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International audience; Cell wall polysaccharides (CWPs) and phenolic substances, e.g., procyanidins, widely co-exist in fruit and vegetables and interact in complex patterns during chewing, food processing and in vivo digestion, impacting the food physicochemical and nutritional qualities. Interactions were characterized between two procyanidins and heterogeneous CWPs (four native and twelve modified) from apple, beet and kiwifruit presenting various chemical compositions and physical structures. ATR-FTIR discriminated the complexes from the initial purified procyanidins and CWPs. Langmuir isotherms and ITC indicated that native CWPs, from all botanical origins, had a higher affinity for procyanidins than the modified ones, which were all poorer in pectins. The CWPs thatinteract more with procyanidins were characterized by their high pectin content and linearity, and high porosity. Increasing the molecular size of procyanidins increased their complexation with CWPs. This work is an important guide to the encapsulation and controlled release of active compounds and the subsequent respective digestive behavior and human health.

International audience; The potential of MIRS was investigated to: i) differentiate cooked purees issued from different apples and process conditions, and ii) predict the puree quality characteristics from the spectra of homogenized raw apples. Partial least squares (PLS) regression was tested both, on the real spectra of cooked purees and their reconstructed spectra calculated from the spectra of homogenized raw apples by direct standardization. The cooked purees were well-classified according to apple thinning practices and cold storage durations, and to different heating and grinding conditions. PLS models using the spectra of homogenized raw apples can anticipate the titratable acidity (the residual predictive deviation (RPD) = 2.9), soluble solid content (RPD = 2.8), particle averaged size (RPD = 2.6) and viscosity (RPD ≥ 2.5) of cooked purees. MIR technique can provide sustainable evaluations of puree quality, and even forecast texture and taste of purees based on the prior information of raw materials.

International audience; The contribution of ATR-FTIR spectroscopy to study cell wall polysaccharides (CWPs) was carefully investigated. The region 1800-800 cm− 1 was exploited using principal component analysis and hierarchical clustering on a large range of different powders of CWPs based on their precise chemical characterization. Relevant wavenumbers were highlighted for each CWP: 1035 cm− 1 was attributed to xylose-containing hemicelluloses, 1065 and 807 cm− 1 to mannose-containing hemicelluloses, 988 cm-1 to cellulose, 1740 and 1600 cm-1 to homogalacturonans according to the degree of methylation. Some band positions were affected by macromolecular arrangements (especially hemicellulose-cellulose interactions). However, as arabinan and galactan did not revealdistinctive absorption bands, ATR-FTIR spectroscopy did not allow the discrimination of cell walls differing by the abundance of these polysaccharides, e.g., those extracted from apple and beet. Therefore, the application of ATR-FTIR could remain sometimes limited due to the complexity of overlapping spectra bands and vibrational coupling from the large diversity of CWP chemical bonds.

International audience; Cell wall (CW) degradation causes texture loss of plant-based products after processing. However, these losses differ in intensity, which could be due to cell wall structure or plant tissue internal pH conditions. To distinguish these two factors, CWs isolated from apple, beet and kiwifruit were subjected to boiling at pH 2.0, 3.5 and 6.0. Pectin depolymerization was the least pronounced at pH 3.5, while galacturonic acid contents of all CWs decreased at pH 6.0 due to the β-elimination. Pectins were solubilized, and their size decreased with increased pH during CW treatment. At pH 6.0, degrees of methylation decreased mostly in apple and beet CWs while galactose decreased more in kiwifruit CW. At pH 2.0, arabinan was lost in apple and beet CW due to acid hydrolysis. Apple CW was the most susceptible to degradation either at pH 2.0 or 6.0, while beet CW was more degraded at pH 2.0. In contrast, kiwifruit CW was the least susceptible to degradation whichever the pH. Acid hydrolysis and β-elimination appeared to be common mechanisms that cause loss of neutral sugars, often from pectin side chains, and galacturonic acid, respectively, but their effects were of different intensities. This work has a guiding significance for improving texture in the thermally canning process.

International audience; The aim of this study was to identify optimal storage conditions able to preserving date palm quality and minimising their loss in the supply chain. Hence, the effect of storage at -18, 0, 2 and 4 ◦C for 3, 6 and 9 months during two harvest seasons (2017 and 2018) on sugars, organic acids, polyphenols and cell wall yields and composition of ‘Deglet Nour’ Tunisian dates, were studied. Mid Infrared Spectroscopy (MIR) as a non-targeted method allowed to highlight a year effect on chemical composition and to discriminate samples stored at 4 and 2 ◦C regarding to major components (moisture, sugars, organic acids.). Cell wall yields were stable during the time. However, galactose from pectin side chains decreased with time, causing an increase of lignin, cellulosic glucose, fucose and rhamnose. Procyanidins, accounting for 98% of total polyphenols, were not affected bystorage. Regarding quality parameters stability, stored fruits at - 18 ◦C could be the solution for a long term storage but due to its high energetic costs, 2 ◦C must be the optimal temperature with a lower time.

