Search

In the dataset presented in this article, sixty sugarcane samples were analyzed by eight visible / near infrared spectrometers including seven micro-spectrometers. There is one file per spectrometer with sample name, wavelength, absorbance data [calculated as log(10) (1/Reflectance)], and another file for reference data, in order to assess the potential of the micro spectrometers to predict chemical properties of sugarcane samples and to compare their performance with a LabSpec spectrometer. The Partial Least Square Regression (PLS-R) algorithm was used to build calibration models. This open ac cess dataset could also be used to test new chemometric methods, for training, etc.

Description of the subject. The article deals with the use of near-infrared spectroscopy (NIR) on fresh apples to determine the phenolic compounds and dry matter content in peel and flesh powders.Objectives. The aim is the rapid and non-destructive determination of these nutritional parameters.Method. Two hundred twenty-nine fruits from 20 varieties were analyzed with NIR spectroscopy and reference methods.Results. Great variability of total phenolic compounds (TPC) in peel and flesh powders was observed among varieties. The dry matter (DM) content also differed greatly between peel and flesh. Calibration and validation models showed high coefficients of determination for the TPC content, which were slightly higher for the peel than for the flesh (R² val = 0.91 and 0.84 respectively). For the DM content, high coefficients of determination and ratios of prediction to deviation (RPDs) were also observed (R² val = 0.94, RPD = 4.8 and R² val = 0.94, RPD = 4.9 for the peel and flesh respectively). Conclusions. Calibration and validation models allow quantitative predictions to be made for TPC and DM content. They confirm the potential of NIRS for predicting the polyphenol content and highlight its potential for determining the DM content, a parameter often neglected in research into apple quality., Utilisation de la spectroscopie NIR sur les pommes pour déterminer les teneurs en polyphénols et en matière sèche de la pelure et de la chair des fruitsDescription du sujet. L’article traite de l’utilisation de la spectroscopie proche infrarouge (NIR) sur les pommes pour déterminer les teneurs en polyphénols totaux et en matière sèche des poudres de pelure et de chair du fruit.Objectifs. Le but est de pouvoir déterminer de façon rapide et non destructive ces composés nutritionnels.Méthode. Deux-cent-vingt-neuf fruits provenant de 20 variétés ont été analysés par spectroscopie NIR et avec les méthodes de référence.Résultats. Une grande variabilité du contenu en polyphénols a été observée au sein des variétés. La teneur en matière sèche est également très variable et diffère entre la pelure et la chair. Les modèles de calibration et validation ont montré de hauts coefficients de détermination pour la teneur en polyphénols totaux, légèrement plus élevée pour la pelure que pour la chair (R² val = 0,91 et 0,84 pour la pelure et la chair respectivement). Pour la teneur en matière sèche, de hauts coefficients de détermination et de hauts rapports RPD ont également été observés (R² val = 0,94, RPD = 4,8 et R² val = 0,94, RPD = 4,9 pour la pelure et la chair respectivement).Conclusions. Les modèles développés permettent des prédictions quantitatives des teneurs en polyphénols totaux et en matière sèche. Ces résultats confirment le potentiel de la spectroscopie NIR pour prédire la teneur en polyphénols totaux et met en évidence son potentiel pour déterminer la matière sèche, un paramètre souvent négligé dans la recherche sur la qualité des pommes.

