15 December 2010

Food

 

R. Paolesse, C. Di Natale, A. D’Amico, E. Martinelli, A. Alimelli, M.G. D’Egidio, G. Aureli, C. Fanelli, A. Ricelli; Detection of fungal contamination of cereal grain samples by an electronic nose, Sensors and Actuators B 119 2006 425-430

Fungal growth on cereal grains decreases their nutritional value and constitutes health hazards, probably, because of the production of toxic metabolites (mycotoxins). Therefore, attempts are coming out to detect and quantify the degree of fungal infection at the early stage of mold infection. One of the most promising techniques is the analysis of volatile compounds in the headspace gas surrounding the samples.

The aim of this work was to study the possibility of the application of electronic nose for an early detection of volatile compounds in infected samples and to discriminate between non-infected and infected samples with two different species of fungi (Penicillium chrysogenum and Fusariumverticillioides). Moreover, GC–MS analysis of the headspaces of the same samples confirmed that electronic nose as a powerful tool is able to provide satisfactory indications about the rate of contamination.

 

 F. Sinesio, C. Di Natale, G. Quaglia, F. Bucarelli, E. Moneta, A. Macagnano, R. Paolesse, A. D’Amico; Use of electronic nose and trained sensory panel in the evaluation of tomato quality, Journal of the Science of Food and Agriculture 80 2000 63-71

In this paper the performances of an electronic nose based on metalloporphyrin-coated quartz microbalance sensors and of an experienced panel of seven human assessors in the evaluation of gases derived from degradation reactions in tomatoes are presented and discussed. The performances are measured in terms of the capability of both systems to distinguish between samples of different quality coming from conventional and organic production systems. The study deals with the application of pattern recognition techniques based on either multivariate statistical methods (PCA, GPA) or artificial neural networks using a self-organising map (SOM). The response pattern of the sensor array and the sensory data are analysed and compared using these methods. Similarities in the classification of the data by electronic nose and human sensory profiling are found.

 

 

A.Z. Berna, S. Buysens, C. Di Natale, I.U. Grin, J. Lammertyn, B.M. Nicolai; Relating sensory analysis with electronic nose and headspace fingerprint MS for tomato aroma profiling, Postharvest Biology and Technology 36 2005 143-155

This paper relates aroma compounds measured by means of an electronic nose and headspace fingerprint mass spectrometry (HFMS) to sensory analysis for tomato aroma evaluation. Eight tomato cultivars harvested at the red-ripe stage of maturity were selected and assessed on days 4, 7, 10 and 14 after harvest. Descriptive sensory analysis was performed by eight trained panellists. For instrumental analysis a quartz microbalance electronic nose (QMBE-nose), headspace fingerprint mass spectrometry and gas chromatography–mass spectrometry (GC–MS) as reference techniques were employed. Initially, canonical discriminant analysis (CDA) was performed separately on the instrumental and sensory data sets to explore the structure of each data set. The results showed that the sensory data contained information related to the cultivar but not to shelf life as was found with the instruments. Sensors of the QMBE-nose, GC aroma values and signals of the HFMS, were further studied to investigate their relationship with the sensory profile of tomato cultivars using generalized procrustes analysis (GPA). The results demonstrate the potential of the electronic nose and the headspace fingerprint MS to complement routine sensory analysis of tomatoes.

 

 

A.Z. Berna, J. Lammertyn, S. Buysens, C. Di Natale, B.M. Nicolai; Mapping consumer liking of tomatoes with fast aroma profiling techniques, Postharvest Biology And Technology 38 2005 115-127

This paper focuses on relating consumer preference data of tomato cultivars to novel aroma profiling methods as a basis for fast screening of new cultivars with specific aroma characteristics. Cluster analysis was carried out to segment the 54 Flemish consumers into homogeneous groups. The analysis identified four consumer segments with different preference patterns. Internal preference mapping was then used to derive a preference space of tomatoes cultivars based on the overall liking by the consumer segments.

