Discrimination by Infrared Spectroscopy: Application to Micronized Locust Bean and Guar Gums

The authentication of locust bean and guar powder gums requires usually the use of sophisticated and time-consuming analytical techniques. There is a need for fast and simple analytical techniques for the objective of a quality control methodology. Commercial locust bean and guar micronized powder gums present characteristic MIR spectra. Principal component analysis of the infrared spectra of these micronized powder gums allowed to distinguish locust bean from guar samples and to perform good classification results. The prediction of the two varieties was done without any ambiguity with a partial least square regression-discriminant analysis (PLS-DA). A simplex approach was used to generate binary blends mathematically taking into account the intrinsic variability of chemical composition of commercial products. The simulated spectral profiles allowed to develop predictive model of the percentage of gums in blends

Caractérisation physique (granulométrie, nature de la matrice minérale) de la formulation commerciale à 5% de chlordécone utilisée autrefois en bananeraie aux Antilles françaises et connue sous le nom de Curlone®

National audienceVery little information is available in the literature on Curlone®. An analysis of its chemical composition would be welcome, in order to know, for example, whether dechlorinated products detected in the French West Indies environment are truly the product of chlordecone (CLD) degradation processes or correspond to synthetic impurities accompanying it. Similarly, all epidemiological studies have focused on CLD alone, without considering possible toxicity synergisms due to the presence of impurities. To overcome this lack of information, in 2016 we were able to analyze the composition of 3 Curlone® samples, which revealed that no less than 23 organic compounds were present in the product in addition to CLD.In addition to the organic chemical composition of Curlone®, other parameters such as the size of the particles it contains, or the nature of the mineral material used to dilute the CLD, are sorely lacking among the experts tasked with assessing the exposure risk of the workers who applied the product, with a view to having it recognized as an occupational disease. As for the mineral content of Curlone®, several contradictory pieces of information are circulating. According to the former director of the Calliope group, which manufactured it, it was CaCO3 in the form of Durcal® (marble crushed stone) produced by the Omya company, but other sources suggest that it could be talc or kaolin.Granulometry measurements carried out on 6 samples of Curlone® obtained from independent bags indicate that this material was made up of small particles with an average size of between 42 and 56 µm, with 50% of particles even smaller than 14.6 µm and 10% smaller than 1.35 µm. With this granulometry, it is hardly surprising that, according to one witness, the 2-cartridge masks worn by the applicators clogged up within an hour of applying the product (Christian Chabrier, CIRAD researcher, personal communication). It should be noted that many of the people applying the product at the time did not have such protective equipment. According to the same source, Curlone® particles flew around the applicators, who ended up covered in white dust, which managed to get under their clothes. Our measurements and this testimonial therefore suggest that applicators were widely exposed by both inhalation and dermal routes.Infrared spectra of the same Curlone® samples were very similar, with small differences in intensity probably due to different water contents. The 3 peaks characteristic of CaCO3 were found at 1387, 870 and 712 cm-1 in each sample. However, characteristic kaolin peaks were also found at 3693, 3620, 1166, 1154, 1108, 1030, 1005, 793 and 752 cm-1. The main talc peaks, on the other hand, were absent at 963, 666, 546 and 506 cm-1. This result suggests that the mineral filler in Curlone® was a mixture of CaCO3 and kaolin.Très peu d’information est disponible dans la littérature sur la Curlone®. Une analyse de sa composition chimique serait pourtant bienvenue afin de savoir par exemple si des produits déchlorés détectés dans l’environnement antillais sont véritablement le fruit de processus de dégradation de la chlordécone (CLD) ou correspondent à des impuretés de synthèse l’accompagnant. De la même façon, toutes les études épidémiologiques se sont focalisées sur la seule CLD sans considérer les éventuels synergismes de toxicité dus à la présence d’impuretés. Afin de palier à ce manque d’information, en 2016, nous avons pu analyser la composition de 3 échantillons de Curlone® qui ont permis de mettre en évidence que pas moins de 23 composés organiques étaient présents dans le produit en plus de la CLD (Macarie et al., 2016).A côté de la composition chimique organique de la Curlone® d’autres paramètres comme la taille des particules qui la composent ou la nature du matériel minéral ayant été utilisé pour diluer la CLD manquent cruellement aux experts chargés d’évaluer à postériori le risque d’exposition des ouvriers qui appliquaient le produit en vue d’une reconnaissance de maladie professionnelle. Pour ce qui est de la charge minérale de la Curlone®, plusieurs informations contradictoires circulent. D’après l’ancien directeur du groupe Calliope qui la fabriquait, il s’agirait de CaCO3 sous forme de Durcal® (broyat de marbre) produit par la société Omya, mais d’autres sources suggèrent qu’il pourrait s’agir de talc ou de kaolin (Wales, 1962; Letchimy et Benin, 2019) Les mesures de granulométrie réalisées sur 6 échantillons de Curlone® provenant de sacs indépendants indiquent que ce matériel était constituée par de petites particules de taille moyenne comprise entre 42 et 56 µm, 50% des particules ayant même une taille inférieure à 14.6 µm et 10% à 1.35 µm. Avec cette granulométrie, il n’est donc pas étonnant que d’après un témoignage, les masques à 2 cartouches portés par les applicateurs se soient bouchés en moins d’une heure d’application du produit (Christian Chabrier, chercheur au CIRAD, communication personnelle). A noter que nombre de personnes qui l’appliquaient à l’époque ne disposaient pas d’un tel équipement de protection. D’après la même source, les particules de Curlone® volaient autour des applicateurs qui finissaient les chantiers couverts de poussière blanche, laquelle réussissaient à s’immiscer sous les vêtements. Nos mesures et ce témoignage suggèrent donc que les applicateurs étaient largement exposés par inhalation comme par voie cutanée.Les spectres infrarouges de ces mêmes échantillons de Curlone® se sont révélés très similaires avec de petites différences d’intensité probablement dues à des contenus en eau différents. Les 3 pics caractéristiques du CaCO3 ont été retrouvés à 1387, 870 et 712 cm-1 dans chacun des échantillons. Des pics caractéristiques du kaolin y ont toutefois aussi été retrouvés à 3693, 3620, 1166, 1154, 1108, 1030, 1005, 793 et 752 cm-1. Les principaux pics caractéristiques du talc étaient par contre absents à 963, 666, 546 et 506 cm-1. Ce résultat suggère que la charge minérale de la Curlone® correspondrait donc à un mélange de CaCO3 et de kaolin

