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Pernet Arnaud

Collaborateur technique en Ra&D

Main contract

Collaborateur technique en Ra&D

Changins- Haute école de viticulture et œnologie
Route de Duillier, 1260 Nyon, CH

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Completed

Volatile organic compounds from Essential Oils as a sustainable alternative to pesticides - deciphering the molecular basis underlying their mode of action as plant immunity primers

AGP

Role: Collaborator

Financement: FNS

Description du projet : Downy mildews, caused by oomycetes of the family Peronosporaceae, are plant diseases that can cause tremendous economic losses in many important agricultural food crops worldwide and are responsible for huge amounts of synthetic pesticide applications. The grapevine (Vitis vinifera) is highly susceptible to downy mildew caused by Plasmopara viticola, which represents the most devasting disease in viticulture. To foster a sustainable agriculture, guarantee producer and consumer health, ecological solutions to synthetic pesticides are thoroughly needed. Amongst the most potent natural plant protection products, Essential oils (EOs), have shown their antifungal properties on several agricultural crops. Their performance is however highly depending on application time and method. A direct liquid application has been shown to be very complicated due to phytotoxicity, bad adhesiveness and the hydrophobic nature of EOs, resulting in bad mixability with water and other chemicals. Furthermore, the molecular mechanisms that are triggered by EOs in host-plants and pathogens, that underlie their efficiency, remain poorly understood. The elucidation of the mode of action of EOs on pathogens and their role in plant immunity priming could promote the development of natural ecological plant protection products and aid to better understand plant immunity priming thereby providing fundamental information and new molecular targets for resistance breeding strategies and eventually genome editing. To address those questions, we conducted preliminary experiments, where we could, for the first time, demonstrate that the vapor phase of EO of Oregano vulgare applied in vivo on P. viticola infected grapevines can impede efficiently fungi development. In our study whole genome transcriptomic analysis indicated that the efficiency of EO vapor treatment is to a certain extent due to the priming of plant defense mechanisms inside the host plant. These very promising results highlight the great potential of EO vapor treatments against fungal pathogens and its potential role in plant defense priming. Our study rose several important questions regarding mode of action of EO on host and pathogens, which could not be addressed within the scope of the conducted experiments. The proposed project builds up on our previous findings and has as an overall aim to elucidate the potential of O.vulgare vapor and its different terpenic compounds as plant immunity primers and antifungal agents. The project will combine in vitro, in vivo and in situ experiments on grapevines infected with P.viticola and treated with different volatile constituents of EO vapor. Treatments and sampling will be carried out at different time points before, after and during the infection cycle to decipher precisely the molecular mode of action of EO volatiles on the plant and on the pathogen. RNA-sequencing for differential gene expression will be combined with targeted metabolomic analysis of primary (amino acids, organic acids, sugars) and secondary compounds related to plant immunity, such as phytoalexins (stilbenes, piceids, viniferins) and other phenylpropanoids. The analysis of major hormones such as Salicylic acid, Jasmonic acid, Ethylene, and Abscisic acid, which have been shown to play a role in plant defense mechanisms will help to characterize plant defense priming an to decipher complex hormonal crosstalk's and regulation pattern. A further objective of the project, embedded in the COST-action CA17111, is the integration of the different obtained omic data sets and the development, test and publication of new methods and best practices for the management, integration and analysis of large, heterogeneous data sets from biological experiments. The subsequent metanalysis of produced and existing data from different studies will improve the fundamental knowledge of plant-pathogen-treatment interactions. This will provide new molecular targets for resistance breeding programs and accelera

Research team within HES-SO: Cléroux Marilyn , Rienth Markus , Pernet Arnaud , Vigneron Nicolas , Smit-Sadki Tara , Schönenberger Patrik , Alfonso Esteban

Partenaires académiques: 425 - Oenologie; Rienth Markus, 425 - Oenologie

Durée du projet: 01.06.2020 - 30.04.2024

Montant global du projet: 319'128 CHF

Statut: Completed

Hanging manipulator for gardening applications

AGP

Role: Collaborator

Requérant(e)s: 425 - Oenologie, Burdet Jean-Philippe, 425 - Oenologie

Financement: Innosuisse

Description du projet : This project aim to provide the first commercially attractive solution to support humans and automate vine growing in steep and hardly accessible gardens. The solution is a suspended manipulator sliding on cables over gardens and manipulating plants, opening the door to increase quality and efficiency.