Tomatoaroma profiles identified with gas chromatography–mass spectrometry (GC–MS), headspace fingerprint mass spectrometry and the electronic nose (E-nose) were regressed separately on the preference map to identify the most important aroma characteristics determining consumer acceptance. Although the consumers were asked to evaluate general acceptance of the tomato samples which encompasses not only aroma but also taste and texture, a high correlation between aroma profile and acceptance was obtained. The results demonstrate the value of internal preference mapping to integrate two data sets in a multidimensional map allowing the elucidation of consumer liking of tomatoes in relation to the aroma.

 

 

 Berna, J. Lammertyn, S. Saevels, B. Nicolai, I Grun, S. De Poortere, S. Buysens, C. Di Natale; Tomato quality evaluation using electronic nose systems to complement sensory analysis, Acta Horticultura 682 2005 1021 - 1028

This paper compares and relates electronic nose systems and sensory analysis for tomato aroma evaluation. Eight tomato cultivars were selected and assessed on days 4, 7 and 14 after harvest. They were harvested at the red-ripe stage of maturity. Descriptive sensory analysis was performed by seven trained panellists. For instrumental analysis a quartz microbalance electronic nose (QMBE-nose) and a mass spectrometry based electronic nose (MSE-nose) were used. Initially, principal component analysis was performed separately on the instrumental and sensory data sets to explore the structure of each data set. Sensors and signals of the QMBE-nose and MSE-nose, respectively, were then further studied to investigate their relation with the sensory profile of tomato cultivars, using generalized procrustes analysis. The results show the potential of both electronic nose systems to complement routine sensory analysis of tomatoes.

 

 

 A.Z. Berna, J. Lammertyn, S. Saevels, C. Di Natale, B. Nicolai; Electronic nose systems to study shelf life and cultivar effect on tomato aroma profile, Sensors and Actuators B 97 2004 324-333

The performance of a quartz microbalance based electronic nose (E-nose) and a mass spectrometry based electronic nose (MSE-nose) for tomato aroma profiling has been evaluated. Solid phase micro-extraction (SPME) headspace sampling combined with gas chromatography (GC) has been used as a reference method. In the first experiment, the changes in tomato aroma profiles of two different cultivars have been monitored during shelf life (Days 1, 8, 12 and 19). The score plot of the principal component analysis (PCA) for the E-nose measurements shows a slight shift along the first principal component corresponding to an increasing number of days of shelf life. However, the tomato aroma profiles measured on Days 1 and 8 could not be discriminated by the E-nose. In contrast, MSE-nose score plots indicated an evident change in aroma profile with shelf life. The loading plots of the PCA reveals that mainly three discriminant mass to charge ratios (m/z = 93, 43 and 57) are responsible of the observed shelf life effect in both cultivars. These fragments indicate that β-phellandrene, 6-methyl-5-hepten-2-one, 1-nitropentane and 2-methylbutanol undergo important concentration changes during shelf life of tomatoes. In the second experiment, the aroma differences between cultivars were analysed by means of the electronic nose systems. A clear distinction between cultivars based on MSE-nose measurements is obtained; however, based on E-nose measurements it is difficult to discriminate between tomato varieties in two dimensions. 

 

C. Di Natale, R. Paolesse, A. Macagnano, A. Mantini, A. D’Amico, A. Legin, L. Lvova, A. Rudnitskaya, Y. Vlasov; Electronic nose and electronic tongue integration for improved classification of clinical and food samples, Sensors and Actuators B 64 2000 15-21

A combined approach based on a multisensor system, to get chemical information from liquid samples through the analysis of the solution and its head space is illustrated and commented. Sensors operating in liquid (electronic tongue) and in the head space (electronic nose) are based on the same sensitive materials: the metalloporphyrins. This gives the opportunity of a certain uniformity of interaction putting in evidence the differences between the solution and its related volatile part. The combined system has been tested in two different experiments in the fields of clinical and food analysis, respectively. Results have shown a net increase of information when the combined systems are used. The sensor fusion procedure has been optimised in order to achieve the best results.