NIR spectroscopy for the quality control of Moringa oleifera (Lam.) leaf powders: Prediction of minerals, protein and moisture contents

International audienc

AComDim highlighting of agroclimatic factors influencing the Moringa oleifera Lam. leaf’s composition

International audienceThe quality control of the chemical composition leaves of Moringa oleifera Lam. is fundamental for the dietary treatment of diseases or for any quantitative study on human nutrition. To highlight the impact of climatic and edaphic factors on the chemical composition of Moringa oleifera Lam. leaves, a multivariate chemometric method, ANOVA (ANalysis Of Variance) Common Dimensions (AComDim) was used to interpret the changes in their Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectra. Leaves were collected from five geographical areas of Cameroon, recognized for their climatic and soil diversity. The factor “agroclimatic zone” was the most significant, followed by “month/year” (January, April and September between 2015 and 2017), “year” and “maturity” factors. Three slightly significant interactions between “year” and “agroclimatic zone” or “maturity” or “month/year” were observed. For a given agroclimatic zone, January samples were richer in polysaccharides than April samples which were characterized by a highest amount in proteins and aromatic compounds. The “maturity” factor revealed that young leaves contained fewer proteins and antioxidant compounds. The “year” factor was involved in all significant interactions and confirmed the temporal character of the studied factors. The diversity of climate and soils in Cameroon must be taken into account if a certain typicity of collected Moringa Oleifera leaves, or a constant quality may be assured before their marketing phase in powder form as a dietary supplement

Infrared Spectroscopy for the Characterization and Quality Control of Moringa Oleifera : a Multivariate Approach