Research team within HES-SO: Delmaire Luc , Burdet Jean-Philippe , Pernet Arnaud , Violet Martha , Smit-Sadki Tara , Noll Dorothea

Partenaires académiques: 425 - Oenologie; Burdet Jean-Philippe, 425 - Oenologie

Durée du projet: 01.08.2021 - 31.01.2023

Montant global du projet: 226'592 CHF

Statut: Completed

Développement d'un capteur utilisant la polarisation diélectrique pour le suivi de la fermentation et du niveau d'extraction durant la production des vins

AGP

Role: Collaborator

Requérant(e)s: 425 - Oenologie

Financement: HES-SO Rectorat

Description du projet : Aujourd'hui, le suivi de fermentation pour la production du vin est réalisé principalement par la mesure de densité, de manière manuelle ou automatique. Pour la production du vin rouge, une étape déterminante pour la qualité du vin final ' l'extraction des composés d'intérêt présents dans la pellicule du raisin (principalement des polyphénols ou « anthocyanes et tanins ») ' a lieu également pendant la phase fermentaire. Actuellement, à part la dégustation, il n'existe pas d'outil performant d'aide à la décision afin de déterminer le moment d'écoulage à cause de la difficulté d'obtenir des informations fiables d'un milieu complexe par une analyse rapide et simple à manipuler. Afin de développer une alternative analytique sensible pour le suivi du niveau d'extraction et d'avancement de la fermentation, un partenariat interdisciplinaire est formé, regroupant les personnels de HES-CHANGINS et de la HEIA-FR, avec des compétences en procédés oenologiques, analyse chimique, électronique appliquée et spectroscopie. Ensemble, les partenaires du projet ont identifié une approche innovante et prometteuse pour la problématique du suivi de fermentation : l'utilisation de la spectroscopie diélectrique. Ayant la possibilité d'utiliser un large spectre d'ondes électromagnétiques, la spectroscopie diélectrique est une technique couramment employée pour la caractérisation électrique (isolants, matériaux avec une haute capacité de stockage d'énergie, '). Depuis quelques années, l'agro-alimentaire bénéficie également du potentiel offert par cette technique, que ce soit pour l'évaluation de la qualité des fruits ou lors de la pasteurisation du jus de pomme. Comme les tests sont rapides et ne détruisent pas la matière, la spectroscopie s'est avérée un outil expérimental adaptée aux mesures en ligne ainsi qu'au suivi de longue durée. Basée sur l'excitation des dipôles (chaines polymères ou molécules) ou des ions en rapport avec les caractéristiques d'un faible champ électrique externe, cette méthode permet la mesure de la permittivité complexe des matériaux polarisables, chaque composant ayant un moment dipolaire caractéristique. Dans ce contexte, nous proposons le projet «WinE-index» («WineExtraction-index ») pour la mise en place d'une corrélation entre les propriétés diélectriques et d'autres caractéristiques ou propriétés physico-chimiques du jus de raisin en phase de fermentation. L'objectif principal du projet est de proposer une technique permettant de tirer à partir d'une évaluation rapide et non destructive des vrais indicateurs par rapport à la composition du vin, pendant la fermentation. Le défi du projet sera la différentiation entre la réponse diélectrique des marqueurs significatifs (éthanol, anthocyanes et tannins condensés) et l'évaluation de l'impact des éléments externes ayant une grande influence sur les propriétés diélectriques, par exemple, des ions (K+), des acides organiques ou des particules solides. En vue de remplir au mieux notre mission - fournir aux oenologues des indicateurs quantitatifs pour compléter leurs analyses sensorielles, afin de leur apporter une réelle aide à la décision - nous proposons le développement d'un capteur innovant, ayant un fort potentiel de marché. Utilisable offline aussi bien qu'intégrable dans des systèmes en ligne, celui-ci permettra de suivre l'avancement de la fermentation en même temps que le niveau d'extraction.