 

 

 C. Di Natale, R. Paolesse, A. Macagnano, A. Mantini, A. D’Amico, M. Ubigli, A. Legin, L. Lvova, A. Rudnitskaya, Yu. Vlasov; Application of a combined artificial olfaction and taste system to the quantification of relevant compounds in red wine, Sensors and Actuators B 69 2000 342-347

The combined application of an electronic nose and an electronic tongue to a number of samples of red wine having the same denomination, produced in the same year but from different vineyards, is illustrated and discussed. Artificial sense data have been compared with the analytical chemistry analysis performed with ordinary methods.

The data reveal, first of all, a net distinction between electronic nose and electronic tongue, confirming the hypotheses that both the systems offer independent information on the samples. A certain correlation with some of the analytical indicators has also been found and a neural network regression model has been assessed for the qualitative determination of some of them.

 

C. Di Natale, F. Davide, A. D’Amico, P. Nelli, S. Groppelli, G. Sberveglieri; An Electronic Nose for the recognition of the vineyard of a red wine, Sensors and Actuators B 33 1996 83-88

Sensor arrays have been tentatively utilized in the past as tools for the odours characterisation of particular classes of foods and beverages. In this paper a technique aiming to discriminate among similar wines is described. A sensor array of metal-oxide based gas sensors was employed for the recognition of two wines, having the same denomination (Groppello red wine) but coming from different vineyards. The performance of the array was compared with that of the standard chemical analytical approach adopted by the wines authority.

 

 

·C. Di Natale, A. Macagnano, R. Paolesse, A. D'Amico; Artificial olfaction systems: principles and applications to food analysis, Biotechnology, Agronomy, Society and Environment 5 2001 139-165

Among the numerous applications of electronic nose technology, the analysis of foodstuff is one of the most promising and also the most travelled road towards industrial applications. On the other hands, since human senses are strongly involved in the interaction with foods the analysis of food provides an excellent field to compare the performances of natural and artificial olfaction systems. The electronic nose, being non-destructive and, in principle, directly correlated with the consumerperceptions, is a good candidate to develop quality evaluation tools for quality assessment. In this paper, the application of electronic nose to the evaluation of quality of foods is discussed. As selected example, the measure of quality of fruit is outlined. The experiments described have been performed with an electronic nose developed by the authors and of which a description is also given.

 

C. Di Natale, A. Macagnano, S. Nardis, R. Paolesse, C. Falconi, P. Siciliano, R. Rella, A. Taurino, A. D’Amico; Comparison and integration of arrays of quartz resonators and metal-oxide semiconductor chemoresistors in the quality evaluation of olive oil, Sensors and Actuators B 78 2001 303-309

Olive oil analysis is considered as a promising application of electronic noses. In this paper, two electronic noses, based on different sensor technologies (quartz resonators and metal-oxides chemoresistors) are applied to the measure of samples of olive oils of different qualities and values. Among them, samples of oil produced from organically farmed olives have also been measured. While both the sensor systems provided very similar images for the commercial oils defining a sort of quality growing direction in their principal component analysis score plots, the organically farmed product has been differently interpreted by the two arrays.

Merging of data, both at high and low abstraction level, shown that the co-operation of the two sensor arrays identified the organically farmed product different from the commercial samples.

Details about the single sensors behavior, and the option of sensors data fusion will be illustrated and discussed.

 

 

·Macagnano, M. Careche, A. Herrero, R. Paolesse, E, :Martinelli, G. Pennazza, P. Carmona, A. D’Amico, C. Di Natale; A model to predict fish quality from instrumental features, Sensors and Actuators B 111 2005 293-298

Sensorial evaluation of fishes, using a well-defined scheme including several qualitative attributes, can give a reliable quantitative evaluation of freshness (quality index method, QIM). The introduction of artificial instruments, mimicking human senses, seems a promising approach to obtain a comparable judgment with trained panels one. The outputs of colour, texture and electronic nose measurements can be compared and combined by data fusion, to construct an artificial quality index (AQI), describing the quality of fish at least as well as the QIM predicted.

In this paper, the application of such approach to build a fish freshness indicator of sardine fishes is illustrated.

