Characterization of hydroxytyrosol-β-cyclodextrin complexes in solution and in the solid state, a potential bioactive ingredient

This study focused for the first time on characterizing the inclusion complexes between β-cyclodextrin (β-CD) and hydroxytyrosol (HT) in the solid state. In solution, HT and β-CD are able to form a 1:1 inclusion complex with an association constant of 33.2 ± 3.7 M-1. In the solid state, the inclusion complexes prepared by freeze-drying and spray-drying of an equimolar mixture of both partners were characterized and compared by 13C NMR and SEM. After dissolution, their free radical-scavenging ability was also determined by UV–visible spectroscopy. The results show that β-CD and drying processes have no effect on the efficiency of HT to reduce the DPPH radical. The solid state 13C NMR data provided information on the spatial proximity between β-CD and HT and suggest the formation of inclusion complexes for both drying processes compared to the physical mix. However, the morphology of the solids obtained was significantly different, as spherical particles were formed by spray-drying while freeze-drying only provided irregular shapes

Application de la détente instantanée contrôlée pour l'eco-extraction des produits naturels (intensification & combinaison)

Cette étude porte sur l analyse fondamentale et expérimentale des processus d extraction des procédés conventionnels et innovants. L intensification de ces techniques s est tout d abord basée sur des approches théoriques. D une part, nous nous sommes focalisés sur le paradoxe généré par l extraction conventionnelle des huiles essentielles et les issues et solutions que la Détente Instantanée Contrôlée (DIC) ou les Micro-Ondes (MO) peuvent apporter. D autre part, nous nous sommes intéressés à la problématique d intensification des opérations d extraction par solvant des composés non-volatils à partir de végétaux. La spécificité des processus diffusionnels leur donne une importance particulière en raison de la structure propre de la matière, traduisant ainsi une mauvaise aptitude technologique intrinsèque. L amélioration de l extraction par l action de la DIC sur la structure de la matrice, des MO sur le chauffage et des UltraSons (US) sur la micro-agitation, permet d envisager un couplage, de conduire à une intensification après optimisation souvent multicritères (cinétique, qualité et énergie). La DIC a été appliquée sur des feuilles de romarin et des écorces d orange afin d en extraire les huiles essentielles. Ce traitement a permis d accéder à une expansion et de parvenir à une intensification de l extraction des molécules antioxydantes. Nous avons donc procédé à une combinaison DIC/MO pour le romarin et DIC/US pour les écorces d orange. Enfin, la cinétique de l extraction d huiles de colza a été intensifiée par un prétraitement DIC et étudiée à travers une modélisation dont l un des aspects a été une diffusion de type Fick couplée à une solution de CrankThis study focuses on fundamental analysis and experimental work carried out on extraction via conventional and innovative processes. The intensification of these techniques is first based on theoretical approaches. On the one hand, we focused our meditation on examining the "paradox" generated by conventional steam-distillation of essential oils, and suggested solutions from Instant Controlled Pressure Drop (DIC) or Microwave (MW). On the other hand, we were interested in the problematic of solvent extraction operations of plant-based non-volatile compounds. The specificity of the diffusional process gives them a special importance because of the specific structure of the material, reflecting poor intrinsic technological ability. Improving extraction by letting DIC act on the structure of the matrix, MW on heating, and UltraSound (US) on the micro-agitation, allows to coupling technologies leading to a perfect intensification and thus multi-criteria optimization (kinetics, quality and energy). DIC was applied to the leaves of rosemary and orange peel to extract essential oils. This treatment has access to expansion and to achieve increased extraction of antioxidant molecules. We therefore conducted a combination DIC/MW for rosemary and DIC/US for orange peel. Finally, the extraction kinetics of rapeseed oil has been intensified by DIC pretreatment. This kinetics was identified through modeling including Fick diffusion coupled to a Crank solutionAVIGNON-Bib. numérique (840079901) / SudocSudocFranceF