, , , , , , , , , , , , , , , , , , , , , , , Research team within HES-SO: Galé Benjamin Claude Bircher Fritz Cléroux Marilyn Kuster Joël Giorgi Luca Roth Samuel Schneuwly Vincent Bourrier Hervé Monnard Jacques Scheurer Laurence Gomez-Von Allmen Sophie Preda Ioana Froidevaux Lucas Bapst Nicolas Sahli Benoît Trevisani Sandro Gugler Gilbert Carrie Natalia Siebert Priscilla Zeng Liming Pernet Arnaud Balestra Gioele Brodard Patricia Mertenat Muriel

Partenaires académiques: 425 - Oenologie; FR - EIA - Institut ENERGY; FR - EIA - Institut IPRINT

Durée du projet: 17.02.2020 - 17.05.2022

Montant global du projet: 219'980 CHF

Statut: Completed

Technologie analytique de gestion des gaz du vin à l'aide de contacteur membranaire.

AGP

Role: Collaborator

Financement: 425 - Oenologie; HES-SO Rectorat; 425 - Oenologie

Description du projet : Un contacteur membranaire favorise les échanges entre une phase liquide et une phase gazeuse grâce à une membrane hydrofuge comportant des pores de très petites tailles (0.05 µm). La membrane permet donc de diffuser ou d'éliminer avec une grande efficacité et précision des gaz (N2, O2 et CO2) dans un liquide comme le vin (SCHONENBERGER et al., 2014. Am. J. Enol. Vitic.). Grace à des démarches initiées par CHANGINS et soutenue par d'autre pays membres (Allemagne, France), l'Organisation International de la Vigne et du vin a récemment reconnu l'utilisation des contacteurs en 'nologie pour la gestion des gaz des moûts et des vins (RESOLUTION OIV-OENO 499-2013). Cette résolution permettra l'autorisation prochaine de cette pratique. Cependant, il n'existe qu'un seul fabricant au monde (www.liquicel.com) qui produit des membranes qui n'ont pas d'agrément en 'nologie et qui colmatent et s'encrassent rapidement et conduisent à une baisse des flux gazeux. Ce projet se déroulerait en parallèle et en collaboration avec un projet de plus grande ampleur financé par le Fond Unique Interministériel français (projet MO2EV, 48 mois, 5 partenaires privés, 3 partenaires académiques et la HES-SO). La contribution du projet interministériel porterait sur une cotutelle de thèse et le développement de membrane de nouvelle génération adapté au vin. Notre projet aura pour objectif de développer un système automatisé de gestion des gaz du vin, adapté à l''nologie et à la recherche et capable d'être couplé en ligne à une chaine de mise en bouteille. Il proposera : ' La conception et le développement d'un prototype automatisé ' La recherche de nouveaux senseurs plus économique et adapté au vin. ' La mise en place d'un indice standardisé d'efficacité ' Une étude des transferts de gaz et une démonstration de l'intérêt 'nologique ' Une étude sur les modes de colmatage et de nettoyage ' Une réflexion sur la possibilité d'intégrer des électrodes sur la membrane pour mesurer voir modifier son comportement. Ce projet, d'actualité à la fois scientifique et technique, intéresse les caves suisses (Schenk et Provins ont déjà signifié leurs intérêts). Les applications 'nologiques possibles sont nombreuses et porteuses. Enfin et surtout, le développement d'une machine automatisée, fonctionnalisée et moins sensibles à l'encrassement permettrait une expansion dans différents domaine comme les jus de fruits, la brasserie, les sodas ou encore le traitement de l'eau douce ou des eaux usées.