 

 

·G. Olafsdottir, P. Nesvadba, C. Di Natale, M. Careche, J. Oehlenschlager, S.V. Tryggvadottir, R. Schubring, M. Kroeger, K. Heia, M. Esaiassen, A. Macagnano, B. Jorgensen; Multisensor for fish quality determination, Trends in Food Science and Technology 15 2004 86-93

The European fish industry is still reluctant to implement methods other than sensory to monitor freshness and quality of fish products, although general concensus exists about the importance of various quality attributes and the need for methods to monitor quality. The objective of the project FAIR CT98-4076 (MUSTEC) was to evaluate several physico-chemical techniques and to integrate their outputs into a more robust estimate of the freshness quality of fish. The techniques used for this multisensor approach were based on visible light spectroscopy, electrical properties, image analysis, colour, electronic noses and texture. Combining the outputs of the instrumental techniques and calibrating them with sensory scores of Quality Index Method (QIM) for attributes like appearance, smell and texture, gives an Artificial Quality Index (AQI) that can be as accurate and precise as the QIM sensory score. The outcome provides a basis for the construction and industrial exploitation of multi-sensor-devices for defining the quality of fish.

 

 

·C. Di Natale, G. Olafsdottir, S. Einarsson, E. Martinelli, R. Paolesse, A. D’Amico; Comparison and integration of different electronic noses for freshness evaluation of cod fish fillets, Sensors and Actuators B 77 2001 572-578

Quality of fruit is traditionally associated with the physical characteristics, such as surface colour, shape, and firmness. Although, it is well known that the aroma is also associated with the ripening processes, this feature never resulted in any practical instrumentation due to the complexity of the aroma analysis. Over the past years, electronic nose technology opened the possibility to exploit information on aroma to assess fruit ripening stage, and more generally, fruit quality.

In order to match the instrumental analysis with the consumer requirements, a sensorial profile of the fruit is necessary. From the point of view of sensory analysis, fruits have not been extensively studied and a complete and detailed description of the aroma components is not well established.

In this paper, an electronic nose and a sensory panel are considered together in order to study the sensorial properties of a number of peaches and nectarines. Fruits were divided into four classes; each composed of several cultivars. The research is aimed at evaluating the sensorial features typical of each class.

This work represents a first attempt toward the definition of a sensorial profile for these fruits, and it can be considered a further proof of the fruitful interactions between natural olfaction and electronic nose.

 

 

 

·                    M. Santonico, P. Pittia, G. Pennazza, E. Martinelli, M. Bernabei, R. Paolesse, A. D’Amico, D. Compagnone, C. Di Natale; Study of the aroma of artificially flavoured custards by chemical sensor array fingerprinting, Sensors and Actuators B 133 2008 345-351

It is generally known that the chemical analysis of the volatile compounds of foods is not adequate to describe the complexity of flavours; as a consequence, sensory analysis is the fundamental methodology to determine quality and acceptability of food products. Nonetheless, instrumental estimations of human reactions to food are still highly demanded. To this regard the synthetic and qualitative representation of data originated by multivariate instruments has gained importance in the last years. In particular, fingerprints from chemical sensor arrays have been a subject of investigation aimed at developing instrumental measurements of human olfactory perceptions.

In this paper, a study case on the application of a sensor array aimed at appraising the flavour properties of custard desserts seasoned with strawberry aroma is presented. These studies were intended to determine the effects of some key ingredients (milk fat content and sugar type) to the aroma and to the aroma temporal decay under controlled storage. Sensor data have been compared and complemented with those provided by gas-chromatography and sensory analysis. The results indicate that custard headspace fingerprinting can obviously recognize the addition of artificial flavours, and, more noteworthy, discriminate among fat milk content and sugar types used to prepare the samples. Furthermore, composition was also found to affect the temporal evolution of aroma evidencing distinct paths in a principal component analysis (PCA) score plot for samples prepared with different ingredients.