International audience; Vis-NIRS, MIRS, and a combination of both coupled with PLS and machine learning were applied to i) trace the composed proportions of different apple varieties in formulated purees and ii) predict the quality characteristics of formulated purees from spectral information of initial puree cultivars. The PLS models could estimate proportions of each apple cultivar in puree mixtures using MIR spectra (RMSEP 3.6), especially for Granny Smith (RMSEP = 2.7%, RPD = 11.4). The concentration profiles from multivariate curve resolutionalternative least squares (MCR-ALS) made possible to reconstruct spectra of formulated purees. MIRS technique was evidenced to predict the final puree quality, such as viscosity (RPD>4.0), contents of soluble solids (RPD = 4.1), malic acid (RPD = 4.7) and glucose (RPD = 4.3), based only on the spectral data of composed puree cultivars. Infrared technique should be a powerful tool for puree traceability, even for multicriteria optimization of final products from the characteristics of composed puree cultivars before formulation.

International audience; The mid-infrared spectroscopy (MIRS) was investigated as a tool to improve the quality of tomato products considering its implementation at different steps along the processing chain. Models have been developed using partial least square (PLS) regression to predict the quality of raw and processed tomatoes. A relevant method (Multi-year Combining models) consisting in adding early-season tomatoes data within models developed using data of previous years, was shown as the most efficient and adapted to realistic industry conditions. MIRS predicted, in external validation, soluble solids content (R2 0.95), titratable acidity (R2 0.88) and dry matter content (R2 0.81) with a high accuracy of 0.1°Brix, 2.8 mmol H+/kg and 0.4% respectively. Secondly, MIRS was used to classify tomato products depending on processing methods (hot- or cold-break) or varieties using factorial discriminant analysis (FDA) based only on spectral data. MIRS was assessed as an efficient tool to classify processed tomato purees according to process, year and variety, more accurately than the classification obtained with the reference data. A possible implementation of MIRS was suggested at three strategic steps along the processing chain to i) characterize the incoming raw material, ii) monitor the matrix changes during processing and iii) control the final products.

International audience

International audience; The potential of NIRS was investigated on both apples and purees to (i) examine factors involving quality variability (variety, agricultural practice, cold storage, puree mechanical refining level) and (ii) establish the link between quality traits before and after processing in order to predict the quality characteristics of purees from spectral information of raw apples. Apples and purees were well-classified at over 82% and 88% according to varieties and storage times respectively. The PLS models showed a good ability to estimate puree characteristics from spectra acquired on corresponding apples such as viscosity (R2 > 0.82), cell wall content (R2 > 0.81) and also dry matter (R2 > 0.83), soluble solids content (R2 > 0.80) and titratable acidity (R2 > 0.80). NIR technique should be a useful tool for industry insofar as it can give a reliable assessment of texture and taste of the final products based on the non-destructive fresh materials evaluation.

Near (NIR) and Mid (MIR) infrared spectroscopy were investigated as rapid methods for evaluating quality traits of fresh passion fruit pulp. Models to predict soluble solids content (SSC), titratable acidity (TA), glucose (GLC), fructose (FRU), sucrose (SUC) and vitamin C (ascorbic acid) were developed using linear partial least square (PLS) regression analysis. The PLS models in MIR provided better prediction results than in NIR. Prediction models in MIR were better for SSC (R2v = 0.95), TA (R2v = 0.86), glucose (R2v = 0.93), fructose (R2v = 0.84) and sucrose (R2v = 0,74). However, due to its low level in pulp, ascorbic acid was not satisfactorily predicted either by NIR or MIR.

National audience; The objective of this work is to evaluate the possibility of using mid-infrared spectroscopy as a rapid analytical method to monitor the change in stored ready-made meals over time, for example oxidation phenomena occurring particularly in ready-made meals in plastic packaging. Six ready-made meals models (lentils, mashed potatoes, mashed potatoes with cheese, béchamel sauce, vegetable soup, Bolognese sauce) were prepared and packaged in plastic bags. They were stored at 23°C and at a partial oxygen pressure of 96 kPa to accelerate the oxidation phenomena. Two plastic packaging, Alu and Alox, were used presenting in these conditions an oxygen permeability of respectively 0.028 and 0.040 cm3/(packaging.day). Three bags of each ready-meal x plastic packaging combinations were sampled at 6 different times: T0 the start of the experiment, 20 days (equivalent to 3 months), 40 days (equivalent to 6 months), 59 days (equivalent to 9 months), 79 days (equivalent to 12 months) and 119 days (equivalent to 18 months). Samples were then frozen at −20°C until measurements. After thawing, samples were directly, without grinding, measured in attenuated total reflectance mid-infrared spectroscopy between 4000 and 650/cm performing five replications to evaluate the sample heterogeneity. Multivariate analyses applied on spectral data allowed to highlight some changes in the global profile. For example, in the case of Bolognese sauce, samples were clearly discriminated (i) from 12 months, (ii) according to the packaging at 18 months with a greater oxidation in the Alox packaging. The eigenvectors allowed to identify several clear absorption bands which increased over storage, such as 2918/cm, 2850/cm, 1741/cm and 1164/cm. 吀ese absorption bands could be attributed to fats, which thus appeared to have a major effect in sample discrimination. The Mid-infrared spectroscopy was shown in this study to be a simple, rapid and relevant tool for discriminating the oxidation state of canned ready-made meals and might be used to determine their shelf-life.

