Ricard Boqué

Ricard Boqué
Universitat Rovira i Virgili | URV · Faculty of Legal Sciences

Professor of Analytical Chemistry and Chemometrics at Universitat Rovira i Virgili

About

139
Publications
21,033
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4,261
Citations
Citations since 2017
32 Research Items
1955 Citations
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20172018201920202021202220230100200300
20172018201920202021202220230100200300
20172018201920202021202220230100200300

Publications

Publications (139)
Article
In food manufacturing and processing, food matrix complexity usually makes it difficult to detect unwanted subprocesses, which can impact the quality of the final product. In the case of wine alcoholic fermentation, the main process is the conversion of sugars into ethanol and carbon dioxide, but the presence of some unwanted microorganisms could l...
Article
Full-text available
Insects have been a food source for humans for millennia, and they are actively consumed in various parts of the world. This paper aims to ascertain the feasibility of portable near-infrared (NIR) spectroscopy as a reliable and fast candidate for the classification of insect powder samples and the prediction of their major components. Commercially-...
Article
Full-text available
Achieving beer quality and stability remains the main challenge for the brewing industry. Despite all the technologies available, to obtain a high-quality product, it is important to know and control every step of the beer production process. Since the process has an impact on the quality and stability of the final product, it is important to creat...
Article
A new methodology is proposed to describe the evolution of the main chemical compounds of grape must during wine alcoholic fermentation using Attenuated Total Reflectance Mid Infrared (ATR-MIR) spectra in combination with Multivariate Curve Resolution Alternating Least-Squares (MCR-ALS). In addition, we have developed a process control strategy to...
Article
The use of miniaturized NIR spectrometers is spreading over the scientific literature with a particular focus on developing methods as rapid and easy-to-use as possible and following the philosophy of green analytical chemistry. Several applications and studies are typically presented by comparing results obtained with benchtop instrumentation even...
Article
Varietal control to avoid unwanted varietal mixtures is an important objective for the nursery plant industry. In this study, we have developed and analyzed the capabilities of a computer vision system based on deep learning for the control of plant varieties in the nursery plant industry and for evaluating its capabilities. For this purpose, three...
Article
Full-text available
Miniaturised near-infrared (NIR) instruments have been increasingly used in the last few years, and they have become useful tools for many applications on different types of samples. The market already offers a wide variety of these instruments, each one having specific requirements for the correct acquisition of the instrumental signal. This paper...
Article
The aim of this study was to assess how different conditions used on the centrifugation step during olive oil extraction affect its quality by considering the balance of fatty acid alkyl esters (FAAEs) and their precursor alcohols. All the experiments were carried out under real working conditions in a two-phase decanter followed by a vertical cent...
Article
Emmer is a traditional Italian wheat species attracting growing attention for the high-nutritive and dietary value. The growth of emmer consumption and the recent spreading even in areas where production was not traditional pose a risk to biodiversity and to the geographical identities. Thus, the present work aims to develop a non-destructive and r...
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Full-text available
In order to obtain high-quality products and gain a competitive advantage, food producers seek improved manufacturing processes, particularly when physicochemical and sensory properties add significant value to the product [...]
Article
The goal of this article is to guide the reader through the critical points to be faced when monitoring a fermentation following a Process Analytical Technology (PAT) approach. To achieve this purpose Attenuated Total Reflectance – Mid-Infrared (ATR-MIR) spectroscopy coupled to chemometric techniques are proposed. Each of the crucial steps (set up...
Article
Computer vision coupled to deep learning is a promising technique with multiple applications in the industry. In this work, the potential of this technique has been assessed in the classification of two varieties of almond trees (Prunus dulcis), Soleta and Pentacebas. For that, a convolutional neural network named VGG16 was used. The most appropria...
Article
Full-text available
The miniaturisation of analytical devices, reduction of analytical data acquisition time, or the reduction of waste generation throughout the analytical process are important requirements of modern analytical chemistry, and in particular of green analytical chemistry. Green analytical chemistry has fostered the development of a new generation of mi...
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Daily consumption of caffeine in coffee, tea, chocolate, cocoa, and soft drinks has gained wide and plentiful public and scientific attention over the past few decades. The concentration of caffeine in vivo is a crucial indicator of some disorders—for example, kidney malfunction, heart disease, increase of blood pressure and alertness—and can cause...