Introduction. For dairy producers who want to transform their milk, the ability of milk to coagulate is an important parameter. It makes it possible to transform milk into cheese. Therefore, it is necessary to understand the coagulation process and the techniques to measure it in order to achieve the best transformation performance. The objective of this review is to describe the milk coagulation process, the factors influencing it and the methods for measuring the coagulation of milk at lab level.Literature. The processing of milk into cheese involves three steps: coagulation, dewatering and refining. Coagulation is a key step which involves the use of rennet and depends on several parameters (pH, calcium content, temperature, etc.). Some milks never coagulate. To measure the coagulation ability of milk and identify different parameters in milk coagulation properties, the Formagraph, the computerized renneting meter and the Optigraph have been developed (reference methods). Equations have been developed using infrared spectrometry to predict the parameters obtained by the reference methods.Conclusions. The milk coagulation mechanism is known. However, the issue of non-coagulating milk persists and represents a real challenge in terms of yield. The use of infrared is a faster alternative to reference methods that measure the coagulation properties of milk, but still requires an improvement in prediction equations., Coagulation du lait : description du processus, facteurs de variation et évaluation des méthodologies (synthèse bibliographique)Introduction. Pour les producteurs laitiers qui souhaitent transformer leur lait, l’aptitude à la coagulation du lait est un paramètre important. Elle permet en effet de transformer le lait en fromage. Dès lors, il convient de bien comprendre son processus et les techniques pour la mesurer afin d’obtenir le meilleur rendement de transformation. L’objectif de cette revue bibliographique est de décrire le procédé de coagulation du lait, les facteurs qui l’influencent et les méthodes pour mesurer la coagulation du lait au niveau du laboratoire. Littérature. Le processus de transformation du lait en fromage implique trois étapes : la coagulation, l’égouttage et le raffinage. La coagulation utilisant la présure est l’étape clé. Elle dépend de nombreux facteurs (pH, teneur en calcium, température, etc.). Certains laits ne coagulent jamais. Pour mesurer l’aptitude du lait à la coagulation, le Formagraph, le Computerized Renneting Meter (CRM) et l’Optigraph furent développés (méthodes de référence). Ils fournissent différents paramètres sur les capacités du lait à coaguler. Des équations ont également été développées grâce à la spectrométrie infrarouge afin de prédire les paramètres obtenus par les méthodes de référence.Conclusions. Bien que le mécanisme de coagulation du lait soit connu, la problématique des laits non coagulants persiste toujours et représente un réel challenge en termes de rendement. L’utilisation de l’infrarouge est une alternative plus rapide aux méthodes de référence pour mesurer les propriétés de coagulation du lait. Toutefois, les équations de prédiction doivent encore être améliorées.

The near-infrared microscope (NIRM) is an instrument that has demonstrated its great ability to detect contaminants not by analyzing a single spectrum but rather by analyzing hundreds or thousands of spectra from individual particles, while at the same time being a non-destructive and easy-to-use technique. It has been used for the detection of meat-and-bone meal (MBM) in compound feeds within the context of the European bovine spongiform encephalopathy (BSE; commonly known as "mad cow disease") crisis. This study describes, for the first time, an application of NIRM instrument standardization using a measurement cell in an inter-laboratory study conducted within the framework of a qualitative determination of animal proteins in compound feeds, based on spectra obtained with eight instruments. The standardization cell was assessed for its ability to produce good optical matching of the instruments and/or to evaluate instrument performance.

For the past few years, research has focused on the application of Near Infrared Spectroscopy (NIR) techniques to analyze the quality of apple varieties. As all fruit quality and nutritional parameters are affected by many factors, to standardize the sampling methods prior to analysis is very important. In this study, the intra-fruit variability of apple varieties in terms of quality parameters (sugar, total polyphenol and vitamin C content) was examined. The adequacy of the protocols usually applied to analyze apple quality (reference analyses of a representative sample of the apple and NIR measurements collected at four points 45° from each other in the equatorial region of the apple) was then investigated. The reference values for the quality parameters showed important intra-fruit variability for all quality parameters analyzed. The results also showed that there was little difference between the mean value at the four points and the mean value of the entire apple. This suggested that a mean value obtained from a representative sample of an apple is enough to assess the variability within the fruit and to estimate, with precision, the content of the quality parameters. The results of NIR spectroscopy showed that measurement at the four target points is suitable for predicting quality parameters precisely. The study concluded that standardized reference analyses should be done on a representative fruit sample of an apple and spectral measurements made at four points 45° from each other in the equatorial region of the apple.

The European Union Reference Laboratory for the detection of animal proteins in feedingstuffs (EURL-AP) has developed an online micrographs collection supporting its network activities within the European Union for the detection of prohibited animal by-products in feed. So far, the only official method for detecting these by-products is light microscopy, which is highly dependent on the skills of a microscopist because it relies on particle recognition. In order to help the microscopist network to achieve high proficiency levels, it was necessary to create an online reference tool based on micrographs and accessible via an Intranet platform. Members of the National Reference Laboratories for animal proteins in feedingstuffs (NRL-AP) and the International Association for Feedingstuff Analysis – Section Feedingstuff Microscopy (IAG) have access to this micrographs collection. This paper describes how the online collection was created and what conditions had to be taken into account in creating such a tool. It also describes how information are periodically updated and managed within the context of the large amount of information included in each micrograph. The need for a robust back-office system as the foundation for all the research activities in this project is also covered, and the evaluation of the use of the online collection is discussed.