International audienceMoringa oleifera is known for its nutritional and therapeutic potential. This potential is linked to the chemical composition whose variability according to the ecological characteristics and development processes (from harvesting to packaging) can be significant. The influence of parameters such as altitude, weather conditions (temperature, humidity, precipitation), parts of the plant used as well as the influence of the processes for extracting active compounds, the quality of the finished product and/or its maturity level can be apprehended by statistical studies of analytical data. The ultimate goal is to use spectroscopy to ensure the quality control and traceability of different M. oleifera samples. Preliminary results on the mineral contents of Moringa plant parts (leaf, stem, bark and flower) show a differentiation depending on the geographical origin (arid zone or wetland). The use of spectroscopic technics associated to chemometric treatments allowed the differentiation of plant parts (leaf, stem and flower) on the basis of their chemical composition and gave informations on the quality of the process (ratio leaf/stem in a powder of dry material or water content for example). Water content of leaves is an important parameter during harvesting, drying, storage or industrial processing for the evaluation and the control of spoilage risks if leaves are used as food commodity. Sorption isotherms of M. oleifera leaf powders were used as models to give informations about their humidity equilibrium and their shelf life if they are used as dietary supplement. To achieve our goal, we depend on the validation of a large and representative sampling by local experts

La composition chimique de l'huile de noix (Juglans regia L.) dépend de la variété, de la localité, du processus d'extraction et des conditions de stockage : Une étude complète

International audienceThis review presents a comprehensive synthesis of walnut oil chemical composition data (major and minor compounds) collected from the literature according to the varieties and the geographic origins of walnuts, and to the oil extraction processes. Considered as influencing factors, pre-and post-harvest treatment parameters of in shell-walnut and kernels were identified and works on oil stability were discussed according to walnut pretreatment, oil extraction processes and their storage conditions. Most studies dealt with the quantification of fatty acids and tocopherols. There has been less interest in the triacylglycerol composition and minor components (sterols, volatiles, phenolic compounds) of the oil. The volatile compound profiles were mainly determined to define the oxidative degree of oil and to better understand the effect of the fatty acid degradation on the organoleptic properties of oil. Unfortunately, sensory analyses were rarely performed. This review highlights a lack of knowledge on walnut sampling before oil analysis and a distortion between some results of chemical compounds. Impact of walnut variety, walnut storage and oil extraction process was documented but few studies have considered the temporal factor of harvest, the packaging and the storage conditions of oil, which influence its chemical composition and consequently its nutritional and taste qualities.Cette revue présente une synthèse complète des données sur la composition chimique de l'huile de noix (composés majeurs et mineurs) recueillies dans la littérature en fonction des variétés et des origines géographiques des noix, et des procédés d'extraction de l'huile. Considérés comme des facteurs d'influence, les paramètres de traitement avant et après récolte des noix en coque et des cerneaux ont été identifiés et les travaux sur la stabilité de l'huile ont été discutés en fonction du prétraitement des noix, des procédés d'extraction de l'huile et de leurs conditions de stockage. La plupart des études ont porté sur la quantification des acides gras et des tocophérols. La composition en triacylglycérols et les composants mineurs (stérols, volatils, composés phénoliques) de l'huile ont suscité moins d'intérêt. Les profils des composés volatils ont été déterminés principalement pour définir le degré d'oxydation de l'huile et pour mieux comprendre l'effet de la dégradation des acides gras sur les propriétés organoleptiques de l'huile. Malheureusement, les analyses sensorielles ont rarement été réalisées. Cette revue met en évidence un manque de connaissances sur l'échantillonnage des noix avant l'analyse de l'huile et une distorsion entre certains résultats des composés chimiques. L'impact de la variété de noix, du stockage des noix et du processus d'extraction de l'huile a été documenté mais peu d'études ont considéré le facteur temporel de la récolte, le conditionnement et les conditions de stockage de l'huile, qui influencent sa composition chimique et par conséquent ses qualités nutritionnelles et gustatives

NIR PLS prediction of quality parameters of olive oils at different stage of ageing

