A Method for the Allotment of Maize Contaminated by Toxins

Deoxynivalenol and fumonisins pose a health concern and have economic consequences, so the European regulation CE 1126/2007 dictates the maximal content allowed in cereals. The direct measurement of mycotoxin content using the established method is not only time-consuming and tedious, but also destructive and cannot be used in a silo. Alternative tools such as infrared spectroscopy are therefore being studied. For the present investigation, spectral data collected from maize kernels contaminated naturally by mycotoxins were studied to predict the risk of deoxynivalenol and fumonisins. Discriminant models were used to create and identify batches that satisfy regulations for animal or human consumption

Ozone Effects on Botrytis cinerea Conidia using a Bubble Column: Germination Inactivation and Membrane Phospholipids Oxidation

Ozone treatments were applied on conidia aqueous suspensions in order to determine theminimal applied ozone dose to limit conidia germination and to observe the mechanismsinvolved in the spores inactivation. Conidia germination was significantly reduced, bubbling forat least 0.5 min as a gas with a minimal ozone concentration of 1 g.m−3. The applied ozone dosesinduce the membrane phospholipids oxidation, determined by the malondialdehyde quantifica-tion. Membrane phospholipids oxidation and inactivation rate are correlated. So, lipid peroxida-tion and consequently the alteration of the membrane integrity are involved in the antifungalaction of ozone

Physicochemical characterization and study of molar mass of industrial gelatins by AsFlFFF-UV/MALS and chemometric approach

Industrial gelatins have different physicochemical properties that mainly depend of the raw materials origin and the extraction conditions. These properties are closely related to the molar mass distribution of these gelatins. Several methods exist to characterize molar mass distribution of polymer, including the Asymmetrical Flow Field Flow Fractionation method. The goal of this study is to analyze the relationship between physicochemical properties and the gelatins molar mass distribution obtained by Asymmetrical Flow Field Flow Fractionation. In this study, 49 gelatins samples extracted from pig skin are characterized in terms of gel strength and viscosity and their molar mass distribution are analyzed by Asymmetrical Flow Field Flow Fractionation coupled to an Ultraviolet and Multi Angle Light Scattering detector. This analytical method is an interesting tool for studying, simultaneously, the primary chains and the high-molar-mass fraction corresponding to the polymer chains. Correlation analysis between molar mass distribution data from the different fractions highlights the importance of high molar mass polymer chains to explain the gel strength and viscosity of gelatins. These results are confirmed by an additional chemometric approach based on the UV absorbance of gelatin fractograms to predict gel strength (r2Cal = 0.85) and viscosity (r2Cal = 0.79)

Modulating analytical characteristics of thermovinified Carignan musts and the volatile composition of the resulting wines through the heating temperature

The impact of two temperature levels (50 °C and 75 °C) and heating times (30 min and 3 h) on the composition of thermovinified musts and wines from Carignan was investigated at the laboratory scale in 2014 and 2015. The heating temperature had a significant impact on the extraction of amino acids and a probable thermal degradation of anthocyanins was noted at 75 °C. In 2014, musts from grapes that underwent a heat treatment at 50 °C for 3 h had a similar level of phenolic compounds as those treated at 75 °C for 30 min. This indicates that the reduction of the heating temperature in some vintages can be compensated for through an extension of the heating period. Several grape-derived molecules were impacted by the rise in temperature and wines made from grapes treated at 50 °C in most cases contained larger concentrations of geraniol, β-citronellol, β-damascenone and 3-mercaptohexanol

Influences de la quantité, de la masse moléculaire et de la conformation des macropolymères gluténiques sur la qualité technologique des farines panifiables de blé tendre (Triticum aestivum)