Research team within HES-SO: Veronese Morgane , Ducruet Julien , Bach Benoit , Moreillon Fabien , Menoud Gilles , Schoinas Spyridon , Vorlet Olivier , Audriaz Michel , Passeraub Philippe , Pernet Arnaud , Bourgeois Jean-Pascal , Schönenberger Patrik

Partenaires académiques: hepia inSTI; FR - EIA - Institut ChemTech

Durée du projet: 01.08.2016 - 31.12.2018

Montant global du projet: 126'900 CHF

Statut: Completed

Un système optique à bas coût pour le contrôle automatisé en ligne des fermentations

AGP

Role: Collaborator

Requérant(e)s: 425 - Oenologie, Mira De Orduña Heidinger Ramón, 425 - Oenologie

Financement: HES-SO Rectorat

Description du projet : Batch fermentations are traditionally used in the production of wine and other fermentations and suffer from large concentration gradients that may cause stress to production organisms and affect fermentation success. Fed-batch fermentations address these issues. We demonstrated recently that a certain kind of innovative fed-batch fermentation dramatically reduces yeast stress and acetic acid formation in wine fermentations. This type of vinification is highly innovative and opens significant opportunities for improving fermentations and product quality. However, it requires automatic analysis of sugar concentrations in order to regulate the feeding rate. Lately, the applicant demonstrated that FTNIR is capable of providing continuous in-line analysis of sugar concentrations during fermentations. This method provides the required proof-of-concept, but an alternative technology to a research grade FTNIR has to be found, since the current cost of ~50-70k for the equipment constitutes a barrier for commercial success. The development of the analytical alternatives greatly exceeds the expertise of HES- CHANGINS. As a result, we have formed an interdisciplinary research partnership composed of personnel from HES- CHANGINS and HE-ARC with expertise in industrial microbiology, automation, optical engineering and electronic processing. The partners have identified several synergistic approaches to reduce overall system cost. These comprise multiplexing the liquid handling of the measurement system as well as low-cost analytical alternatives including small-footprint FT-NIR meters, grating based and discrete wavelength spectrophotometers. Accordingly, we propose developing and implementing a multiplexed low-cost optical system for the quantification of key parameters that allows for in-line control of grape wine fermentations under practical conditions. The project will be driven by the expertise of HES-ARC with optical hardware and the establishment of calibration models, and the know-how of HES-CHANGINS with regards to fermentations and automation technology. Given the opportunities for both optical equipment and process automation manufacturers in Switzerland, as well as for the improvement of wine quality from application of modern vinification methods, we are convinced that the current project has a high potential for success, and future funding by public-private partnerships.

Research team within HES-SO: Salvadé Yves , Bussy Gaëtan , Jaccard Yvan , Bergerat Sylvain , Luthi Rowan , Amstutz Mathieu , Cléroux Marilyn , Mira De Orduña Heidinger Ramón , Llera Miguel , Pernet Arnaud

Partenaires académiques: 425 - Oenologie; Metrologie Qualité; Mira De Orduña Heidinger Ramón, 425 - Oenologie

Durée du projet: 01.10.2015 - 31.12.2017

Montant global du projet: 119'900 CHF

Statut: Completed

Développement d'un outil de diagnostic rapide pour l'évaluation de la composition et de l'efficacité de produits dérivés de levures inactivées