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Using trained panelists to evaluate sensory attributes is unfeasible when many samples must be evaluated, such as in quality control or breeding programs. Near-infrared spectroscopy (NIRS) is a rapid inexpensive method often used in food quality evaluation. We assessed the feasibility of using NIRS to estimate sweetness, fiber perception, and off-f...
Article
There is a growing need of measurement technologies that can be used close to the sample source and optical spectroscopy is an excellent example of this genre of technology: from the lab to the field. This study investigates the possibility to quantify the major components and to detect the presence or absence of lactose in commercial milks with AT...
Article
Despite the winemaker’s efforts, deviations such as bacterial spoilage can occur during wine alcoholic fermentation resulting in economic losses and low quality wines. When a deviation is suspected, samples are usually sent to an oenological laboratory for the off-line analysis of specific quality control parameters. The use of ATR-MIR as a fast an...
Article
Background: The use of healthy olives and their good management along the production process are necessary to obtain the best quality virgin olive oils. One of the parameters related to the health of the olives is the content of fatty acid alkyl esters. Since these come from the esterification of C16 and C18 free fatty acids with short chain alcoh...
Article
This study aimed to develop a fast analytical method, combining near infrared reflectance spectroscopy and multivariate analysis, for detection and quantification of pork meat in other meat samples. A total of 5952 mixture samples from 39 types of meat were prepared in triplicate, with the inclusion of pork at 0%, 1%, 5%, 10%, 30%, 50%, 70%, 90% an...
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Full-text available
The emergence of new almond tree (Prunus dulcis) varieties with agricultural interest is forcing the nursery plant industry to establish quality systems to keep varietal purity in the production stage. The aim of this study is to assess the capability of near-infrared spectroscopy (NIRS) to classify different Prunus dulcis varieties as an alternati...
Article
The synthesis of 2-hydroxybenzoyl pyridopyrimidines (M1-M4) has been carried out with 3-formyl chrome derivatives and 6-amino-1-methyluracil to employ them as anion chemosensors. Pyridopyrimidine-based compounds were studied as colorimetric and fluorescent receptors for anion sensing. The observations with naked eye and the data obtained by UV–visi...
Article
Wine production processes still rely on post-production evaluation and off-site laboratory analyses to ensure the quality of the final product. Here we propose an at-line methodology that combines a portable ATR-MIR spectrometer and multivariate analysis to control the alcoholic fermentation process and to detect wine fermentation problems. In tota...
Article
Full-text available
Urea is added as an adulterant to give milk whiteness and increase its consistency for improving the solid not fat percentage, but the excessive amount of urea in milk causes overburden and kidney damages. Here, an innovative sensitive methodology based on near‐infrared spectroscopy coupled with multivariate analysis has been proposed for the robus...
Article
A portable FTIR‐ATR spectrometer was used to monitor small‐scale must fermentations (microvinifications) with the aims to describe the process and to early detect problematic fermentations. Twenty fermentations at normal operation conditions (NOC) and three fermentations that were intentionally deviated from NOC (yeast assimilable nitrogen deficien...
Article
Near-infrared spectroscopy (NIRS) can be a faster and more economical alternative to traditional methods for screening varietal mixtures of nursery plants during the propagation process to ensure varietal purity and to avoid errors in the dispatch batches. The global objective of this work was to develop and optimize a NIR spectral collection metho...
Chapter
With the growing availability of high throughput methodologies for food characterization and analysis, more and more data are being collected on food products that can be used for the authentication of their quality. In this context, the availability of different multi-block strategies, each with its own peculiarities and providing specific details...
Article
‘Calçots’, the immature floral stems of second-year onion resprouts, are an economically important traditional crop in Catalonia (Spain). Classical approaches to evaluating the chemical properties of ‘calçots’ are time consuming and expensive; near-infrared spectroscopy (NIRS) may be faster and cheaper. We used NIRS to develop partial least square...
Article
Ethanol, due to its high octane rating of 108, is often added as adulterant to premium 91 gasoline fuels to boost up their octane ratings to 96 or more but it does not provide the same power to engine as that of super-premium 96 gasoline fuels. In this study, a sensitive near infrared spectroscopy (NIRS) coupled with chemometrics was proposed for a...