International audienceThe chemical composition of olive oil depends on olive variety, climatic conditions during growth and olive maturity. There are mainly composed of triglycerides (95 to 98%) and minor compounds include phenolic compounds, tocopherols, alcools, esters, hydrocarbons, and pigments (Cert, Moreda, & Pérez-Camino, 2000). The nutritional and health benefits of olive oil can be attributed to antioxidants (phenolic compounds and tocopherols) and to the fatty acid composition of triglycerides: an abundance of monounsaturated fatty acid (MUFA), namely oleic acid, compared to saturated fatty acids (SFA) and an appropriate presence of polyunsaturated fatty acids (PUFA) especially ω6 and ω3 essential fatty acids. This leads to a good influence on cardiovascular diseases and cellular ageing (López-Miranda et al., 2010). But unsaturated lipids are particularly susceptible to oxidative phenomena that occur during cooking processing and storage. A series of reactions such as hydrolysis, oxidation, polymerisation, isomerisation and cyclisation (at 180°C or above) (Gertz, Klostermann, & Kochhar, 2000) may occur and lead first to the formation of peroxides and hydroperoxides, instable products that may involved into secondary oxidative products as hydrocarbons, alcohols, aldehydes and ketones which may also be oxidized in carboxylic acids (Gertz et al., 2000). Oxidized oil will have a less nutritional interest than a well conserved oil (Frankel, 1984).To estimate the oil quality, the international oleic council (IOC) and the international standardisation organisation (ISO) recommend to measure peroxide value (PV) (ISO 3960, 2007), spectroscopic indexes (K232 and K270) (International Olive Council, 2001a) the p-anisidine value (AV) (ISO TC34/SC 11, 2003), free acidity (FA) (ISO 660, 2009) and fatty acid composition by chromatographic analyse (International Olive Council, 2001b). PV, often used to evaluate the degree of oxidation, measures the amount of total peroxides. It increases at the beginning of the oxidation process and then decreases, because peroxides are transient chemical compounds. Its evolution depending on the heating time and temperature, is related to the antioxidant concentration of oil (Bešter, Butinar, Bučar-Miklavčič, & Golob, 2008; Nissiotis & Tasioula-Margari, 2002). K232 and K270 indexes measure the specific absorbance at 232 and 270 nm respectively of the conjugated dienes and trienes formed in autooxidation process from the hydropreroxides of unsaturated fatty acids and their oxidation products (Pristouri, Badeka, & Kontominas, 2010; Shahidi & Wanasundara, 2002). AV provides a good estimation of aldehydes especially conjugated dienals and 2-alkenals, main secondary oxidation compounds (Shahidi & Zhong, 2005), and completes the PV determination (Casal, Malheiro, Sendas, Oliveira, & Pereira, 2010). The total oxidation value (TOTOX = 2 PV + AV) gives a better estimation of the progressive oxidative deterioration of fats and oils because it measures both hydroperoxides and their breakdown products, i.e. aldehydes (Poulli, Mousdis, & Georgiou, 2009). Determination of fatty acids composition (which constitute the triacylglycerols) allows to follow their evolution individually (Bešter et al., 2008 ; Bouaziz, Fki, Jemai, Ayadi, & Sayadi, 2008) or grouped in class (SFA, MUFA and PUFA) (Casal et al., 2010; Maggio et al., 2009).In this work, two oils were studied because of their own method of manufacture, which is supposed to induce a difference in oil composition. Knowing that the degradation rate of olive oil was influenced by temperature, light, presence of oxygen and storage time, the aim was to study the stability of oils stored in different conditions of light, temperature and oxygen supply, via the determination of the quality indices and to evaluate the combined effects of these storage parameters. , Fourier transform infrared (FT-IR) spectroscopy has become an emerging well-accepted analytical technique, due to its simplicity with advantages in terms of cost per sample. It achieves high analysis speed and requires little or no sample preparation. FT-IR spectroscopy has been widely used as an analytical tool in various laboratories and industrial sectors such as food agricultural, petrochemical, textual and pharmaceutical. Up to date, a lot of studies have been published on the utilization of Near and Mid FT-IR for authentication, identification or classification of many agro-foods, notably olive oils (Casale et al., 2010a; Dupuy et al., 2010b; Galtier et al., 2007; Sinelli et al., 2010) and table olives (Casale et al., 2010b; Dupuy et al., 2010a) by multivariate statistical analysis of spectral data. Near FT-IR (FT-NIR) has been applied on olive leaves to discriminate between the juvenile and adult leaves (Leon & Downey, 2006) and for prediction of nutritive composition (Fernandez-Cabanas, Garrido-Varo, Delgado-Pertinez & Gomez-Cabrera, 2008). The present work investigates this methodology for two olive oils aged under different storage conditions

