104 research outputs found

    From the Laboratory to The Vineyard—Evolution of The Measurement of Grape Composition using NIR Spectroscopy towards High-Throughput Analysis

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    Compared to traditional laboratory methods, spectroscopic techniques (e.g., near infrared, hyperspectralimaging)provideanalystswithaninnovativeandimprovedunderstandingofcomplex issuesbydeterminingseveralchemicalcompoundsandmetabolitesatonce,allowingforthecollection of the sample “fingerprint”. These techniques have the potential to deliver high-throughput options for the analysis of the chemical composition of grapes in the laboratory, the vineyard and before or during harvest, to provide better insights of the chemistry, nutrition and physiology of grapes. Faster computers, the development of software and portable easy to use spectrophotometers and data analytical methods allow for the development of innovative applications of these techniques for the analyses of grape composition

    From the Laboratory to The Vineyard—Evolution of The Measurement of Grape Composition using NIR Spectroscopy towards High-Throughput Analysis

    Get PDF
    Compared to traditional laboratory methods, spectroscopic techniques (e.g., near infrared, hyperspectralimaging)provideanalystswithaninnovativeandimprovedunderstandingofcomplex issuesbydeterminingseveralchemicalcompoundsandmetabolitesatonce,allowingforthecollection of the sample “fingerprint”. These techniques have the potential to deliver high-throughput options for the analysis of the chemical composition of grapes in the laboratory, the vineyard and before or during harvest, to provide better insights of the chemistry, nutrition and physiology of grapes. Faster computers, the development of software and portable easy to use spectrophotometers and data analytical methods allow for the development of innovative applications of these techniques for the analyses of grape composition

    APPLICATION OF VIS/NIR SPECTROSCOPYFOR RIPENESS EVALUATIONAND POSTHARVEST QUALITY ANALYSISOF AGRO-FOOD PRODUCTS

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    Agro-food composition at harvest time is one of the most important factors determining the future quality of final products (e.g. wine from grapes and oil from olives). Quality parameters change in function of different product matrix. Measurement of fruits characteristics that impacts on product quality is a requirement for production improvement. Inspection of fruits during ripening is a critical point in all agri-food production chains. This control is usually performed only on small samples that are not always representative of the whole lot. The importance of this monitoring operation is easy to understand, as it determines the economic value of the entire stock. Traditionally, fruits quality evaluation is achieved by a visual and taste assessment of them and evaluation of the traditional quality parameters such as total soluble solids, acidity and texture. The conventional methods to determine fruits quality parameters are time consuming, require preparation of samples, are often expensive, and generally highlight only one or a few aspects of fruits quality. Therefore, there is a strong need in the modern food industry for a simple, rapid, and easy\u2010to\u2010use method for objectively evaluating the quality of fruits. This kind of tool would enable real\u2010time analyses at the receiving station and would allow the preliminary decision\u2010making about grapes during consignment thank to the rapid analysis of various parameters simultaneously. Since food quality is not an individual attribute but it contains a number of inherent characteristics of the food itself, to measure the optical properties of food products has been one of the most studied non-destructive techniques for the simultaneous detection of different quality parameters. In fact, the light reflected from food contains information about constituents in the inner layers of sample and at foodstuff surface also. To achieve objectives of this work, e.g. ripeness evaluation and postharvest quality characteristics of agro-food products, visible near\u2010infrared (vis/NIR) spectroscopy was chosen. In particular, vis/NIR spectroscopy is a rapid and non-destructive technique requiring minimal sample processing before analysis; coupled with chemometric methods, appears to be one of the most powerful analytical tools for studying food products. Chemometrics is an essential part of vis/NIR spectroscopy in food sector. To extract useful information present in the spectra multivariate analysis was carried out. Principal component analysis (PCA) was used for a qualitative analysis of the data and PLS regression analysis as a technique to obtain quantitative prediction of the parameters of interest. The general aim of this work is to study the application of vis/NIR spectroscopy for ripeness evaluation and postharvest quality analysis of agro-food products. In particular this technology was tested to analyse ripening parameters of olives and grapes before to be processed, or to monitor freshness decay of fresh-cut lettuce and apples during long cold storage in controlled atmosphere. Moreover, the feasibility of a simplified handheld and low-cost optical device, based on measurement and processing of diffuse spectral reflectance at a few appropriately selected wavelengths was proposed. This study was focused on identifying the most significant wavelengths able to discriminate in a quick and simple way (i) directly in the field, the blueberries, the grapes, the olives ready to be harvested, (ii) on-line, for the real time monitoring of trend of craft beer fermentation and to estimate qualitative and quantitative parameters or (iii) during shelf life, freshness levels of fresh-cut Lamb\u2019s lettuce (Valerianella locusta Laterr.). The final aim of this work is to realize a simplified modular optical device (with few selected wavelengths) for single sample, non-destructive, and quick prediction of fruit ripeness degree and quality parameters evaluation. The first prototype of simplified optical device was realized for red grapes study and is characterized by the presence of four LEDs emitting at the wavelengths of interest. LED technology was chosen as illumination source of the sample, and allows obvious advantages in term of simplification and cost reduction. The design of the prototype of the simplified optical device was realised with particular attention to versatility and modularity. The possibility to adjust the light source with a specific choice of wavelengths for LEDs, makes it possible to use the same simplified optical device for many different application. This modular design allows an easy adjustment for different objective and for different kind of food sample matrix