La recherche de critères d'évaluation des aptitudes technologiques des blés à la récolte et de critères de raisonnement des mélanges de blés lors de la fabrication des farines étaient les deux questions qui ont motivé ces travaux. Dans un premier temps, nous avons cherché à évaluer les liens entre caractéristiques des protéines insolubles au SDS (Fi) et la valeur technologique. En observant l'insolubilisation des protéines au cours du remplissage du grain, nous avons montré que la Fi était indispensable à une expression de la qualité. Puis, en introduisant une variabilité intragénotypique, il s'est avéré qu'au-delà de la quantité de Fi, la Distribution des Masses Moléculaires (DMM) mesurées par HPSEC-MALLS de la Fi rendait compte des écarts de qualité entre lots de blé. Enfin, l'étude de mélange de blés a permis de mettre en évidence que la complémentarité des aptitudes technologiques des farines dépendait du cultivar et que la quantité de Fi résiduelle dans la pâte ne réflétait pas le potentiel technologique du mélange. Dans un second temps, pour améliorer la compréhension entre structure du réseau du gluten et fonctionnalité des gluténines, nous avons suivi les modifications que subissaient les protéines au cours du pétrissage. Cette étude a permis de confirmer le rôle important que l'eau joue sur la conformation des protéines lors de l'hydratation. L'eau entraîne un déploiement des gluténines, plus ou moins rapide selon le cultivar ou le mode de pétrissage utilisé. Ces résultats ont permis d'étudier les influences relatives de la polymérisation et de l'agrégation sur l'insolubilisation des protéines, et sur l'expression des aptitudes technologiques. Ils nous permettent également d'affirmer que, bien que les ponts disulfures soient indispensables à la définition d'un réseau protéique, les liaisons et interactions faibles entre protéines ou entre l'eau et les protéines sont déterminantes dans cette définition.TOULOUSE-ENSIACET (315552325) / SudocALBI-ENSTIMAC (810042301) / SudocSudocFranceF

Contribution à l'amélioration de la qualité technologique des farines de blé (Triticum aestivum L.) par l'apport foliaire d'azote et de soufre (implication des protéïnes de réserve et du glutathion)

Dans l'objectif d'améliorer la qualité technologique des farines, l'influence des applications foliaires d'azote et de soufre sur les protéines de réserve et sur le glutathion dans le grain de blé tendre, a été étudié. Dans un premier temps, nous avons mis au point une technique de mesure du 34S dans les différentes parties de la plante et les différentes classes protéiques, par analyse élémentaire couplée à la spectrométrie de masse de rapports isotopiques. A partir des mesures de traceurs 34S et 15N, nous avons démontré que le soufre et l'azote apportés par voie foliaire au stade anthèse et post anthèse sont incorporés dans le grain et dans les protéines de réserve. dans un deuxième temps, nous avons caractérisé la teneur et la composition en protéines de réserve et en glutathion à l'aide de différentes techniques analytiques (analyse élémentaire; chromatographie liquide haute performance d'exclusion stérique, en phase inversée et par échanges d'ion.) Nous avons montré que des fertilisations foliaires d'azote et de soufre modifient la synthèse des gluténines et des gliadines, ainsi que des différentes formes du glutathion présentes dans le grain.TOULOUSE-ENSAT-Documentation (315552324) / SudocSudocFranceF

Ozonation of three different fungal conidia associated with apple disease: Importance of spore surface and membrane phospholipid oxidation

Although ozone (O-3) is a well-known bactericide and fungicide, the required dose of ozone can depend significantly on the targeted pathogens. The present research evaluates the variation in sensibility to ozone of three fungal species from a single fungal group. The three fungal species selected,Venturia inaequalis,Botrytis cinerea, andNeofabreae alba, belong to the Ascomycota group and attack apples. The fungi were exposed to ozone by bubbling directly into the spore solutions (treatment period ranged from 0.5 to 4 min, ozone concentration in inlet gas ranged from 1 to 30 g/m(3)). The rates of germination were determined, and the level of peroxidation of the lipid membrane was quantified based on the malondialdehyde (MDA) production. The results indicate that ozone effectively reduces spore development and suggest that the fungi differ in sensitivity. To reduce by 50% the spore germination rate ofN. alba,B. cinerea, andV. inaequalisrequires ozone doses of 0.01, 0.03, and 0.07 mg/ml, respectively. Spore sensitivity seems to be directly linked to spore surface. For all the fungal species, the MDA level and the level of spore inactivation both increase with ozone dose, which confirms that ozone alters the cell membrane

Classification of Popcorn (<i>Zea mays</i> var. <i>everta</i>) Using Near-Infrared Spectroscopy to Assess Zearalenon Risk Mitigation Strategies