Article
New NIR spectroscopy combined with multivariate analysis for detection and quantification of camel milk adulteration with goat milk was investigated. Camel milk samples were collected from Aldhahira and Sharqia regions of Sultanate of Oman and were measured using NIR spectroscopy in absorption mode in the wavelength range from 700-2500 nm, at 2 cm⁻...
Chapter
Sensory analysis allows the description of profiles, the determination and quantification of the organoleptic characteristics of a product, and the monitoring of quality control. This chapter describes the state of art and the new trends that are emerging in the instrumental sensory analysis area. Nowadays, one of the most important challenges in f...
Chapter
Fused data or sensors are treated as a single response derived from a collection of nonspecific measurements done on the same sample with subsequent mathematical analysis of different outputs. There are several types of data fusion methods reported in the literature: low-level fusion, mid-level fusion, and high-level fusion. In this chapter, we dis...
Article
Full-text available
Red band needle blight caused by Dothistroma septosporum and D. pini, and brown spot needle blight caused by Lecanosticta acicola provoke severe and premature defoliation in Pinus, and subsequent reduction of photosynthetic surfaces, vitality, and growth in young and adult trees. The recurrent damage results in branch and tree death. Until recently...
Article
Headspace mass-spectrometry (HS-MS), mid infrared (MIR) and UV-vis spectroscopy were used to authenticate whisky samples from different origins and ways of production ((Irish, Spanish, Bourbon, Tennessee Whisky and Scotch). The collected spectra were processed with partial least-squares discriminant analysis (PLS-DA) to build the classification mod...
Article
Headspace-Mass Spectrometry (HS-MS), Fourier Transform Mid-Infrared spectroscopy (FT-MIR) and UV-Visible spectrophotometry (UV-vis) instrumental responses have been combined to predict virgin olive oil sensory descriptors. 343 olive oil samples analyzed during four consecutive harvests (2010-2014) were used to build multivariate calibration models...
Article
Three instrumental techniques, headspace-mass spectrometry (HS-MS), mid-infrared spectroscopy (MIR) and UV-visible spectrophotometry (UV-vis), have been combined to classify virgin olive oil samples based on the presence or absence of sensory defects. The reference sensory values were provided by an official taste panel. Different data fusion strat...
Chapter
Parallel Factor Analysis (PARAFAC) is a popular multiway decomposition method for analytical data. This chapter introduces the PARAFAC model and the concepts of bilinearity and trilinearity of second-order data. The ALS algorithm to calculate the model, and the use of PARAFAC for calibration are also described. Practical aspects such as data prepro...
Article
Full-text available
A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wave...
Article
A Near Infrared (NIR) spectroscopic method combined with multivariate calibration was developed for the determination of the amount of sucrose in date fruits growing in the Sultanate of Oman. In this study two groups of samples were used: one group of 48 sucrose standard solutions in the concentration range from 0.01% to 50% (w/v) and another group...
Article
The ever increasing interest of consumers for safety, authenticity and quality of food commodities has driven the attention towards the analytical techniques used for analyzing these commodities. In recent years, rapid and reliable sensor, spectroscopic and chromatographic techniques have emerged that, together with multivariate and multiway chemom...
Article
A methodology was developed to distinguish transgenic from non-transgenic soybean oils samples by using FT–MIR spectroscopy coupled with discrimination techniques, including Soft Independent Modeling of Class Analogies (SIMCA), Support Vector Machine–Discriminant Analysis (SVM-DA) and Partial Least Squares–Discriminant Analysis (PLS-DA). The discri...
Article
The problem of the distinguishing soil is crucial for its preparation for cultivation in a country that exports several agricultural commodities. The system of soil classification adopted in Brazil is based on chemical parameters, physical and morphological changes. This system shows disadvantages because many analyzes are time-consuming especially...
Article
Full-text available
Norfloxacin (NOR) is widely used in human and animal therapy, and its main route of excretion is urine. Several methods were employed to determine NOR in tablets or biological samples. Generally, in biological matrices it is performed a dilution and/or spiking of the sample. In the literature, there are some references that focus specifically the m...
Chapter
Calibration based on a classical univariate regression requires completely selective measurements. Therefore, predictions may be biased severely when this requirement is not fulfilled. Multivariate regression is presented as a means to overcome these limitations. Three different approaches to multivariate calibration are presented: the classical le...
