Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal

Home page

PhD defense of Norman Wiernascz

2 avril 2019 - Oniris, Site de la Chantrerie

PhD defense of Norman Wiernascz
On the topic: Seafood quality and safety improvement through hurdle technology, including biopreservation. Impact on microbial ecosystems.

PhD thesis:

Supervised by Marie-France Pilet (SECALIM) and co-supervised by Françoise Leroi (IFREMER)

As part of the European project SAFEFISH DISH

Abstract:

Seafood products count for an important part of our diet. However, they are fragile and have a limited shelf-life due to microbial spoilage. The objective of this thesis was to develop a biopreservation strategy applied to a salmon-based product, the gravlax, in order to improve its microbiological quality and safety. We firstly characterized this poorly known product on a microbiological (cultural analysis and metabarcoding of the 16S rRNA encoding gene), physico-chemical (biogenic amines and volatile organic compounds...) and sensorial point of view. Compared to smoked salmon packed under vacuum or modified atmosphere, the gravlax shows a higher microbial diversity, dominated by enterobacteria and linked to a specific volatilome and sensory profile. In a second time, six lactic acid bacteria strains were selected on technological criteria such as antimicrobial activity, spoilage potential, tolerance to freezing and chitosan, as well as safety criteria such as biogenic amines production and antibiotic resistance. These 6 strains were then applied on gravlax to evaluate their bioprotective potential. They are distinguished by their implantation capacity and their impact on the product microbial ecosystem, volatilome and sensory properties. A strain of Vagococcus fluvialis and Carnobacterium maltaromaticum were able respectively to control the sensorial spoilage and to inhibit Listeria monocytogenes, during gravlax refrigerated storage.

Keywords:

biopreservation, metabarcoding, microbial ecosystem, volatilome, sensory analysis, gravlax

Examiners:

Lisbeth Truelstrup Hansen (DTU, Denmark)

Luca Cocolin (UNITO, Italy)

Stéphane Chailloux (Micalis, INRA France)

Jean-Michel Cappelier (SECALIM)