 

 

 

·                    C. Di Natale, D. Filippini, G. Pennazza, M. Santonico, R. Paolesse, A. Bellincontro, F. Mencarelli, A. D’Amico, I. Lundstrom; Sorting of apricots with computer screen photoassisted spectral reflectance analysis and electronic nose, Sensors and Actuators B 119 2006 70-77

Optical properties and aroma have been indicated as sources of information for the analysis of quality of fruits. Optical properties can be measured with several experimental arrangements and equipments that are often complex with result difficult to interpret. In recent years, a number of suggestions arose in the sensor community proposing the use of conventional computer peripheral devices as analytical instruments. Among them the combination of a computer screen and a webcam was demonstrated to be suitable to measure optical properties of materials. In this paper this arrangement is utilized to characterize the reflectance of apricot fruits that underwent different post-harvest treatment and mechanical damages. Optical measurements were complemented by aroma analysis with an electronic nose. The response of fruits to treatments was also monitored measuring CO₂ (indicator of respiration) and ethylene (indicator of ripening); both these parameters are known to be influenced by post-harvest treatment and mechanical damages. Results show that a computer screen–webcam combination and an electronic nose are both sensitive to mechanical damages of fruits devising their use, after due optimization, for routine fruit sorting.

 

 

·                    S. Saevels, J. Lammertin, A.Z. Berna, E.A. Veraverbeke, C. Di Natale, B.M. Nicolai; An electronic nose and a mass spectrometric based electronic nose for assessing apple quality during shelf life, Postharvest Biology And Technology 31 2004 9-19

The potential of the electronic nose (E-nose) and the mass spectrometer-based E-nose (MSE-nose) to monitor changes in apple fruit volatiles during shelf life was studied. These techniques were compared with a traditional technique to measure volatiles, gas chromatography combined with mass spectrometry (GC/MS). Apples were stored for 8 months at three different storage conditions and the volatile profile changes were followed subsequently over a period of 15 days. Analysis of the score plot of the principal components analysis for the E-nose measurements showed no storage history effect and only very little shelf life effect. In contrast, the MSE-nose and GC/MS score plots clearly indicated the presence of both shelf life and storage history trend. Moreover, the volatile profile changes during shelf life depended on the storage history. The loading plots of the PCA of the GC/MS data revealed which volatiles are important to differentiate between storage conditions and which ones are important during ripening on the shelf.

Partial least square (PLS) models based on the three data sets to relate firmness and days of shelf life with the volatile production of apples were built based on the three data sets. It was found that the models based on the E-nose data had worse prediction performance than those based on the MSE-nose data. Both for firmness (0.95) and days of shelf life (0.98) a high cross-validation correlation was observed between measured and predicted values. The standard error of prediction (S.E.P.) of firmness and shelf life were 2.38×10⁶ Hz² g^2/3 and 1.02 days, respectively. Models based on the GC/MS data showed comparable results.

 

 

 

·                    S. Saevels, J. Lammertyn, A.Z. Berna, E.A. Veraverbeke, C. Di Natale, B. Nicolai; Electronic nose as a non destructive tool to evaluate the optimal harvest date of apples, Postharvest Biology and Technology 30 2003 3-14

An electronic nose (E-nose) has been evaluated for use as a tool to predict the optimal harvest date of apples (Malus domestica Borkh.). The volatiles of ‘Jonagold’ and ‘Braeburn’ apples were assessed during the preclimacteric stage for two consecutive harvest years by means of an E-nose. A principal component data analysis indicated the presence of both a year and cultivar effect. Partial least square (PLS) models were constructed based on data of both harvest years. The cultivar effect made it difficult to build accurate and robust models for the two cultivars together. As a consequence, calibration models were constructed based on data of 2 years, but for each cultivar separately. The prediction of maturity, according to the Streif Index, showed a cross-validation correlation of 0.89 and 0.92 for ‘Jonagold’ and ‘Braeburn’ fruit, respectively. The calibration models for the prediction of the maturity, defined as the number of days before commercial harvest had a validation correlation of 0.91 for ‘Jonagold’ and 0.84 for ‘Braeburn’ fruit. Individual quality characteristics (soluble solids, acidity, starch and firmness) were predicted reasonably well. The calibration model for soluble solids content resulted in a consistent validation correlation over the results over 2 years (0.76 and 0.77). The starch and firmness were predicted with a validation correlation between 0.72 and 0.80. The prediction of the total acidity was poor (validation correlation of 0.66 and 0.69). It was also demonstrated that the type of validation influences the model prediction performance. Care should be taken when interpreting and using the models to predict the optimal harvest date for other years and cultivars.