Chapter
This chapter presents the most widely applied and, probably, satisfactory multivariate regression method used nowadays: partial least squares (PLS). Graphical explanations of many concepts are given to complement the more formal mathematical background. Several approaches to solving current problems are suggested. The development of a satisfactory...
Article
This research work describes two studies for the classification and characterization of edible oils and its quality parameters through Fourier transform mid infrared spectroscopy (FT-mid-IR) together with chemometric methods. The discrimination of canola, sunflower, corn and soybean oils was investigated using SVM-DA, SIMCA and PLS-DA. Using FT-mid...
Article
An objective method based on partial least-squares discriminant analysis (PLS-DA) was used to assign an oil lump collected on the coastline to a suspected source. The approach is an add-on to current US and European oil fingerprinting standard procedures that are based on lengthy and rather subjective visual comparison of chromatograms. The procedu...
Article
Near infrared (NIR) spectroscopy and multivariate classification were applied to discriminate soybean oil samples into non-transgenic and transgenic. Principal Component Analysis (PCA) was applied to extract relevant features from the spectral data and to remove the anomalous samples. The best results were obtained when with Support Vectors Machine...
Article
Full-text available
Beer samples of the same brand and commercialized as a same product, but brewed in four different factories were analyzed with three techniques, an MS e-nose, a mid-IR optical-tongue and a UV-visible, to see if the factories show differences and to find out if the differences found could be attributed to different sensory properties. The data from...
Article
A novel method for establishing multivariate specifications of food commodities is proposed. The specifications are established for discriminant partial least squares (DPLS) by setting limits on the predictions of the DPLS model together with Hotelling T(2) and square error of prediction (SPE). These limits can be tuned depending on whether type I...
Article
Full-text available
An electronic nose based on coupling of headspace (HS) with a mass spectrometer (MS) has been used in this study to classify and characterize a series of beers according to their production site and chemical composition. With this objective, we analyzed 67 beers of the same brand and preparation process but produced in different factories. The samp...
Article
In this work, the ability of an electronic tongue based on Fourier-Transform Mid Infrared (FT-MIR) spectroscopy as a gustative sensor is assessed by emulating the responses of a tasting panel for the gustative mouthfeel “tannin amount”. The FT-MIR spectra were modeled against the sensory responses evaluated in 37 red wines by means of partial least...
Article
The reject option plays an important role in the classification of microarray data. In this work, a reject option is implemented in the probabilistic discriminant partial least squares (p-DPLS) method in order to reject to classify both outliers and ambiguous samples. Microarray data are highly susceptible to present outliers because of the many st...
Article
This work describes multi-classification based on binary probabilistic discriminant partial least squares (p-DPLS) models, developed with the strategy one-against-one and the principle of winner-takes-all. The multi-classification problem is split into binary classification problems with p-DPLS models. The results of these models are combined to ob...
Article
Full-text available
A method to verify the feasibility of the calibration transfer technique in HS-MS wine analysis is proposed. PLS multivariate calibration models, whose elaboration and prediction quality are fully discussed, have been built for the quantitative determination of three of the most common volatiles found in wine aroma: ethyl hexanoate (EH), isoamyl ac...
Article
A variety of analytical techniques generate a matrix of instrumental responses for each analyzed sample. A large number of multivariate (multiway) methods of analysis can provide qualitative and quantitative information from such data. In this section we discuss those methods that are based on solving an eigenvalue problem, basically rank annihilat...
Article
Microarrays are used to simultaneously determine the expressions of thousands of genes. An important application of microarrays is in the classification of samples into classes of interest (e.g. either healthy cells or tumour cells). Discriminant partial least squares (DPLS) has often been used for this purpose. In this paper, we describe an improv...
Article
An analytical result should be expressed as x+/-U, where x is the experimental result obtained for a given variable and U is its uncertainty. This uncertainty is rarely taken into account in supervised classification. In this paper, we propose to include the information about the uncertainty of the experimental results to compute the reliability of...
Article
A classification decision must include the degree of confidence in that decision. We have modified the binary classification method Discriminant Partial Least Squares (DPLS) to provide the reliability of the classification of an unknown object. This method, called Probabilistic Discriminant Partial Least Squares (p-DPLS), integrates DPLS, density m...