International audience; The composition of pomegranate peel, the main by-product during pomegranate processing, and some of the characteristics of the water-soluble pectins were investigated. Four tunisian pomegranate peels were subjected to hot aqueous extractions (86 °C, 80 min, 20 mM nitric acid). Pomegranate peels yielded between 6.8% and 10.1% pectins. The extracted pectins were low methylated and were characterized by the predominance of homogalacturonan regions. Principal component analysis applied on FT-IR spectral data in the region between 4000 and 650 cm−1 differentiated the samples according to their degree of methylation. At pH 3, in the presence of 0.7% pectin, all solutions showed a rapid gel formation with G′ > G″. With decreasing temperature from 90 °C to 10 °C, G′ increased to reach a plateau at 10 °C. The variation in the pectin gel formation between varieties was attributed to difference in pectin characteristics particularly the hydrodynamic volume and the neutral sugar content.

Modification of cell walls of apple, red beet and kiwifruit by heating in acid conditions: common and specific responses. 15th Cell wall meeting

International audience

International audience; In recent years, decreased cost, miniaturisation and advances in computing power and data processing software have led to widespread introduction of Fourier-transform (FT) spectrometers across different disciplines. In this review, applications of FT mid infrared (FT-MIR) spectroscopy are summarised covering the analysis of fresh fruit and vegetables, and some of their processed products (juices, jam, oil, wine). The paper also outlines basic principles of vibrational spectroscopy in the MIR region, using sugars and acids in fruit juices as exemplars of spectral interpretation. Laboratory-based spectrometers, FT-MIR microspectroscopy for high-resolution mapping and portable, hand-held units for field work are described. Applications involving these systems, which extend to more than 40 genera, and more than 40 different crop attributes, include; assessing the maturity or quality attributes of produce, screening progeny from breeding programmes, determination of bioactive contents and plant metabolites, determining the extent of adulteration and authenticating products for type or geographic location, and localisation of metabolites within plant cells. Principles outlining best-practice for developing calibration models in fruit and vegetable-based systems are also included.

Fast advancement of machine learning methods and constant growth of the areas of application open up new horizons for large data management and processing. Among the various types of data available for analysis, the Fourier Transform InfraRed (FTIR) spectroscopy spectra are very challenging datasets to consider. In this study, machine learning is used to analyze and predict a rheological parameter: firmness. Various statistics have been gathered including both chemistry (such as ethylene, titrable acidity or sugars) and spectra values to visualize and analyze a dataset of 731 biological samples. Two-dimensional (2D) and three-dimensional (3D) principal component analyses (PCA) are used to evaluate their ability to discriminate for one parameter: firmness. Partial least squared regression (PLSR) modeling has been carried out to predict the rheological parameter using either sixteen physicochemical parameters or only the infrared spectra. We show that (i) the spectra alone allows good discrimination of the samples based on rheology, (ii) 3D-PCA allows comprehensive and informative visualization of the data, and (iii) that the rheological parameters are predicted accurately using a regression method such as PLSR; instead of using chemical parameters which are laborious to obtain, Mid-FTIR spectra gathering all physicochemical information could be used for efficient prediction of firmness. As a conclusion, rheological and chemical parameters allow good discrimination of the samples according to their firmness. However, using only the IR spectra leads to better results. A good predictive model was built for the prediction of the firmness of the fruit, and we reached a coefficient of determination R2 value of 0.90. This method outperforms a model based on physicochemical descriptors only. Such an approach could be very helpful to technologists and farmers.

International audience; FT-NIR models were developed for the nondestructive prediction of soluble solid content (SSC), titratable acidity (TA), firmness and weight of two commercially important apricot cultivars, ‘‘Hacıhalilog˘lu’’ and ‘‘Kabaas¸ı’’ from Turkey. The models constructed for SSC prediction gave good results. We could also establish a model which can be used for rough estimation of the apricot weight. However, it could not be possible to predict accurately TA and firmness of the apricots with FT-NIR spectroscopy. The study was further extended over 3 years for the SSC prediction. Validation of the both mono and multi-cultivar models showed that model performances may exhibit important variations across different harvest seasons. The robustness of the models was improved when the data of two or three seasons were used. It was concluded that in order to developed reliable SSC prediction models for apricots the spectral data should be collected over several harvest seasons.