    OCM 2013 - Optical Characterization of Materials - conference proceedings

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    The state of the art in optical characterization of materials is advancing rapidly. New insights into the theoretical foundations of this research field have been gained and exciting practical developments have taken place, both driven by novel applications that are constantly emerging. This book presents latest research results in the domain of Characterization of Materials by spectral characteristics of UV (240 nm) to IR (14 µm), multispectral image analysis, X-Ray, polarimetry and microscopy

    OCM 2013 - 1st International Conference on Optical Characterization of Materials: March 6th - 7th, 2013, Karlsruhe, Germany

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    The state of the art in optical characterization of materials is advancing rapidly. New insights into the theoretical foundations of this research field have been gained and exciting practical developments have taken place, both driven by novel applications that are constantly emerging. This book presents latest research results in the domain of Characterization of Materials by spectral characteristics of UV (240 nm) to IR (14 µm), multispectral image analysis, X-Ray, polarimetry and microscopy

    Nondestructive measurement of fruit and vegetable quality

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    We review nondestructive techniques for measuring internal and external quality attributes of fruit and vegetables, such as color, size and shape, flavor, texture, and absence of defects. The different techniques are organized according to their physical measurement principle. We first describe each technique and then list some examples. As many of these techniques rely on mathematical models and particular data processing methods, we discuss these where needed. We pay particular attention to techniques that can be implemented online in grading lines

