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Le Touquet – Paris-Plage, France

Brochard M.,Institute Of Lelevage | Brochard M.,French National Institute for Agricultural Research | Brochard M.,Agro ParisTech | Duhem K.,Institute Of Lelevage | And 4 more authors.
Productions Animales | Year: 2014

Thanks to PhenoFinlait program many knowledge and applications were developed regarding fine milk composition analysis, links between milk composition and farming systems, genetic determinism of milk fatty acids and proteins. Those results are based on a large scale data collection covering about 1,500 commercial farms. French dairy cattle, sheep and goat industries have now access to estimation equations for fatty acids and proteins based on mid infra-red spectra (MIR); very precise qualitative and quantitative analyzing method for milk proteins; references and tools to control milk composition by monitoring dairy females and animal feeding; reference populations for genomic selection and knowledge on genetic determinism of milk fatty acids and proteins profiles. Moreover, thanks to PhenoFinlait program, French research and dairy industries get a huge experience on MIR spectral data; large data-base and sample banks (milk and DNA) available for new developments both to go further on fine milk composition, or to investigate new topics (milk production traceability, animal health and reproduction monitoring, enteric methane emission...). Appropriation and valorization by the different French dairy industries stakeholders is going on, but a lot of work and efforts still has to be done for accompanying field actors in relevant implementation improving competitiveness of their process. Besides, many new research projects come directly from PhenoFinlait program or are partially based on its data, samples and know-how. It is very likely that it will generate new knowledge, references and applications of interest for French researchers, farmers and dairy industries. Source

Velly H.,Cniel | Velly H.,French National Institute for Agricultural Research | Velly H.,Agro ParisTech | Bouix M.,French National Institute for Agricultural Research | And 12 more authors.
Applied Microbiology and Biotechnology | Year: 2014

This work aimed at characterizing the biochemical and biophysical properties of the membrane of Lactococcus lactis TOMSC161 cells during fermentation at different temperatures, in relation to their freeze-drying and storage resistance. Cells were cultivated at two different temperatures (22 and 30 °C) and were harvested at different growth phases (from the middle exponential phase to the late stationary phase). Bacterial membranes were characterized by determining the fatty acid composition, the lipid phase transition, and the membrane fluidity. Cultivability and acidification activity losses of L. lactis were quantified after freezing, drying, and 3 months of storage. The direct measurement of membrane fluidity by fluorescence anisotropy was linked to lipid composition, and it was established that the cyclopropanation of unsaturated fatty acids with concomitant membrane rigidification during growth led to an increase in the freeze-drying and storage resistance of L. lactis. As expected, cultivating cells at a lower fermentation temperature than the optimum growth temperature induced a homeoviscous adaptation that was demonstrated by a lowered lipid phase transition temperature but that was not related to any improvement in freeze-drying resistance. L. lactis TOMSC161 was therefore able to develop a combined biochemical and biophysical response at the membrane level during fermentation. The ratio of cyclic fatty acids to unsaturated fatty acids (CFA/UFA) appeared to be the most relevant parameter associated with membrane rigidification and cell resistance to freeze-drying and storage. This study increased our knowledge about the physiological mechanisms that explain the resistance of lactic acid bacteria (LAB) to freeze-drying and storage stresses and demonstrated the relevance of complementary methods of membrane characterization. © 2014, Springer-Verlag Berlin Heidelberg. Source

Burgain J.,Cniel | Burgain J.,CNRS Biomolecular Engineering Laboratory | Scher J.,CNRS Biomolecular Engineering Laboratory | Petit J.,CNRS Biomolecular Engineering Laboratory | And 3 more authors.
Food Hydrocolloids | Year: 2016

Storage is an unavoidable critical phase regarding dairy powder reconstitution abilities, particularly for high casein content powders, which generally present a poor rehydration behavior. The ability of micellar casein powders to completely rehydrate can thus be particularly affected by storage time and temperature. To implement best practices for the optimization of storage conditions, understanding changes occurring is a crucial point. For the first time, biophysical techniques were used to investigate powder surface at the nanoscale. Atomic force microscopy revealed that particle surface became rougher during storage, associated with the formation of hollow zones (around 500 nm) holes when stored for 10 months at 40 °C. Mechanical properties of micellar casein particle surface during powder storage was quantified using AFM nanoindentation. Spatially-resolved force/indentation curves evidenced a significant stiffer surface for aged powder (Young modulus of ~20 GPa) in comparison with the fresh one (~0.2 GPa). These findings were fully consistent with the formation of a crust at the powder surface observed by high-resolution field-emission scanning electron microscopy during powder rehydration. Finally, alterations of the rehydration process can be related to modifications occurring at the particle surface during storage. © 2016 Elsevier Ltd. Source

Burgain J.,Cniel | Burgain J.,CNRS Biomolecular Engineering Laboratory | El Zein R.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment | Scher J.,CNRS Biomolecular Engineering Laboratory | And 5 more authors.
Journal of Food Engineering | Year: 2016

Dairy powders are stable ingredients that are frequently stored prior to use. In fact, during powder manufacture, precautionary measures are taken to ensure optimal technological and nutritional functionalities, but during storage, changes in physico-chemical and functional properties of whey protein isolate (WPI) powders were extensively outlined. In the present study, WPI powders were stored at 60°C and 0.2 water activity for one month and local modifications on particle surface were explored. Atomic force microscopy (AFM), specifically in chemical force microscopy (CFM) mode, was used to follow surface modifications during storage. An increase in surface hydrophobicity was noticed when powders were stored at high temperatures. Complementary techniques such as microscopy and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) showed a crackled surface and a decrease in the presence of amino acid at surface. Finally, powder browning and fluorescence of components on particle surface suggested that Maillard reaction is the main phenomenon responsible for powder alteration during storage. © 2016 Elsevier Ltd. All rights reserved. Source

Michalski M.C.,INSA Lyon | Genot C.,French National Institute for Agricultural Research | Gayet C.,Cniel | Lopez C.,Agrocampus Ouest | And 7 more authors.
Progress in Lipid Research | Year: 2013

On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen. © 2013 Elsevier Ltd. All rights reserved. Source

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