Edaphic cyanobacteria and algae have been extensively studied in dryland soils because they play key roles in the formation of biological soil crusts and the stabilization of soil surfaces. Yet, in temperate agricultural crop soils, little is understood about the functional significance of indigenous photosynthetic microbial communities for various soil processes. This study investigated how indigenous soil algae and cyanobacteria affected topsoil aggregate stability in cereal cropping systems. Topsoil aggregates from conventional and organic cropping systems were incubated in microcosms under dark or photoperiodic conditions with or without a treatment with an herbicide (isoproturon). Physicochemical parameters (bound exopolysaccharides, organic carbon) and microbial parameters (esterase activity, chlorophyll a biomass, and pigment profiles) were measured for incubated aggregates. Aggregate stability were analyzed on the basis of aggregate size distribution and the mean weight diameter (MWD) index, resulting from disaggregation tests. Soil photosynthetic microbial biomass (chl a) was strongly and positively correlated with aggregate stability indicators. The development of microalgae crusts in photoperiodic conditions induced a strong increase of the largest aggregates (>2 mm), as compared to dark conditions (up to 10.6 fold and 27.1 fold, in soil from organic and conventional cropping systems, respectively). Concomitantly, the MWD significantly increased by 2.4 fold and 4.2 fold, for soil from organic and conventional cropping systems. Soil microalgae may have operated directly via biochemical mechanisms, by producing exopolymeric matrices surrounding soil aggregates (bound exopolysaccharides: 0.39–0.45 μg C g−1 soil), and via biophysical mechanisms, where filamentous living microbiota enmeshed soil aggregates. In addition, they may have acted indirectly by stimulating heterotrophic microbial communities, as revealed by the positive effect of microalgal growth on total microbial activity. The herbicide treatment negatively impacted soil microalgal community, resulting in significant decreases of the MWD of the conventional soil aggregates (up to −42% of the value in light treatment). This study underscores that indigenous edaphic algae and cyanobacteria can promote aggregate formation, by forming photosynthetic microbiotic crusts, thus improving the structural stability of topsoil, in temperate croplands. However, the herbicide uses can impair the functional abilities of algal and cyanobacterial communities in agricultural soils.Originality/SignificanceEdaphic algal and cyanobacterial communities are known to form photosynthetic microbial crusts in arid soils, where they drive key ecosystem functions. Although less well characterized, such communities are also transiently abundant in temperate and mesic cropped soils. This microcosm study investigated the communities’ functional significance in topsoil aggregate formation and stabilization in two temperate cropping systems. Overall, our results showed that the development of indigenous microalgal communities under our experimental conditions drove higher structural stability in topsoil aggregates in temperate cropland soils. Also, herbicide use affected photosynthetic microbial communities and consequently impaired soil aggregation.

International audience; Infrared spectroscopy coupled with multivariate analyses such as linear regressions was applied to assess the main cell wall components of a huge diversity of fruits and vegetables belonging to 29 plant species. The methodology was tested on the raw freeze-dried powders and on their corresponding AIS (Alcohol Insoluble Solids) dried by solvent exchanges. The most informative spectral region was 1750-1035 cm−1. Excellent predictions (determination coefficient R2≥0.9 and residual predictive deviation RPD≥3.0) were obtained for AIS yields and for arabinose, total glucose, non-cellulosic glucose, total neutral sugars, methanol and starch contents in the AIS samples. The key wavenumbers were: 1740 cm-1 for total neutral sugars; 1075, 1440–1450, 1616 and 1740 cm-1 for pectins; 895, 1035–1041 and 1160-1163 cm-1 for cellulose and 1035–1041 cm-1 for lignin. Limitations of the reference methods to analyze cell wall components (biochemical assays, spectrophotometry, chromatography) affecting the prediction accuracy were also discussed.

International audience; Attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) was applied on fresh (NF), freeze-dried (FD) and cell wall materials (AIS) of raw and processed apples. These samples prepared from 36 apple sets and the corresponding 72 purees, issued from different varieties, agricultural practices, storage periods and processing conditions, were used to build models including exploratory analysis, supervised classification and multivariate calibration. Fresh and freeze-dried samples presented similar fingerprint spectral variations due to processing. ATR-FTIR directly on fresh purees satisfactorily predicted textural properties such as particle average size and volume (RPD > 3.0), while freeze-drying improved assessment of chemical (RPD > 3.2) and rheological (RPD > 3.1) parameters using partial least-squares regression. The assessment of texture and macrocomponents of purees can be obtained with a limited sample preparation. For research applications because of a need of sample preparation, changes of cell wall composition during fruit processing could be assessed in relationship with pectin degradation.

International audience; Quantifying and characterizing Extracellular Polymeric Substances (EPS) and especially exopolysaccharides (EPSac) is an issue for understanding the hydro-physical and biological functioning of the rhizosphere. However, few comparative studies of extraction techniques have been carried out on soils and none on calcareous Mediterranean soils. Three soil-bound EPS extraction techniques, i.e. Cation Exchange Resin (CER), EDTA and NaOH + Formaldhyde (NaOH + F) were compared on three contrasted Mediterranean soils. CER presented the lowest extraction efficiency of EPSac, but also the lowest contamination of EPS by extractants and extracellular compounds. Contamination with intracellular compounds was low and similar with the three methods. Mid-Infrared (MIR) spectra enabled the best discrimination of the EPS extracts when they were prepared with CER. CER is then identified to be the suitable extraction technique of EPS (including EPSac) from soils, including calcareous soils. This technique was applied on rhizospheric and bulk soils harvested in an experimental field of tomato cultivation. A rhizospheric effect was highlighted during the growth of plants of two cultivars with both the soilbound EPSac amounts (total sugar equivalent of extracted EPS) and the MIR spectra of extracted EPS. Extraction of soil-bound EPS and their further analysis by spectral and chemometric approaches is a promising way for relating EPS chemical characteristics to their biological and hydric impacts within the plant rhizosphere in a context of agro-ecological transition and climatic change.