AGP

Role: Collaborator

Requérant(e)s: 425 - Oenologie, Mira De Orduña Heidinger Ramón, 425 - Oenologie

Financement: HES-SO Rectorat

Description du projet : The yearly global production of yeast extracts is estimated at 200'000 tons valued at over 500 million CHF. Yeast extracts are essential as food, food ingredients, and as nutrients used in traditional and modern industrial bioprocesses. In the dairy and wine industry, yeast extracts are the basis of starter propagation media or are used in the production itself. The added value of goods involving yeast extracts as additives or ingredients represents a multi-billion figure. Because of variable feedstocks used in the production of yeast extracts, as well as variations in processing and storage of the resulting biomass, the quality of yeast extracts is highly heterogeneous. A recent study published by the applicant demonstrates large compositional (elements, amino acids, vitamins, etc.) differences among commercial yeast extracts. This heterogeneity, including lot-to-lot variations, lead to poor bioprocess predictability and even contribute to production failures. Tables with average values for yeast extracts composition exist, but lot analyses are typically limited to few parameters only. Because of these issues, processors may resort to multiple-brand or -lot mixing, or complement yeast extracts with expensive components posing additional costs or legal issues. A multidisciplinary research consortium (HES-SO Valais, HES-Changins and Agroscope) with expertise in chemical analysis, process microbiology and microbial nutrition has been formed. Through the involvement of Agroscope, the project benefits from significant external support. It is proposed to: ' chemically characterize commercial yeast extracts (used as microbial nutrients in enology or medium ingredients in starter bacteria propagation for the dairy industry) for key compositional parameters including total protein, free amino acids, vitamins and minerals ' conduct massive parallel fermentations in microbioreactors that allow assessing the influence of yeast extracts on growth performance of selected reference organisms ' establish calibration models by FT-IR spectroscopy for the rapid prediction of chemical composition and bioassay performance or out-of-specification analysis. This study will provide compositional information as well as a novel FT-IR based rapid diagnostic tool for the assessment of yeast extracts. The outcomes will allow the wine, dairy and related industries to improve bioprocess predictability and efficiency. Because of the significant industrial and economical relevance, it is expected that private public partnerships will result from this project.

Research team within HES-SO: Pott Julien , Zinn Manfred , Cléroux Marilyn , Mira De Orduña Heidinger Ramón , Pernet Arnaud , Silvestri Anne-Claire

Partenaires académiques: 425 - Oenologie; VS - Institut Technologies du vivant; Mira De Orduña Heidinger Ramón, 425 - Oenologie

Durée du projet: 13.09.2015 - 12.09.2017

Montant global du projet: 150'000 CHF

Statut: Completed

2023

Development of distillation sensors for spirit beverages production monitoring based on impedance spectroscopy measurement and partial least-squares regression

Scientific paper ArODES

Liming Zeng, Arnaud Pernet, Marilyn Cléroux, Benoît Bach, Lucas Froidevaux, Ioana Preda

ACS Omega, 2023, 8, 17, 15323-15333

Link to the publication

Summary:

During spirit beverages production, the distillate is divided into three parts: the head, the heart, and the tail. Acetaldehyde and ethanol are two key markers which allow the correct separation of distillate. Being toxic, the elimination of the head part, which contains a high concentration of acetaldehyde, is crucial to guarantee the consumer’s health and security. Plus, the tail should be separated from the heart based on ethanol concentration. Nowadays, online or in-line sensors for acetaldehyde monitoring during distillation do not exist, and the online sensors for alcohol monitoring, based on density measurement, remain expensive for producers. In this work, we demonstrate the development of distillation monitoring sensors based on electrical impedance spectroscopy (EIS) measurements, combined with PLS-R (partial least-squares regression) modeling. Four types of sensors are proposed and tested with wine-based distillates. Using PLS-R, the best correlations were found for one electrode, named “SpotsSym”. With an R2 up to 89.9% for acetaldehyde concentration prediction and an R2 up to 86.8% for ethanol, the obtained results indicate the promising potential of the proposed approach. To our knowledge, this is the first report of sensors capable of simultaneously measuring ethanol and acetaldehyde concentrations. Furthermore, these sensors offer the advantages of being low cost and nondestructive. Based on these results, the development of an in-line distillation monitoring system is possible in the near future, providing a promising tool for spirit beverages producers.

