1.5 h teaching course: Effects of extrusion-cooking process on structure and technological properties of protein rich food

Purpose: The course is provided to technicians and to process engineers working on the cooking-extrusion process.
The purpose is to show the effects of cooking-extrusion process on high protein foods, to explain physicochemical phenomena occurring during the transformation process and leading to new food texture products. After a general introduction on proteins (structures, bounds, technological abilities and denaturation), the course has an important section concerning the physical chemistry of specific food proteins, such as gluten, muscle, egg, milk and whey proteins. The effects of physicochemical environment modification by pH or ionic strength changing and/or application of temperature or of shear force are explained.
The last section concerns the application of the process to high protein food content, how several ingredients interact each other to produce textured food and new microstructures, providing some practical examples.

Title: Microstructure of extruded cereal products studied by neutron tomography

Neutron tomography is a 3D imaging technique permitting to observe large objects (size of several centimetres) at the resolution of several microns. The technique is based on the interaction of neutrons with the matter and, in biological matter, neutrons scattering happens due to the presence of hydrogen atoms that offers the highest contrast in radiographies.
This technique allows microstructure characterisation of extruded cereal products. Image analysis is realised by studying the impact of formula (different water content) and storage conditions (different relative humidity) on extruded cereal microstructure, in terms of skeleton (length, thickness and volume) and of porosity (pore size distribution). Tutorials concerning the use of reconstruction (Octopus) and analysis (AVIZO) software are realised.

Title: Collaboration in the development of neutron imaging station prototype, IMAGINE: the case of meat cooking

The Laboratoire Léon Brillouin (CEA Saclay), French national source of neutrons, built an imaging station in order to permit matter exploration at microscopic scale. The advantage of neutron imaging is the use of particular and complex sample environment because neutrons can pass through some materials, like metals.
Within this project, I contributed to the development of the imaging station by my scientific case: meat cooking. The aim was to evaluate the changes occurring in meat during the process (morphology and water migration) at the scale of fibres, by studying attenuation coefficient evolution. Several experiences were realised to develop the imaging station, IMAGINE: from “offline” measures taking sample images before and after cooking process, to meat evolution following during the process in an oven. In the latter case, the oven was placed on the neutron beam and equipped with an optical fibre to follow the evolution at microscopic and molecular scales at the same time. Some macros on the MatLab were realised to process dynamic image sequences.
Moreover, neutron tomography can be performed on IMAGINE to characterise 3D objects. In the case of meat, 3D images permitted to show fibre contraction and matter densification, by different contrast zones.

During my doctorate, I realised a trainee at the Oak Ridge National Laboratory, thanks to the mobility scholarship of Doctoral School Environnement-Santé that I obtained. As visiting researcher, I worked on neutron image processing of meat samples, obtained during cooking process and realised on the imaging station IMAGINE at the Laboratoire Léon Brillouin (CEA Saclay). I had the opportunity to work with experts of neutron imaging, Dr. Hassina Bilheux e Dr. Jean‑Christophe Bilheux.

April 2015, (Invited) 3 h teaching course: Opticook Project: Towards Smart Cooking Processes
Bordeaux Sciences Agro, Nutrition-Health and Agricultural Sector Department

Purpose: showing to 2nd-year students an alternative professional career: fundamental and applied research on meat, a product of agricultural sector.
Oral presentation of my Ph.D project: Open Food System-Opticook project and temperature impact on muscle biochemistry: studies at molecular and microscopic scales by spectroscopies and neutron imaging.

Sep. 2014 – Dec. 2014, 50 h Practical Work: Food Technology, Unit Operation, Module I: Heat Transfer
IUT Dijon, Biological Engineering Department, Specialisation in Food Processing Industry

Purpose: Description and explanation of heat transfer manufacturing process used in the food industry in order to transform and stabilise food (steam generator, heat exchanger, plate heat exchanger, tunnel dryer, spray-dryer, conventional and microwave oven cooking and cooling down liquid by refrigerated tank). Students had to set up process and to answer to questions using data from the engine system/machine. I was responsible for their training on steam generator and spray-dryer machines.

Supplier management: forms checking and filing; computerisation of qualification procedure; purchased products and non-conformities management schedule and analysis.
Purchase check procedures: documents, labels and test reports.
Shelf-life control plan of “Dal Mare” private label.
Naturland Certification.
Organisation of food handler training course

Back office organisation and restaurant preparation.
Service to customers’ table.

Week-end job.
Welcome to customers and service.
Catering and banqueting service for specific events (weeding).

Master's Level Project
Title: Structural impact of pre-heating treatments on whey proteins: biophysical studies from macroscopic to molecular scale.

The project was realised within the physical-chemistry team, EMMA (AgroSup Dijon, France). It concerns whey powders coming from cheese manufacture and considered as by-products. Whey is an important ingredient in food formulation, due to its technological properties. Texture, emulsion and foam stabilization properties strongly depend on its production processing (drying and physico-chemistry conditions). The process has to be set up in such a way to have the least impact on whey proteins structure. The work is carried out especially on β-Lactoglobulin, the most abundant whey protein, which is purified from the whole whey powder. The protein denaturation is studied at several temperatures conditions and close to its denaturation peak, in order to study wide range. Several biophysical equipment/methods are used characterizing overall and local protein structure (calorimetry, dynamic light scattering, fluorescence spectroscopy) as well as chemical assay (the specific Ellman’s assay for thiol groups).

Keywords: Whey proteins, β-lactoglobulin, calorimetry, dynamic light scattering, thiol group accessibility.

Bachelor’s Level Project
Title: Benefit evaluation on fresh cheese produced by innovative packaging system (active packaging).

This project was a collaboration between the University of Udine (Italy) and two local companies: Arcadia (food packaging producer) and Latteria Montello (dairy food producer). The aim is to delve into knowledge of flexible (film) active packaging, in which the active principle is one of ingredients of the film. This kind of packaging allows action of the active ingredient by contact on the whole food surface. The impact of the active packaging is investigated (and compared with traditional packaging) on fresh cheese, observing evolution of microbial flora, texture and sensorial profile during the shelf-life.

Keyword: active packaging, OVTENE, food packaging, dairy products

Summer seasonal job.
Organisation and management of bar service and foodstuff flow: barman chief assistance.