International audience; Procyanidins and cell walls were extracted from pear at ripe and overripe stages in order to investigate the impact of ripening stage on their association. Procyanidin composition and structure remained stable at the overripe stage. Mid Infrared Spectroscopy (MIR) discriminated cell wall-procyanidin complex from initial purified cell wall material (CWM). Interactions between procyanidins and CWM isolated from the whole flesh (FL), parenchyma cells (PC), stone cells (ST) and skin (SK) at ripe and overripe stage were characterized using UV–Vis spectrometry using Langmuir isotherm formulation and Isothermal Titration Microcalorimetry (ITC). The affinity between procyanidins and CWM decreased as follows: PC > FL > ST > SK. The proportion of bound procyanidins increased at the overripe stage for all CWM and the maximal saturation level was obtained for overripe FL and ST. ITC indicated that associations between pear cell walls and procyanidins involved hydrogen bonds and mainly hydrophobic interactions for overripe PC.

International audience; Infrared spectroscopy is known as a rapid tool to study apricot fruit quality, non-destructively by near-infrared ( NIR, 800-2500 nm) range and destructively on fruit puree by mid-infrared ( MIR, 4000-650 cm(-1)) range. These techniques appear suitable for the determination of soluble solids content ( SSC) and titratable acidity ( TA). However, a major drawback is the need to repeatedly establish calibration equations, which can depend on cultivar, year, etc. The objective here was to evaluate the robustness of NIR and MIR techniques and to determine the best strategy: is it more efficient to build models every year or to build global models combining all years? Eight apricot cultivars, representative of the known apricot diversity for quality traits, have been analysed between 2005 and 2011. The most efficient strategy ( i. e., reliable calibration with a minimum of calibration) was a multi-year model, integrating a limited amount of fruit per year but incremented each year.

1. The quantitative determination of quality traits requiring spectral and classical data. In the work, the accuracy of the mid-infrared spectroscopy was investigated to predict internal quality traits in purees of fresh tomatoes. In a first time, the models of prediction were established using 50 representative samples and then these models were used to evaluate the quality traits of a large diversity of tomatoes through an experiment. Mid-infrared spectroscopy showed a good ability to estimate not only soluble solids (error of 4%) and titratable acidity (error of 5%) but also individual compounds such as glucose, fructose and citric acid (error of 4%). For malic acid, the high error of prediction (20%) was probably in relation with its low level in the studied tomatoes. Using these models, the tomato quality has been shown to depend on the following factors listed in descending importance as field/greenhouse cultivation > genotype > harvesting date > post-harvest duration. 2. The discrimination of different processed tomato matrices by the direct exploitation of spectral data. The analyses of principal components (PCA) performed on some specific spectral areas allowed the sample discrimination. A clear separation was shown between tomato purees prepared at 20, 40 and 70°C from those prepared at 90°C. An important change happened at around 70°C.

titre précédent : softening of pasteurized apricots : towards the use of biochemical indicators in the raw fruit for improved texture; Quality of canned apricots is seriously compromised by the loss of their flesh firmness during pasteurization. This work conducted a comprehensive characterization of the biochemical properties of raw apricots, as well as of the tissue softening during pasteurization using a multimethodology approach. Biochemical and textural results were analyzed to seek possible correlations, with the aim to elucidate which properties could be used as indicators in raw fruit for obtaining pasteurized products with better texture. There were large effects of cultivar, ripening stage, and intra-fruit zone on the biochemical and textural properties of apricots. The titratable acidity, amongst ethylene production, soluble solid content, and pectinolytic enzyme activities, was the biochemical property that correlated more robustly to the loss of texture. It had significant correlation coefficients of −0.9 and 0.5 with firmness of pasteurized fruit and loss of firmness, respectively. We propose titratable acidity to be used as indicator for raw material selection and/or to be modulated during apricot food processing.

Apricot polyphenols and carotenoids were monitored after industrial and domestic cooking, and after 2 months of storage for industrial processing. The main apricot polyphenols were flavan-3-ols, flavan-3-ol monomers and oligomers, with an average degree of polymerization between 4.7 and 10.7 and caffeoylquinic acids. Flavonols and anthocyanins were minor phenolic compounds. Upon processing procyanidins were retained in apricot tissue. Hydroxycinnamic acids, flavan-3-ol monomers, flavonols and anthocyanins leached in the syrup. Flavonol concentrations on per-can basis were significantly increased after processing. Industrial processing effects were higher than domestic cooking probably due to higher temperature and longer duration. After 2 months of storage, among polyphenols only hydroxycinnamic acids, flavan-3-ol monomers and anthocyanins were reduced. Whichever the processing method, no significant reductions of total carotenoids were observed after processing. The cis-β-carotene isomer was significantly increased after processing but with a lower extent in domestic cooking. Significant decreased in total carotenoid compounds occurred during storage.

