furthermore, the participants exposed to the "sustainable" scenario considered the task more difficult than did the participants in the control group. Finally, the effectiveness of external motivation was moderated by personal characteristics, such as gender and diet
Calcium binding properties of heat-induced pea globulin aggregates
No full textInternational audiencePea protein isolates used in protein-rich foods are typically produced by alkaline extraction and isoelectric precipitation and undergo thermal treatments that can modify protein structure, aggregation, and functionality. This study examines the calcium-binding capacity of heat-denatured pea globulins and the colloidal behavior of the resulting calcium–protein complexes. Protein dispersions (~ 2% w/v, pH 7.5) were thermally treated at 70, 80, and 90 ° C and analyzed in comparison to a non-heated control. Thermal properties (µDSC), surface characteristics (Zeta-potential, surface hydrophobicity), aggregation behavior (turbidity, dynamic light scattering, intrinsic viscosity), and the calcium-binding capacity of the soluble pea protein aggregates, were evaluated by progressive Ca2+ addition (0–20 mM). The denaturation rate increased from 0% to 100% with increasing temperature, leading to higher surface hydrophobicity and a reduced negative charge of the proteins. Calcium-binding of the submicrometric pea protein aggregates via intra-protein association slightly increased compared to unheated protein dispersions. Further Ca2+ addition (> 6–7 mM) promoted an increase of complex size through inter-protein association for low-denatured proteins (unheated or preheated at 70 ° C), whereas smaller and more compact protein complexes were formed in systems preheated at higher temperatures. In all cases, the addition of calcium led to the formation of insoluble protein aggregates; however, preheated systems formed apparently denser precipitates. These findings provide insights into the mechanisms underlying complex formation between pea protein aggregates and added calcium ions, and may support the development of novel plant-based food formulations with tailored texture, stability, and mineral bioavailability