    SETTING UP OF SIMPLIFIED OPTICAL TOOLS FOR THE EVALUATION OF FRUIT AND VEGETABLES

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    The fruit and vegetable sector met in recent years an important phase of expansion among consumers due to the high nutritive value and convenience of products. This trend is particularly evident for fresh-cut products (fruit and vegetables minimally processed in ready-to-eat packs) due to: (i) their ease of use, and (ii) nutritional properties. Monitoring the quality decay of fruits and vegetables is necessary to control quality parameter, e.g. the freshness level or the ripening degree, during the entire production chain and to ensure quality product for the consumer. The non-destructive technologies are currently used only by research institutions or big companies, due to their cost and complexity of use. Therefore, the sector is interested in new simplified systems for rapid analysis that can be performed along the chain and directly at point of sale with a double objective: to use the information from sensors to better manage the product, and to preserve the consumers' expectations providing additional selection criteria. Objectives of this thesis were the setting up, design and testing of innovative optical simplified devices dedicated to fruit and vegetable products chains. Low-cost and easy-to-use prototypes based on vis/NIR technology and/or multispectral image analysis were presented. In particular, (a) a compact-sized LED technology based device, for the prediction of the main qualitative/ripening parameters of the case studies was realized and tested, and (b) the applicability of multispectral imaging was studied with a view to a simplified optical system for freshness decay assessment. Different kinds of matrix were investigated (white grapes, salad, and apples), with particular attention to fresh-cut products (Valerianella locusta L. salad, Cripps Pink apples). The development stage of the developed system has reached an operative prototype level. An evolution and an engineering of the instrument is still desirable in order to obtain a handheld, user friendly, non-destructive and inexpensive device for farmers utilization in the field. Particular attention must be paid to the modularity concept (i.e. the possibility to adjust light sources with a specific choice of wavelengths for LEDs). This makes it possible to conceive the same simplified optical device for many different applications (i.e. ripeness evaluation, chemicals and physical properties prediction or shelf life analysis) and for different food matrix. Furthermore, an optimization in the calibration for each individual measuring channel is the other significant, since it ensures the reduction of signal to noise ratio for all the measured data. The multispectral imaging study still is at a preliminary level, but sufficient to demonstrate the applicability of this principle as a rapid and non-destructive approach to develop a simplified low-cost optical system for freshness decay assessment. Further work in necessary to develop the research based on this. This thesis demonstrates how the simplification of traditional optical techniques is possible. The proposed methodologies can be replicated and can be the starting point for new research lines regarding innovative technologies for the agro-food sector

    Characterization Of Sala Mango Quality Attributes Via Visible And Near Infrared Spectroscopy Techniques

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    Pada umumnya, penanam buah-buahan dan pihak berkuasa pertanian tempatan semakin menyedari kepentingan untuk memperoleh buah-buahan yang berkualiti tinggi untuk memenuhi permintaan pasaran, khususnya pengguna. Oleh itu, penilaian kualiti buah segar menggunakan teknik optik melalui pengukuran spektroskopi telah dibangunkan untuk menilai dan mengukur kualiti mangga Sala tanpa memusnahkannya. Dalam kajian ini, beberapa pendekatan dengan pengukuran teknik yang berbeza (iaitu: pantulan dan interaksi) telah dilaksanakan dan kecekapannya dibandingkan dengan menggunakan Jaz, QE 65000 dan FieldSpec 3 spektrometer melalui spektrum yang boleh dilihat dan inframerah berserta sistem pengukuran monokromatik yang boleh dilihat untuk mengukur kekerasan, kandungan pepejal larut (SSC) dan keasidan (pH). Berdasarkan prestasi ramalan, MSC merupakan teknik pra-pemprosesan yang terbaik sebelum regresi linear (MLR) untuk mengukur kekerasan mangga menggunakan QE 65000 spektrometer melalui mod pantulan dengan pekali penentuan (R2) dan punca min kuasa dua ralat ramalan (RMSEP) masing-masing pada 0.857 dan 1.005 kgf. Untuk kandungan pepejal larut (SSC), SNV merupakan teknik pra-pemprosesan yang terbaik dengan R2 = 0.882 dan RMSEP = 0.783 ˚Brix menggunakan QE 65000 spektrometer melalui mod interaksi. Fruits‟ growers and local agriculture authorities in general have increasingly realized the importance of acquiring fruits with high quality in order to satisfy the market demands, specifically the consumers. Therefore, quality evaluations of fresh fruits using optical technique through spectroscopy measurement have been developed to non-destructively assess and measure internal quality attributes of Sala mangoes. In this research, several approaches with different technique of measurements (i.e. reflectance and interactance) have been performed and their competences were compared using Jaz, QE 65000 and FieldSpec 3 spectrometers via visible and near infrared spectral as well as visible monochromatic measurement systems for measurement of firmness, soluble solid content (SSC) and acidity (pH). Judging from the prediction performance, MSC was found to be the best preprocessing technique prior to multiple linear regression (MLR) for firmness measurement using QE 65000 spectrometer via reflectance mode with a coefficient of determination (R2) and root mean square error of prediction (RMSEP) at 0.857 and 1.005 kgf , respectively. For soluble solids content (SSC), SNV was found to be the best pre-processing technique with R2 = 0.882 and RMSEP = 0.783˚Brix through measurement using QE 65000 spectrometer via interactance mode
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