International audience; Cell walls from flesh, parenchyma cells, stone cells and skin were isolated from ripe and overripe Pyrus communis L. cv “De Cloche” using the phenol-buffer method. Pear polysaccharides were solubilized from cell walls by sequential extractions with aqueous solutions of ammonium oxalate, Na2CO3, and increasing concentration of NaOH, to explore overripening impact. Cell walls were also differentiated using MIR spectral data. Stone cells contained high levels of xylose and lignin while parenchyma cells had high levels of glucose, uronic acids and arabinose. Sequential extractions revealed that pear pectins had highly branched rhamnogalacturonans and were extremely methylated. Xylans were the main hemicellulose especially for stone cells. Cellulose represented about half of all cell walls. This heterogeneous composition of pear affected differently cell wall evolutions and properties. Thus, overripening involved a decrease in arabinose and a loss of pectic side chains mostly from parenchyma cells. Changes in hemicellulose and cellulose were minor.

International audience; In this work, NIR and MIR spectroscopy was investigated and compared for predicting passion fruit ripening parameters as sugars, organic acids and carotenoids. Spectra of 56 samples of the lyophilized passion fruit were collected using an integrating sphere in NIR range and attenuated total reflectance accessory in MIR range. Individual sugars (sucrose, glucose and fructose), organic acids (malic and citric acids) and carotenoids (beta-carotene) contents were determined by reference methods. Spectral and reference data were analyzed by principal component analysis. Partial least square regression (PLSR) was used to establish calibration models. MIR technique was better than the NIR technique for glucose (R-v(2) = 0.942), fructose (R-v(2) = 0.855), sucrose (R-v(2) = 0.818), total sugar (R-v(2), = 0.914) and citric acid (R-v(2) = 0.913) content determination. On the other hand, NIR was superior for total acids (R-v(2) = 0.903) content determination. For malic acid and beta-carotene contents both methods were unsatisfactory due to low concentrations of these constituents in the passion fruits. (C) 2013 Published by Elsevier Ltd.

The French apricot production is located in the South-Eastern part of the country and focused both in the Rhone valley and close to the Mediterranean Sea. The north of the Rhone valley is characterized by a continental climate while the southern region (Rhone valley and Mediterranean area) is under warm typical Mediterranean climate. Obviously apricot fruit production depends on a specific panel of cultivars in each area of cultivation due to economic and adaptation constraints. In order to enlarge the panel of cultivars to be developed by the growers in each region an integrated breeding program is developed at a national level in France with the participation of INRA, CENTREX and CEP INNOVATION. The main goals of the breeding program are: the elaboration of cultivars suitable for a durable production (including resistance to pests and disease), production regularity (including self-fertility and quality of the flowers), and fruit quality (including taste, attractiveness, and suitability for the transport). The evaluation phase is organized in the 3 main areas of production (Perpignan, Nimes, Valence) and follows 3 complementary evaluation stages (i) observation of the hybrid on its own roots; (ii) evaluation of the best hybrids after grafting in the 3 main areas; (iii) assessment of the agronomic and commercial interest of the 'elite' accessions in small orchards. The main results issued from this program are presented: 8 registered cultivars, 4 new selections under registration, and the first PPV resistant cultivar 'Aramis' ® 'Shamade'.

International audience; The objectives of this study were (i) to test different conditions of freezing, thawing, and grinding during sample preparation and (ii) to evaluate the possibility of using mid-infrared spectroscopy for analyzing the composition of sugars, organic acids, and polyphenols in apples. Seven commercial apple cultivars were chosen for their large variability in composition (total polyphenols from 406 to 1033 mg kg −1 fresh weight). The different conditions of sample preparation affected only the phenolic compounds and not sugars or organic acids. The regression models of the mid-infrared spectra showed a good ability to estimate sugar and organic acid contents (R 2 ≥ 0.96), except for citric acid. Good predictions were obtained for total phenolic, flavan-3-ols, and procyanidins (R 2 ≥ 0.94) provided oxidation was avoided during sample preparation. A rapid and simple procedure was then proposed for phenolic compounds using sodium fluoride during sample homogenization at ambient temperature and freeze-drying before spectra acquisition. Mid-infrared (MIR) has been shown to be a suitable technique for high-throughput analysis of the major constituents in fruit juices, homogenates, and extracts. 1−7 These studies have been aimed to assay soluble solids content, titratable acidity, and the concentrations of individual sugars, organic acids, and total phenolic compounds. It would be highly beneficial if it could also be applied to the analysis of specific metabolites such as individual polyphenols. Indeed, the quantification of these compounds requires chemicals and solvents, equipment such as high-performance liquid chromatography coupled to a diode array detector, good technical skill, and time. However, the development of high-throughput analyses has been hindered by the high reactivity of some molecules such as polyphenols. Hence, this study aimed at identifying the simplest and cheapest sample preparation for MIR application for poly-phenol quantification. The fruit chosen for this methodological optimization was apple, as it is among the most consumed fruits worldwide and indeed a good source of polyphenols in the French diet. 8 A regular consumption of apples provides a large amount of polyphenolic compounds such as flavan-3-ols (procyanidins and catechins), dihydrochalcones (phloridzin), hydroxycinnamic acids (chlorogenic acid and p-coumaroyl-quinic acid), flavonols (quercetin), and anthocyanins. A large variability exists according to the studied cultivars with, for example, a variation of total phenolic content between 523 and 2724 mg kg −1 dry weight (DW) among 67 new and old apple varieties. 9