 

 

·                    C. Di Natale,M. Zude, A. Macagnano, R. Paolesse, B. Herold, A. D’Amico; Outer product analysis of electronic nose and visible spectra: application to the measurement of peach fruit characteristics, Analytica Chimica Acta 459 2002 107-117

Visual aspect and aroma are among the most important features of fruit that determine consumer preferences. Electronic nose and spectroscopic techniques have shown positive results in evaluating some basic analytical parameters of fruit and global features such as the cultivar.

In this paper, we illustrate and discuss a study aimed at evaluating the improvement derived by the fusion of visible spectra and electronic nose data. These experiments were performed on a population of yellow peaches belonging to two cultivars. Each sample was measured by visible optical spectroscopy and by electronic nose. In addition, a number of reference parameters were also measured by conventional destructive methodologies.

Collected data were analysed individually and then fused together in order to classify the two cultivars and to estimate the reference parameters. Data fusion was performed building the outer product matrix for each measurement. The set of matrices was then successively unfolded and analysed by conventional chemometrics tools.

Results were improved using outer products, for instance in classification average percentage errors of 25, 10, and 7 for electronic nose, spectra, and outer product, respectively was achieved. Regression analysis provides the evidence of a substantial orthogonal appearance of the datasets, which offer former hidden information on fruit classification.

 

 

·                    C. Di Natale, A. Mantini, E. Martinelli, A. Macagnano, R. Paolesse, E. Galassi, A. D’Amico; The evaluation of quality of post-harvest oranges and apples by means of an electronic nose, Sensors and Actuators B 78 2001 26-31

The measure of quality of post-harvest fruits is considered a promising application field for electronic nose technology such as the detection of defects. Among the possible defects present in fruits those due to post-harvest treatment are particularly important. Among them defects like mealiness (due to post-harvest over-ripening), skin damage (due to mechanical or temperature stresses), and infections affect strongly the perception of consumers. They have to be avoided in order to achieve high quality products.

In this paper, the study of the variations of aroma of oranges, during the storage, and apples, due to the presence of mealiness and skin damage by means of a thickness shear mode quartz resonators- (TSMR) based electronic nose, is illustrated and discussed.

Results have evidenced that the electronic nose has enough sensitivity and resolution to distinguish among the various classes and to correctly predict the amount of defects (for apples) and storage days (for oranges).

 

 

·                    M. Mascini, A. Macagnano, G. Scortichini, M. Del Carlo, G. Diletti, A. D’Amico, C. Di Natale, D. Compagnone; Biomimetic sensors for dioxine detection in food samples, Sensors and Actuators B 111 2005 102-105

In this work, gold based quartz crystals were modified with synthetic oligopeptides, designed as biomimetic traps using computational approach, to obtain piezoelectric sensors selective to the dioxins. After the optimisation of the methodology using standard solutions, as a practical analytical application, three food matrices (poultry, eggs and milk) spiked at three different dioxin levels were analysed. The cross-reactivity of the system was also quantified spiking the samples with commercial polychlorinated biphenyls (PCBs) and a mixture of PCBs and dioxins. The response of the sensors was not influenced by any of matrices tested either before or after the cleanup steps. The negligible matrix-effect could lead to a simplification of the extraction procedure. Basing on this screening method a rapid assignment of the samples to different degrees of toxicity could be possible reducing the use of high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS).