2019

Automatization of membrane contactors and applications for the management of dissolved gases in wines

Scientific paper

Schönenberger Patrik, Ducruet Julien, Pernet Arnaud, Bach Benoit, Passeraub Philippe, Fanie Marsan, Denis Zufferey, Vorlet Olivier

BIO Web of Conferences ; Proceedings of 42nd World Congress of Vine and Wine, 15-19 July 2019, Geneva, Switzerland, 2019 , vol. 2019, vol. 15, article no 02037

Link to the publication

Summary:

Over the last decade, several distinct research groups tested possible uses of membrane contactors for the wine industry, notably for the management of dissolved gases in wines, adjustment of the O2 concentration while reducing the O2 concentration at the same time. Other experiments were done with partial alcohol reduction and addition of N2 to wines. The contactor’s heart is its Liqui-Cel™ membrane where the two separate circuits meet. The membrane’s hydrophobic characteristics allows a liquid to get in contact with a gas, without dispersing into it. The directions that these gases take through the membrane depend on their partial pressure differences within the two circuits. However, other factors need to be considered to determine exact exchange rates for each target gas. The present article describes the new membrane contactor prototype that was co-developed by the University of applied Sciences and Arts, Viticulture and Enology at Changins, Switzerland, and the School of Engineering and Architecture at Fribourg, Switzerland. The prototype was designed for small scale operations. Flow rates, temperatures and internal pressures can be instantly measured and graphically visualized. Also, O2 concentrations are measured inside the liquid. CO2 concentrations in the liquid can be measured with a device that is connected to the liquid circuit through a bypass after the membranes.

2018

Metabolism of Schizosaccharomyces pombe under reduced osmotic stress conditions afforded by fed-batch alcoholic fermentation of white grape must

Scientific paper ArODES

Gemma Roca-Domenech, Ricardo Cordero-Otero, Nicolas Rozès, Marilyn Cléroux, Arnaud Pernet, Ramón Mira de Orduña Heidinger

Food Research International,

Link to the publication

Summary:

Strains of Schizosaccharomyces pombe are being increasingly investigated with regards to their grape winemaking potential either in combination with the typical production yeast, Saccharomyces cerevisiae, or in monoseptic fermentations. Their ethanol tolerance and ability to degrade L-malic acid is oenologically convenient but contrasts with the comparatively high acetic acid and acetaldehyde formation potential which is considered undesirable, especially in white winemaking. The purpose of this work was to investigate the performance of a selected S. pombe strain in monoseptic femerntations of white grape must. Traditional batch fermentations were compared with an innovative and automated fed-batch fermentation technique were sugar concentrations are kept low during fermentations to decrease sugar induced osmotic stress. Because of its known effect on growth and ethanol tolerance, the effect of Mg was also tested. While Mg supplementation was not shown to significantly influence residual values of sugars, ethanol, glycerol, organic acids and acetaldehyde, the application of the fed-batch technique led to a fundamental change in yeast physiology. While glycerol values were only slightly reduced, the fed-batch approach allowed obtaining wines devoid of acetic acid whose levels were considerable in wines produced by the traditional batch technique (0.6 g/L). The work demonstrates that the acetic acid metabolism of S. pombe is associated to sugar induced osmotic stress such as for S. cerevisiae, too, and may be controlled by application of suitable fermentation techniques for winemaking.

2015

Effet des levures et des paramètres de vinification sur la dynamique des concentrations en acétaldéhyde

Scientific paper ArODES

Marilyn Cléroux, Arnaud Pernet, Ramon Mira de Orduña Heidinger, Anik Riedo, Muriel Mertenat, Nick Jackowetz, Erhu Li

Revue suisse Viticulture, Arboriculture, Horticulture, 47, 2015, 4, 232-237

Link to the publication

Summary:

Acetaldehyde is the main causative of combined SO2 in red and especially in white wines where it is responsible for 75 % of the bound SO2 on average. In wines that have not been aerated voluntarily (e.g. during pump-overs) or involuntarily, the major part of acetaldehyde stems from yeast metabolism. Within the major objective of reducing bound, and hence, total SO2 levels in wines, this project studied vinification factors that could influence yeast acetaldehyde production. The potential of various Saccharomyces and non-Saccharomyces strains to form acetaldehyde was also considered. The results show that yeast excrete acetaldehyde at the beginning of fermentations and reutilise a certain part of it afterwards. Residual acetaldehyde concentrations hence depend on the maximum reached as well as the extent of the reutilisation. Must sulphite addition was the largest contributor for maximum and residual acetaldehyde levels. On average, for every 10 mg/l of SO2 added to the must, the bound-SO2 concentration caused by acetaldehyde increased by 3–7 mg/l in white wines. The fermentation temperature affected the ability of yeast to reutilise acetaldehyde. Low fermentation temperatures correlated with high acetaldehyde residues. Some non-Saccharomyces strains produce considerably less acetaldehyde as S. cerevisiae strains. This characteristic could be confirmed with a commercial Torulaspora delbrueckii strain in a Chardonnay fermentation.