Enrichissement nutritionnel de l huile d olive (entre tradition et innovation)

L huile d olive est un produit ancestral largement reconnu pour ses effets bénéfiques sur la santé humaine. Sa technique de fabrication a beaucoup évolué au cours des siècles, notamment ces dernières années avec l automatisation croissante des chaînes de production. La première partie de ce manuscrit fait le bilan de ces différentes évolutions, puis la seconde partie détaille l impact de chacune des étapes de fabrication sur la composition nutritionnelle de l huile. Nous avons ainsi étudié l influence du broyage, des séparations liquide-liquide et solide-liquide. L optimisation de ces étapes permet l obtention d une huile enrichit de façon endogène puisque tous les nutriments étaient présents dans l olive. En complément nous avons également développé des méthodes d enrichissement exogène de l huile. Dans ce cas des molécules bioactives issues de plantes ou de légumes sont ajoutées à l huile d olive. Afin de limiter les étapes d extraction et de bannir l utilisation de solvants organiques, l huile est utilisée en tant que solvant d extraction et l enrichissement se fait de façon directe dans l huile. Pour accélérer des cinétiques d extraction qui pourraient être très longues, nous avons utilisé des ultrasons. Les résultats obtenus sont très encourageants et ils permettent d imaginer un élargissement de la gamme de produits oléicoles disponiblesOlive oil is an ancestral product widely known for its benefic effects on human health. Its processing has changed a lot through centuries, especially these past few years with the increasing automation of the production lines. The first part of this manuscript describes these evolutions while the second part gives details on the influence of each processing step on the nutritional composition of the olive oil. We have studied the influence of the crushing systems, liquid-liquid and solid-liquid separations. The optimization of each of these steps allows the endogenous enrichment of the oil with nutrients extracted from the olive fruit. Then, we have also developed exogenous olive oil enrichment methods by bioactive compounds issued from plants and vegetables. In order to restrain the number of extraction steps and avoid the use of petroleum solvents, the olive oil is used as the extraction solvent so the enrichment is directly performed in the oil. To accelerate extraction kinetics that could be very long we developed ultrasound accelerated extraction techniques. The results obtained in this work are very promising and extensions of olive oil available product ranges are possibleAVIGNON-Bib. numérique (840079901) / SudocSudocFranceF

Soxhlet assisté par micro-ondes (conception et application à l'extraction des matières grasses)

De manière générale, la préparation d'échantillon peut être décomposée en deux étapes distinctes : extraction et analyse. Alors que l'étape analytique requiert quelques minutes, l'étape d'extraction nécessite plusieurs heures (ou jours). C'est le cas de la méthode de Soxhlet, inventée en 1879 qui est aujourd'hui la procédure de référence pour l'extraction solide-liquide. Depuis la découverte des effets thermiques des micro-ondes par Spencer en 1946, l'impact des micro-ondes sur la matière a été largement caractérisé et validé par la communauté scientifique. Rapidement, les micro-ondes ont été utilisées pour l'extraction dans le but de contrecarrer les limites des techniques d'extraction conventionnelles. Notre travail a consisté en la conception, l'optimisation et la valorisation d'une technique d'extraction destinée au dosage des matières grasses dans les matrices alimentaires solides : le Soxhlet assisté par micro-ondes. Une première partie du document est consacrée à la compréhension des fondements et considérations théoriques de l'énergie micro-ondes. Une seconde partie du manuscrit rappelle les techniques employées pour la conception et valorisation du Soxhlet assisté par micro-ondes. Enfin, la dernière partie du manuscrit traite des résultats obtenus et s'articule selon trois sections distinctes : dans un premier chapitre, la mise au point, l'optimisation et l'application du nouveau dispositif sont décrites. L'appareillage permet des extractions rapides, non destructrices et généralisables à diverses matrices alimentaires discutées dans un second chapitre. L'approche écologique de l'invention, combinée à l'emploi du d-limomène, comme alternative au n-hexane conventionnel, fait l'objet d'un troisième et dernier chapitreIn most cases, sample preparation can be divided in two distinctive steps : extraction and analysis. While analytical step requires few minutes, the extraction step requires several hours (or days). This applies to the Soxhlet method, invented in 1879, which today is the reference for solid-liquid extraction. Since the discovery of thermal effects of microwaves by Spencer in 1946, the impact of microwaves on the matter has been widely characterized and validated by the scientific community. Quickly, microwaves were used for extraction to counteract limitations of conventional extraction procedures. Our work consisted of design, optimization and development of a new extraction technique for the determination of fat in solid food samples : the microwave-integrated Soxhelt. The first part of the document is devoted to understanding the theoretical foundations and considerations of microwave energy. A second part of the manuscript refers to the techniques used for the design and optimization of microwave-integrated Soxhlet. Finally, the last part of the manuscript deals with the results obtained and is divided into three distint sections : in a first chapter, the development, optimization and implementation of the new device are described. The apparatus allows rapid and non-destructive extractions that can be generalized for various food matrices. This topic is discussed in a second chapter.The ecological approach of the invention, combined with the use d-limonene, as an alternative to conventional n-hexane, is the subjet of a third and final chapterAVIGNON-BU Centrale (840072102) / SudocSudocFranceF