This study delves into the detection of the mycotoxin zearalenone (ZEA) in popcorn, aligning with the broader goal of ensuring food safety and security. Employing fast, non-destructive near-infrared spectroscopy, the research analyzes 88 samples collected in France. In order to emphasize the dedication to robust methodologies, an essential element of sustainable practices, the assessment of various validation methods becomes significant. Six CART classification tree models, with a threshold of 68 µg/kg, are meticulously assessed. The study not only scrutinizes various validation strategies but also explores the concrete impact of the detection process, emphasizing sustainable practices. Model F (Kennard and Stone) is chosen for its commendable ability to generalize and its balanced performance, boasting 91% precision and 57% recall. Notably, this model excels in specificity, minimizing false positives and contributing to food safety. The identification of key wavelengths, such as 1007 nm, 1025 nm, and 1031 nm, highlights the potential for targeted interventions in crop management. In conclusion, this research showcases near-infrared spectroscopy as a sustainable approach to fortifying the food safety of popcorn, paving the way for advancements in ZEA risk detection and prevention, while minimizing environmental impact

Changes in SDS Solubility of Glutenin Polymers During Dough Mixing and Resting

International audienceAn on-line coupling of HPSEC-MALLS and a RP-HPLC procedure were used to characterize and to reveal the polydispersity of the glutenin polymers of doughs during mixing and resting. Experiments involved doughs prepared from several samples of a common French wheat cultivar (Soissons) differing in total amount of SDS-unextractable glutenin polymers. During dough mixing the amounts, the size distribution of protein and the glutenin subunit composition within the SDS-unextractable polymers changed. However, the major changes in SDS-unextractable glutenin content and size distribution occurred before the peak MT was reached, while detectable changes in subunit composition occurred also after the peak MT. Even if sonication, which was used to solubilize the total wheat glutenin, can narrow down the glutenin size distribution, HPSEC-MALLS revealed a close relationship between the SDS solubility of the glutenin polymers and their size distribution confirming a depolymerization and repolymerization hypothesis. During the depolymerization of the SDSunextractable polymers, glutenin subunits were released in nonrandom order, which was indicative of the polymers' having a hierarchical structure. Some HMW-GS (specially HMW-GS 1Dx5) were particularly resistant to the depolymerization mechanism. This suggested that the subunit plays a major role in forming the backbone of the SDS-unextractable polymers consistent with its potential to form branched structure. These studies suggest that the SDSunextractable polymers in flours have a well-ordered structure that can be modified by dough mixing and resting

Assessing macro- (P, K, Ca, Mg) and micronutrient (Mn, Fe, Cu, Zn, B) concentration in vine leaves and grape berries of vitis vinifera by using near-infrared spectroscopy and chemometrics

International audienceMacronutrients (phosphorus, potassium, calcium, and magnesium) and micronutrients (manganese, iron, copper, zinc, and boron) play an essential role not only in the general physiology of vines but also in the quality of wine produced. The quantity of each nutrient in the vine is generally determined by analyzing the leaf blades or petioles, but this approach imposes a typical delay of two weeks between sampling and receiving the results, which precludes real-time detection of nutritional deficiencies (e.g., boron deficiency at flowering). Therefore, a method to rapidly analyze vine organs is highly desirable. One candidate for such a method is near-infrared (NIR) reflectance spectroscopy coupled with chemometric methods, based on which winegrowers have already developed prediction models. This approach is widely used today in agriculture. The aim of the present study is to determine whether NIR spectroscopy can be used to obtain accurate information about the nutritional status of vines. In this study, we focus on the mass of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and boron (B) contained in different vine organs (leaf blades, petioles and berries) over the course of a year. The concentration of these elements was determined based on NIR absorbance spectra from 677 samples of various dried vine organs. Partial least square models for classification and prediction were then developed based on raw and pretreated spectra for each organ, following which the models were tested on an external prediction set. The results show that, for Ca and Mg, all organ models can be used routinely for classification or prediction. For prediction, the Ca (Mg), model produces r2 = 0.88, 0.70, and 0.72 (0.60, 0.72, and 0.80) for leaf blades, petioles, and berries, respectively. Only for leaf blades (berries) is the Ca (Mg) model sufficiently accurate to be used for prediction. For berries, the P, K, and Zn models produce r2 in prediction of 0.77, 0.79, and 0.82, respectively. For petioles, the K model proves reliable for prediction, with r2 = 0.76. The Fe, Cu, and B models produce r2 = 0.72, 0.71, and 0.52, which are suitable for classification but not for prediction. Finally, for leaf blades, the Fe and Cu models produce r2 0.58 and 0.61, respectively, in prediction and thus can be used routinely for classification