·                    Lamagna, S. Reich, M. Negri, A. Boselli, M. Cocco, C. Di Natale; Characterization of different brands used in a typical argentinean beverage -mate- by means of an e-nose, Thin Solid Films 418 2002 42-44

A qualitative analysis of different kinds of green leaves brands employed in a popular Argentinean beverage—mate—was performed with an electronic nose (EN) based on quartz microbalance sensors. We employed a LibraNose from Technobiochip, which contains eight sensors. Two types of ‘odours’ are analysed for each sample corresponding to short- and long-term periods after the opening of the package. Principal component analysis (PCA) is applied to the sensor responses and it is possible to distinguish between different brands through their locus in the plane defined by the first two PCA components. Preliminary results confirm the usefulness of this EN for classification and future quality control purposes.

 

 

·                    C. Di Natale, A. Macagnano, F. Davide, A. D’Amico, R. Paolesse, T. Boschi, M. Faccio, G. Ferri; An electronic nose for food analysis, Sensors and Actuators B 44 1997 521-526

Since the first developments of electronic noses, food analysis has been considered as one of its most useful applications. In this paper an electronic nose based on quartz microbalances coated with metallo-porphyrins and related compounds is presented and illustrated. Extensive tests on various substances playing key roles in food analysis show that sensing properties of the sensing materials (in terms of sensitivity and selectivity) can be exploited for electronic nose applications devoted to the analysis of various kinds of foods. The versatility of this system has been successfully tested on different kinds of foods, such as fish, meat, vegetable and wine for which results are shown.

 

 

Environment

 

·                    Baschirotto, S. Capone, A. D’Amico, C. Di Natale, V. Ferraglia, G. Ferri, L. Francioso, M. Grassi, N. Guerrini, P. Malcovati, E. Martinelli, P. Siciliano; A portable integrated wide-range gas sensing system with smart A/D front-end, Sensors and Actuators B 130 2008 164-174

In this paper, the development of a portable environmental monitoring system based on a gas sensor array is proposed. The most critical issues related to the microsensor, the interface circuit and the data analysis have been addressed. The complete system is designed to exhibit high precision and large dynamic range. Experimental results on a prototype, obtained by injecting ethanol on a microsensor coated with Pd-doped SnO₂, have confirmed the theoretical expectations, demonstrating that the system is suitable for high-precision gas sensing applications.

 

 

·                    E. Martinelli, E. Zampetti, S. Pantalei, F. Lo Castro, M. Santonico, G. Pennazza, R. Paolesse, G. MAscetti, V. Cotronei, F. Giannini, C. Di Natale, A. D’Amico; Design and test of an electronic nose for monitoring the air quality in the International Space Station, Microgravity Science and Technology 19 2008 60-64

Long-term manned space missions requires a continuous monitoringof the air quality inside the spacecraft. For this scope, among several different solutions, electronic noses have been considered. On behalf of European Space Agency an electronic nose specifically designed for air quality control in closed environment is under development. After several ground experiments concerning the monitoring of a biofilter efficiency, the instrument has been tested during the ENEIDE mission on board of the International Space Station. in this paper the instrument main concepts and its performance in ground and space experiments are illustrated.

 

 

·                    E. Martinelli, M. Stabile, A. Catini, R. Paolesse, A. D’Amico, C. Di Natale;An array of capacitive sensors based on commercial fingerprint detectors, Sensors and Actuators B 130 2008 264-268

Capacitance transduction is one of the many possibilities to translate a chemical binding event into an electric signal. However, only few examples of capacitive sensors have been presented because of the complex measurement set-up. Microfabrication offered recently the possibility to develop capacitive sensors but the technology is not available to all the researchers that necessitate to quickly test the sensing materials. Recently, as witnessed with optical sensors, low-cost fingerprint detectors have been released on the market and are currently widely available. Such detectors offer a flat surface endowed with thousands of capacitors that can be functionalized with chemical sensing layers to become chemical sensors. In this paper a demonstration of the possibilities of this technology is shown considering as sensing layer a number of metalloporphyrins, a material yet studied for chemical sensors development. Results show that a good detection of carbon monoxide, ethanol and triethylamine is achieved. The large number of sensors allows also to exploite a number of paradigms learnt from the physiology of olfaction.