Total Lipid Extraction of Food Using d-Limonene as an Alternative to n-Hexane

International audienc

The inclusion complex of rosmarinic acid into beta-cyclodextrin: A thermodynamic and structural analysis by NMR and capillary electrophoresis

International audienceThis work focuses on the characterization of the rosmarinic acid (RA)-b-cyclodextrin (CD) complex in aqueous solution by 1H NMR (1D- and 2D-ROESY), completed with studies by capillary electrophoresis (CE). From the 1H NMR data, the stoichiometry of the complex was determined by a Job’s plot and the binding constant was estimated from a linear regression (Scott’s method). At pH 2.9, the results showed that RA binds CD with a 1:1 stoichiometry and a binding constant Kb of 445 (±53) M-1 or 465 (±81) M-1 depending on the CD protons (H-5 or H-3) selected for the evaluation. The Kb value was also calculated from the CD-induced chemical shifts of each RA proton in order to collect information on the structure of the complex. The pH dependence of Kb revealed that the RA carboxylic form displays the highest affinity for CD. An investigation by capillary electrophoresis fully confirmed these results. 2D ROESY analysis provided detailed structural information on the complex and showed a strong correlation between H-3 and H-5 of CD and most RA protons. In conclusion, RA, an efficient phenolic antioxidant from rosemary with a marketing authorization, spontaneously forms a relatively stable inclusion complex with CD in water

Direct and Rapid Profiling of Biophenols in Olive Pomace by UHPLC-DAD-MS

A correction to this article is available online at https://doi.org/10.1007/s12161-017-1107-8.Olive mill by-products are effluents generated during olive oil production process. The two-phase centrifugation system produces a semi-solid olive pomace called “alperujo.” This by-product is a combination of liquid and solid wastes derived from the three-phase manufacturing process. A direct and fast analytical method by ultra-high-performance liquid chromatography-DAD coupled with ESI/MS-MS has been developed for the profiling of phenolic compounds. Thirty-five metabolites belonging to phenyl alcohols, secoiridoids, flavonoids, and iridoids were identified as the main constituents of alperujo in 12 min, including p-coumaroyl aldarate and a verbascoside derivative found for the first time in alperujo and a new ligstroside derivative. Six quantitatively significant components were determined at concentrations ranging from 17.7 mg/L for p-coumaric acid to 370.7 mg/L for hydroxytyrosol. Our data confirm that alperujo is an interesting source of phenolic compounds that could be extracted for use as nutraceuticals

New microwave-integrated Soxhlet extraction

International audienc