The multi-disciplinary and international nature of large European projects requires powerful managerial and communicative tools to ensure the transmission of information to the end-users. One such project is TRACE entitled “Tracing Food Commodities in Europe”. One of its objectives is to provide a communication system dedicated to be the central source of information on food authenticity and traceability in Europe. This paper explores the web tools used and communication vehicles offered to scientists involved in the TRACE project to communicate internally as well as to the public. Two main tools have been built: an Intranet and a public website. The TRACE website can be accessed at http://www.trace.eu.org. A particular emphasis was placed on the efficiency, the relevance and the accessibility of the information, the publicity of the website as well as the use of the collaborative utilities. The rationale of web space design as well as integration of proprietary software solutions are presented. Perspectives on the using of web tools in the research projects are discussed.

A key aspect of the European STRATFEED project on developing and validating analytical methods to detect animal meal in feed was the creation of a samples bank. To manage the 2,500 samples that were stored in the samples bank, another important objective was to build a database and develop an Internet-based data explorer the STRATFEED explorer to enable all laboratories and manufacturers working in the feed sector to make use of the database. The concept developed for the STRATFEED project could be used for samples management in other projects and it is easily adapted to meet a variety of requirements. The STRATFEED explorer can now be run from the public website http://stratfeed.cra.wallonie.be. Each webpage of this application is described in a documentation file aimed at helping the user to explore the database.

The European project FAIR-CT96-5053 concerned the application of the Fourier transform Raman and infrared spectroscopy in food chemistry and quality control. Our research mainly concerned the study of the potential of Raman spectroscopy and the comparison with the results achieved in infrared spectroscopy. The discrimination of virgin olive oil from other edible oils and the detection and quantification of virgin olive oil adulteration have been experimented with this new technique of fast and non-destructive analysis.

Following up on the success of previous chemometric challenges arranged during the annual congress organised by the French Chemometrics Society, the organisation committee decided to repeat the idea for the Chimiometrie 2007 event (http://www.chimiometrie.org/) held in Lyon, France (2930 November) by featuring another dataset on its website. As for the first contest in 2004, this dataset was selected to test the ability of participants to apply regression methods to NIR data. The aim of Challenge 2007 was to perform a calibration model as robust and precise as possible using a data set with only a few reference values available and submitted to different perturbation factors. The committee received nine answers; this paper summarizes the best three approaches, as well as the approach proposed by the organisers.

The multidisciplinary nature, the international partnership and the large amount of information to be managed in an European project such as STRATFEED, require the development of an information management system. Within the framework of this project, the development of the Internet-oriented computer system required three facets: the data and information collection, the database building and the development of different applications. A tool for the dissemination of results (STRATFEED website) with both a public part and a confidential part, a tool for data management (STRATFEED manager), a tool for data queries (STRATFEED explorer) and two tools for decision-making (ARIES Decision Support System CD-Rom release and STRATFEED Decision Support System Internet release) were developed. The modular concept, which relates to the different topics of the project, facilitates the updating and development of a system according to research progress and user needs. The concept developed for this project can be used for any other project and can easily be adapted to meet new requirements. The example of the STRATFEED project can be accessed at: http://stratfeed.cra.wallonie.be

The ban of processed animal proteins (PAPs) in feed for farmed animals led to a significant reduction of the number of bovine spongiform encephalopathy cases. Presently, optical microscopy remains the only reference method for the detection of PAPs to be applied for official control as required by Commission Directive 2003/126/EC. The legislation also foresees that other methods may be applied in addition to classical microscopy, if – for instance – they provide more information about the origin of the animal constituents. Therefore, alternative and complementary techniques were developed as such or in combination. The most promising ones seem to be PCR (Polymerase Chain Reaction), near infrared microscopy and imaging, as well as immunology. Within the framework of a PAP ban regardless of its species origin (total feed ban), most of the studies were mainly focused on the ability of the techniques to detect the presence of PAPs at 0.1% (mass percentage of constituents of animal origin in feed) as indicated as limit of detection in the official method protocol. A possible modification of the legislation requires that the techniques are also able to determine their species origin and to quantify them. The present paper gives a state of the art of the different methods.

Enforcing the ban on meat-and-bone meal in feed for farmed animals, and especially ruminants, is considered an important measure to prevent the spread of bovine spongiform encephalopathy. The authors describe current analytical methods for the detection and identification of animal tissues in feed. In addition, recently approved requirements, such as the ban of intra-species recycling (practice of feeding an animal species with proteins derived from the bodies, or parts of bodies, of the same species) are described. In principle, four different approaches are currently applied, i.e. microscopic analysis, polymerase chain reaction, immunoassay analysis and near infrared spectroscopy or microscopy. The principal performance characteristics of these methods are presented and compared, and their specific advantages and disadvantages described. Special emphasis is also placed on the impact of rendering conditions, particularly high temperatures and on the use of molecular biology techniques.