This work reports the rapid determination of apricot fruit quality traits using Fourier Transform near (NIR) and mid (MIR) infrared reflectance spectroscopy. The FT-NIR (800-2500 nm) spectra were acquired on intact fruits using an integrating sphere (diffuse reflectance). The FT-MIR spectra were acquired on fruit slurries using a horizontal ATR cell (Attenuated Total Reflectance). Relationships between spectral data and quality attributes obtained by traditional methods are evaluated by the application of chemometric techniques based on partial least squares (PLS) on fruit set divided randomly into two groups: 598 fruits for calibration and 279 for validation. The non-destructive method using NIR spectroscopy allows the prediction of soluble solids content and titratable acidity (correlation coefficient of 0.92 and 0.89, respectively, and root mean square error of prediction of 0.98% Brix and 3.62 meq.100g -1 FW, respectively). The ATR-FTIR performed on apricot slurries is well-adapted for the prediction of the individual compounds: sucrose, glucose, malic and citric acids (correlation coefficients greater than or equal to 0.92 and errors smaller than 16%). Prediction model for fructose, the minor compound in apricot, showed the lowest performance with r = 0.86 and error of validation of 18%. Moreover, the technique that consists in acquiring spectra and performing PCA on spectra allows the discrimination of apricot sets according to their ripening stages and their genetic characteristics.

Among fruit species, apricot (Prunus armeniaca L.) is characterized by a large phenotypic diversity due to its geographical origins and phylogenetic structures. At the same time, apricot production is deeply evolving under the pressure of breeding programmes. A recent increase of new registered cultivars has raised a strong interest in apricot, especially in Europe. Currently, modifications on fruit quality attributes have been observed. To estimate its incidence, 237 cultivars registered between 1950 and 2006 were analysed. Representative fruit samples collected at the maturity stage in collection orchards were observed from 2003 to 2007. Harvest period and fruit quality attributes have been characterized: fruit weight, fruit firmness, ground and blush colours, soluble solids content and titratable acidity. The incidence of genetic and geographic origins on fruit quality attributes were evaluated according to the registration period. France and the United States were the most important cultivar providers in the registration process. An enlargement of the genetic basis of the breeding stocks was observed with the use of new parents such as 'Goldrich' and 'Orangered'. An extension of the harvest season has been recently observed. Significant increases in fruit weight and blush colour can be explained by the use of new parents; while no significant variations on fruit firmness, soluble solids content and titratable acidity were observed due to the enlargement of the variability in the last registered cultivars.

International audience; French apricot production is located in the south-eastern part of the country, with a focused zone in the Rhone valley and close to the Mediterranean Sea. The north of the Rhone valley is characterized by a continental climate, while the southern region ( Rhone valley and Mediterranean area) is under a warm, typically Mediterranean climate. Obviously, apricot fruit production depends on the development of a specific panel of cultivars in each area of cultivation because of economic and adaptation constraints. In order to enlarge the panel of cultivars for growers of each region, an integrated breeding program has been developed at a national level in France with the participation of INRA, Centrex and CEP Innovation. The main goals of the breeding program are: the elaboration of cultivars suitable for durable production ( including resistance to pests and diseases), production regularity ( including self-fertility and quality of the flowers), and fruit quality ( including taste, attractiveness, and suitability for transport). The evaluation phase is organized in the three main French areas of production ( Perpignan, Nimes and Valence) with three complementary evaluation stages: ( i) observation of hybrids on their own roots ( ii) evaluation of pre-selections after grafting in the three main areas, and ( iii) 'elite' agronomic and commercial assessments in small orchards. A tough diagnosis, that includes biological, serological and molecular analysis, is conducted in parallel for assessing resistance to Plum pox virus ( PPV). The main results issued from this program are presented here, with 10 cultivars, including PPV-resistant Aramis (R) cultivars.

