University of Avignon

About: University of Avignon is a education organization based out in Avignon, Provence-Alpes-Côte-d'Azur, France. It is known for research contribution in the topics: Population & Speaker recognition. The organization has 1526 authors who have published 3766 publications receiving 88928 citations.

Bio-Based Solvents for Green Extraction of Lipids from Oleaginous Yeast Biomass for Sustainable Aviation Biofuel.

Abstract: Lipid-based oleaginous microorganisms are potential candidates and resources for the sustainable production of biofuels. This study was designed to evaluate the performance of several alternative bio-based solvents for extracting lipids from yeasts. We used experimental design and simulation with Hansen solubility simulations and the conductor-like screening model for realistic solvation (COSMO-RS) to simulate the solubilization of lipids in each of these solvents. Lipid extracts were analyzed by high performance thin-layer chromatography (HPTLC) to obtain the distribution of lipids classes and gas chromatography coupled with a flame ionization detector (GC/FID) to obtain fatty acid profiles. Our aim was to correlate simulation with experimentation for extraction and solvation of lipids with bio-based solvents in order to make a preliminary evaluation for the replacement of hexane to extract lipids from microorganisms. Differences between theory and practice were noted for several solvents, such as CPME, MeTHF and ethyl acetate, which appeared to be good candidates to replace hexane.

Degradation of Edible Oil during Food Processing by Ultrasound: Electron Paramagnetic Resonance, Physicochemical, and Sensory Appreciation

Abstract: During ultrasound processing of lipid-containing food, some off-flavors can be detected, which can incite depreciation by consumers. The impacts of ultrasound treatment on sunflower oil using two different ultrasound horns (titanium and pyrex) were evaluated. An electron paramagnetic resonance study was performed to identify and quantify the formed radicals, along with the assessment of classical physicochemical parameters such as peroxide value, acid value, anisidine value, conjugated dienes, polar compounds, water content, polymer quantification, fatty acid composition, and volatiles profile. The study shows an increase of formed radicals in sonicated oils, as well as the modification of physicochemical parameters evidencing an oxidation of treated oils.

Guessing Revisited: A Large Deviations Approach

Abstract: The problem of guessing a random string is revisited. A close relation between guessing and compression is first established. Then it is shown that if the sequence of distributions of the information spectrum satisfies the large deviation property with a certain rate function, then the limiting guessing exponent exists and is a scalar multiple of the Legendre-Fenchel dual of the rate function. Other sufficient conditions related to certain continuity properties of the information spectrum are briefly discussed. This approach highlights the importance of the information spectrum in determining the limiting guessing exponent. All known prior results are then re-derived as example applications of our unifying approach.

Interactions between cell wall polysaccharides and polyphenols: Effect of molecular internal structure.

Abstract: Cell wall polysaccharides (CPSs) and polyphenols are major constituents of the dietary fiber complex in plant-based foods. Their digestion (by gut microbiota) and bioefficacy depend not only on their structure and quantity, but also on their intermolecular interactions. The composition and structure of these compounds vary with their dietary source (i.e., fruit or vegetable of origin) and can be further modified by food processing. Various components and structures of CPSs and polyphenols have been observed to demonstrate common and characteristic behaviors during interactions. However, at a fundamental level, the mechanisms that ultimately drive these interactions are still not fully understood. This review summarizes the current state of knowledge on the internal factors that influence CPS-polyphenol interactions, describes the different ways in which these interactions can be mediated by molecular composition or structure, and introduces the main methods for the analysis of these interactions, as well as the mechanisms involved. Furthermore, a comprehensive overview is provided of recent key findings in the area of CPS-polyphenol interactions. It is becoming clear that these interactions are shaped by a multitude of factors, the most important of which are the physicochemical properties of the partners: their morphology (surface area and porosity/pore shape), chemical composition (sugar ratio, solubility, and non-sugar components), and molecular architecture (molecular weight, degree of esterification, functional groups, and conformation). An improved understanding of the molecular mechanisms that drive interactions between CPSs and polyphenols may allow us to better establish a bridge between food processing and the bioavailability of colonic fermentation products from CPSs and antioxidant polyphenols, which could ultimately lead to the development of new guidelines for the design of healthier and more nutritious foods.