Dosage en continu des sucres et de l'alcool pendant les fermentations par spectroscopie proche infrarouge :

Professional paper ArODES

une opportunité pour l'automatisation des vinifications et les défis oenologiques actuels

Arnaud Pernet, Ramon Mira de Orduña Heidinger, Danielle Widmer, Anik Riedo, Muriel Mertenat, Marilyn Cléroux, Jean-Pascal Bourgeois, Olivier Vorlet, Charles Frohman

Revue suisse Viticulture, Arboriculture, Horticulture, 2015, vol. 47, no. 3, pp. 192-197

Link to the publication

Summary:

La spectroscopie infrarouge à transformée de Fourier (IRTF) est fréquemment utilisée pour l’analyse d’échantillons oenologiques en laboratoire. Le but de ce projet était de développer et valider une méthode d’IRTF permettant le dosage automatique des sucres et de l’éthanol en continu, c’est-à-dire directement dans la cuve de fermentation. Pour cela, une sonde de transflectance submersible a été reliée à un spectromètre IRTF proche infrarouge. Des modèles de calibration pour le glucose, le fructose, les sucres totaux (définis comme glucose + fructose) et l’éthanol ont été développés avec des échantillons d’apprentissage issus de plusieurs fermentations en blanc et en rouge. Une fois validés, ces modèles se sont avérés efficaces pour le dosage en continu des sucres totaux et de l’éthanol pendant les fermentations en conditions de turbidité pratiques, rapprochant ainsi le laboratoire de la cave. La méthode de dosage en ligne permet aussi de réaliser des fermentations fed-batch pour réduire le stress des levures et la production de métabolites secondaires tels que l’acide acétique. Son application sera évaluée pour la fermentation de moûts chargés en acide acétique.

2022

Low-cost impedance analyzer and IDC sensors :

Conference ArODES

an imperfect tool for dielectric condition monitoring

Ioana Preda, M. Colautti, Arnaud Pernet, Liming Zeng

2022 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 30 October- 2 November 2022, Denver, CO, USA

Link to the conference

Summary:

Low voltage (LV) cables, like medium or high voltage ones, are prone to ageing. However, as they are usually exposed to lower electrical stresses, they are seldom monitored. In this work, an IDC (Inter-Digital Capacitive) sensor combined with two different commercial impedance analyzers (Hioki IM3570 and AD5940) is evaluated. The sensitivity and the penetration of the electric field are calculated using Comsol Multiphyisics simulations and measurements performed on low voltage PVC cables help comparing the two systems and assessing their performance. It was found that, for low capacitive samples, such as a LV cable’s insulation, the variation found between consecutive measurements is too important to consider the AD5940 as a reliable tool for dielectric condition monitoring.

2019

Automatization of membrane contactors and applications for the management of dissolved gases in wines

Conference ArODES

Patrick Schönenberger, Julien Ducruet, Arnaud Pernet, Benoît Bach, Fanie Marsan, Philippe Passeraub, Denis Zufferey, Olivier Vorlet

BIO Web of Conferences ; Proceedings of 42nd World Congress of Vine and Wine, 15-19 July 2019, Geneva, Switzerland

Link to the conference

Summary:

Achievements

PEOPLE@HES-SO Directory and Skills inventory

Pernet Arnaud

Collaborateur technique en Ra&D

Collaborateur technique en Ra&D

PEOPLE@HES-SO
Directory and Skills inventory