International audience; In this work, NIR and MIR spectroscopy was investigated and compared for predicting individual sugars (sucrose, glucose and fructose). Spectra of 56 samples of lyophilized passion fruit were collected using an integrating sphere in NIR range and attenuated total reflectance accessory in MIR range. Spectral and reference data were analyzed by principal component analysis. Partial least square regression (PLSR) was used to establish calibration models. MIR technique was better than the NIR technique for glucose (R 2 v = 0.942), fructose (R 2 v = 0.855) and sucrose (R 2 v = 0.818).

International audience; Four home procedures such as boiling in water, steaming, pressure steaming and microwave cooking were tested on 13 frozen vegetables. Folates, carotenoids and vitamin C were characterized on uncooked and cooked vegetables and illustrated a very large variability among the studied vegetables. The effect of cooking was significant but it varied according to vegetables and phytochemicals. The best method to preserve the nutritional quality could be alternatively steaming, microwaving or pressure cooking, whereas boiling was generally the less suitable method. On the fresh weight basis, boiling involved a high loss of total vitamin C (average of -51% on fresh matter) and folates (-68%) and a slight loss of lutein (-15%) and b-carotene (-9%). On the dry weight basis, it remained the less suitable for vitamin C (-44%) and folates (-65%) but not for carotenoids, as it allowed a better extractability of lutein (+9%) and β-carotene (+20%).

International audience; Many biotic and abiotic parameters affect the metabolites involved in the organoleptic and health value of fruits. It is therefore important to understand how the growers' decisions for cultivar and orchard management can affect the fruit composition. Practices, cultivars and/or year all might participate to determine fruit composition. To hierarchize these factors, fruit weight, dry matter, soluble solids contents, titratable acidity, individual sugars and organics acids, and phenolics were measured in three apple cultivars ('Ariane', 'Melrose' and 'Smoothee') managed under organic, low-input and conventional management. Apples were harvested at commercial maturity in the orchards of the cropping system experiment BioREco at INRA Gotheron (Drôme, 26) over the course of three years (2011, 2012 and 2013). The main factors affecting primary and secondary metabolites, in both apple skin and flesh, were by far the cultivar and the yearly conditions, while the management system had a very limited effect. When considering the three cultivars and the year 2011 to investigate the effect of the management system per se, only few compounds differed significantly between the three systems and in particular the total phenolic content did not differ significantly between systems. Finally, when considering orchards grown in the same pedoclimatic conditions and of the same age, instead of the usual organic vs. conventional comparison, the effect of the management system on the apple fruit quality (Fruit weight, dry matter, soluble solids content, titratable acidity, individual sugars, organic acids, and phenolics) was very limited to non-significant. The main factors of variation were the cultivar and the year of cropping rather than the cropping system. More generally, as each management system (e.g. conventional, organic…) encompasses a great variability of practices, this highlights the importance of accurately documenting orchard practices and design beside the generic type of management in such studies.

International audience; This work reports the first results concerning the rapid determination of quality traits of apricot using near (NIR) and middle (MIR) Fourier transform infrared reflectance spectroscopy and multivariate analysis. The FT-NIR spectra were acquired in duplicate on intact fruits using an integrating sphere (diffuse reflectance). A good prediction was obtained for soluble solids content and titratable acidity. The FT-MIR spectra were acquired for fruit purees using a horizontal ATR cell (Attenuated Total Reflectance). The prediction of sucrose, glucose, fructose and malic and citric acid contents was good.

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace-solid phase microextraction (HS-SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS-SPME-Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS-SPME-GC-MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, [bêta]-cyclocitral, [gamma]-decalactone, 6-methyl-5-hepten-2-one, linalool, [bêta]-ionone, menthone and (E)-hexen-2-al were recognized by HS-SPME-GC-O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.

En: XII International Symposium on Apricot Culture and Decline, Avignon (France). Editor: J.M. Audergon.

In order to elucidate the regulation mechanisms of carotenoid biosynthesis in apricot fruit (Prunus armeniaca), carotenoid content and carotenogenic gene expression were analysed as a function of ethylene production in two colour-contrasted apricot varieties. Fruits from Goldrich (GO) were orange, while Moniqui (MO) fruits were white. Biochemical analysis showed that GO accumulated precursors of the uncoloured carotenoids, phytoene and phytofluene, and the coloured carotenoid, beta-carotene, while Moniqui (MO) fruits only accumulated phytoene and phytofluene but no beta-carotene. Physiological analysis showed that ethylene production was clearly weaker in GO than in MO. Carotenogenic gene expression (Psy-1, Pds, and Zds) and carotenoid accumulation were measured with respect to ethylene production which is initiated in mature green fruits at the onset of the climacteric stage or following exo-ethylene or ethylene-receptor inhibitor (1-MCP) treatments. Results showed (i) systematically stronger expression of carotenogenic genes in white than in orange fruits, even for the Zds gene involved in beta-carotene synthesis that is undetectable in MO fruits, (ii) ethylene-induction of Psy-1 and Pds gene expression and the corresponding product accumulation, (iii) Zds gene expression and beta-carotene production independent of ethylene. The different results obtained at physiological, biochemical, and molecular levels revealed the complex regulation of carotenoid biosynthesis in apricots and led to suggestions regarding some possible ways to regulate it.