Solid state fermentation pilot-scaled plug flow bioreactor, using partial least square regression to predict the residence time in a semicontinuous process

International audiencePlug flow bioreactor (PFB) used in solid state fermentation gives the possibility to have semicontinuous culture. However, it is complicated to follow a single particle during its residence inside the bioreactor and to therefore study precisely the culture process all along the device. In this study, semicontinuous production of fungal compounds was successfully obtained by cultivating Aspergillus niger with a PFB prototype. Kinetic productions of the same metabolites along the bioreactor were obtained at laboratory scale to predict the residence time of the particles inside the PFB from Partial Least Square (PLS). This original methodology allowed (1) the comparison between the production kinetics at the two production scales (pilot and laboratory) and (2) the observation of eventual changes following the scale-up of the process offering a good overall insight of the PFB performance

An iterative selection algorithm: A decision aid to select the best extra virgin olive oils competing in an international contest

International audienceExtra virgin olive oils (EVOO) are typically categorized in accordance with the nature of their fruitiness (green or ripe) and the intensity of their fruitiness (delicate, medium, or robust) in accordance with the proposal of the competitor (producers) or a chemical analysis certificate established by an official panel. Depending on the category in which EVOO participates, its categorization may either disadvantage or benefit its rating. To eliminate this ambiguity and maximize an EVOO's probability of winning, the jury of the International "Word Edible Oils" competition use an innovative method to assess the EVOOs using a restricted amount of sensory descriptors (aromatic maturity, structure and fruitiness). Independent of category, the best EVOOs with comparable organoleptic properties have been identified using a statistical processing of the scores of the three descriptors. This is an iterative version of the technique developed by Wootton, Sergent, and Phan-Tan-Luu (iWSP), which generates subspaces that enable a local selection of the best EVOOs in a 2D aromatic maturity vs structure plan. In each subspace, their ranking is determined by their fruitiness score. An iterative approach that takes into consideration the changing sequence of subspace formation and the varying size of the subspace enables the selection of the best EVOOs. The development of the iWSP algorithm enabled the elimination of category constraints, (ii) the selection of the best EVOOs among those with comparable organoleptic features based on a large number of simulations, and (iii) the creation of a ranking to aid the jury's final judgment

Fingerprints for recognition of French monovarietal walnut oils making up the Périgord Protected Designation of Origin (PDO)

International audienceThis study is the first to be carried out for varietal recognition of cold-pressed oils from P´erigord walnuts(France). Produced from Corne, Franquette, Grandjean and Marbot varieties, the Perigord oil is currently the solewalnut oil to benefit of a Protected Designation of Origin (PDO, obtained in 2020). The Fernor variety shouldpotentially be added to the PDO. The compositions of fatty acids (FA), triacylglycerols (TAG) and tocopherols ofthe five walnut varieties were determined from 176 samples over three harvest years. Data of FA and TAG wereused to generate graphical representations named “morphotypes” corresponding to each variety. These morphotypesprovided rapid visual identification of varieties and their specific markers. Partial Least SquareDiscriminant Analysis (PLS1-DA) was used to predict the four Perigord walnut varieties with a control chartapproach to estimate the degree of reliability of the prediction. Models from FA contents provided the best resultswith a percentage of samples recognized as belonging to the predicted variety equal to 93%, 81%, 75% and 86%for the varieties Corne, Franquette, Grandjean and Marbot respectively. These approaches offer the advantage tobe evolutive and can be supplemented by annually collected data