Article
The concept of the limit of detection (LOD) has been, and still is, one of the most controversial in analytical chemistry. The multiple definitions and calculation methods proposed have contributed to this situation. Although in the last years, several international organizations, such as ISO or IUPAC, have tried to reach a consensus in their defin...
Article
The limit of detection (LOD) is usually defined as the lowest quantity or concentration of a component that can be reliably detected with a given analytical method. Intuitively, the LOD would be the lowest concentration obtained from the measurement of a sample (containing the component) that we would be able to discriminate from the concentration...
Chapter
A variety of analytical techniques generate a matrix of instrumental responses for each analyzed sample. A large number of multivariate (multiway) methods of analysis can provide qualitative and quantitative information from such data. In this section we discuss those methods that are based on solving an eigenvalue problem, basically rank annihilat...
Chapter
This is the first book for atomic spectroscopists to present the basic principles of experimental designs, optimization and multivariate regression. Multivariate regression is a valuable statistical method for handling complex problems (such as spectral and chemical interferences) which arise during atomic spectrometry. However, the technique is un...
Chapter
This is the first book for atomic spectroscopists to present the basic principles of experimental designs, optimization and multivariate regression. Multivariate regression is a valuable statistical method for handling complex problems (such as spectral and chemical interferences) which arise during atomic spectrometry. However, the technique is un...
Article
Estimating uncertainty has become one of the most important metrological concepts in analytical science over the last 15 years to such an extent that some authors consider a result useless or invalid unless it is accompanied with an uncertainty statement. This article describes how to estimate uncertainty in chromatographic analysis and how laborat...
Article
We evaluate the uncertainty in organic elemental analysis of C, H, N, and S. We use data from six proficiency tests (PTs), in which some 35 Spanish laboratories participated. The uncertainty of the technique is estimated from the relative within-laboratory and between-laboratory variances for pure substances and samples with complex matrices (soil,...
Article
Full-text available
This paper presents a new method for computing the probability of correct classification for the k-Nearest Neighbours (kNN) method. The method uses bootstrap to provide the posterior probability which a new object is classified with. This is a measure of the reliability of the classification; it increases as the test object is closer to the trainin...
Article
The assessment of accuracy, which involves the estimation of precision and the determination of trueness, refers to the process of evaluating whether the results provided by analytical methods are close to accepted reference values. The different references available in chromatographic analysis and useful guidelines to perform such a comparison are...
Article
The different calibration approaches that are used for measuring instruments are discussed. Calibration refers to the process of determining the relation between the output of a measuring instrument and the value of the input quantity or property. Univariate or a multivariate calibration is performed depending on the univariate or multivariate char...
Article
Full-text available
Most heavy metals are present in trace concentrations in many matrices whereas concomitants are, generally, several orders of magnitude higher. Thus, when Sb was determined in water samples by electrothermal atomic absorption spectrometry (ETAAS), typical major concomitant ions Ca2+, Fe3+, Na+, Mg2+, Cl−, PO43− and SO42− induced displacement, deple...
Article
Non-negative matrix factorization (NMF) is a technique that decomposes multivariate data into a smaller number of basis functions and encodings using non-negative constraints. These constraints make that only positive solutions can be obtained and thus this method provides a more realistic approximation to the original data than other factorization...
Article
This paper gives an introduction to multivariate calibration from a chemometrics perspective and reviews the various proposals to generalize the well-established univariate methodology to the multivariate domain. Univariate calibration leads to relatively simple models with a sound statistical underpinning The associated uncertainty estimation and...
Article
This paper shows the potential of excitation-emission fluorescence spectroscopy (EEFS) and three-way methods of analysis [parallel factor analysis (PARAFAC) and multiway partial least-squares (N-PLS) regression] as a complementary technique for olive oil characterization. The fluorescence excitation-emission matrices of a set of Spanish extra virgi...
Article
The production area of the Protected Denomination of Origin (P.D.O.) “Siurana� olive oils can be divided into two regions: “Montsant� and “Camp de Tarragona�, with different orography, soil characteristics and climatic conditions. As a result of these differences, the oils have variable stability. Here we show that excitation-emission f...
Article
Full-text available
We describe how to calculate uncertainty in the determination of aflatoxin B(1) in nuts and maize using an HPLC method with prederivatisation with trifluoroacetic acid and fluorescence detection. The uncertainty is easily calculated using the information obtained from the participation in several proficiency tests. All the sources of uncertainty ar...