 

Biomedical

 

 

·                    C. Di Natale, A. Macagnano, E. Martinelli, R. Paolesse, G. D’Arcangelo, C. Roscioni, A. Finazzi-Agrò, A. D’Amico; Lung cancer identification by the analysis of breath my means of an array of non-selective gas sensors, Biosensors and Bioelectronics 18 2003 1209-1218

Previous finding shown that the composition of the breath of patients with lung cancer contains information that could be used to detect the disease. These volatiles are mainly alkanes and aromatic compounds. Sensor arrays technology (electronic nose) proved to be useful to screen samples characterised by different headspace composition. Here we investigated the possibility of using an electronic nose to check whether volatile compounds present in expired air may diagnose lung cancer. Breath samples were collected and immediately analysed by an electronic nose. A total of 60 individuals were involved in the experiment. 35 of them were affected by lung cancer, 18 individuals were measured as reference and nine were measured after the surgical therapy. Two individuals were measured twice, before and after the surgical therapy, for a total of 62 measurements. An electronic nose, composed by eight quartz microbalance (QMB) gas sensors, coated with different metalloporphyrins, was used. These sensors show a good sensitivity towards those compounds previously indicated as possible lung cancer markers in breath. The application of a ‘partial least squares-discriminant analysis’ (PLS-DA) found out a 100% of classification of lung cancer affected patients, 94% of reference was correctly classified. The class of post-surgery patients were correctly individuated in 44% of the cases, while the other samples were classified as healthy references. The alteration of breath composition induced by the presence of lung cancer was enough to allow a complete identification of the sample of diseased individuals. Extended studies are necessary to evaluate the resolution of the method, namely the stage at which the disease may be identified in order to use this instrument for early diagnosis.

 

 

·                    D’Amico, R. Bono, G. Pennazza, M. Santonico, G. Mantini, M. Bernabei, M. Zarlenga, C. Roscioni, E. Martinelli, R. Paolesse, C. Di Natale; Identification of melanoma with a gas sensor array, Skin Research and Technology 14 2008 226-236

Background/purpose: The relationship between diseases and alterations of the airborne chemicals emitted from the body has been found in many different pathologies and in particular for various forms of cancer. Metabolism of cancer cells is greatly altered during their lifetime; then, modification of chemicals is supposed to be large around cancer tissues. Positive hints in this direction were provided, as an example, on studying the breath composition of lung canceraffected subjects. Besides the conventional analytical approaches, in recent years sensor arrays were also applied to these researches considering the chemical composition changes as those occurring in other applications such as for instance, those dealing with food quality measurements .Methods: In this paper, the first application of sensor arrays to study the differentiation between melanomas and nevi, namely malignant and benign affection of melanocytary cells, respectively, is presented and discussed. The localization of lesions on the skin surface made possible the utilization of differential measurements aimed at capturing the differences between two adjacent skin regions. This approach strongly reduces the influence of skin headspace variability due to the peculiar subjective odour background and the skin odour variability. The measurement campaign involved 40 cases; 10 of these were diagnosed melanomas referred to surgical intervention. Nine of these diagnoses were further confirmed by histological examinations of the removed tissue and one was a false positive. Results: The differences in the chemical composition of headspace were verified with a gas-chromatographic investigation, and the classification of electronic nose data provided an estimated cross-validated accuracy of the same order of magnitude as the currently used diagnostic instruments. Conclusion: Electronic nose sensors have been shown to have good sensitivity towards volatile organic compounds emitted by skin lesions, and the method seems to be effective for malign lesions identification. The results presented in this paper encourage a second experimental campaign with a larger number of participants and a systematicuse of gas chromatography mass spectrometer technology in order to identify some possible melanoma biomarkers.

 

 

·                    A.D’Amico, C. Di Natale, R. Paolesse, A. Macagnano, E. Martinelli, G. Pennazza, M. Santonico, M. Bernabei, C. Roscioni, G. Galluccio, R. Bono, E. Finazzi-Agrò, S. Rullo; Olfactory systems for medical applications, Sensors and Actuators B 130 2008 458-465

Prevention strategy is nowadays the main way in the complex issue of medical diagnosis. In this wake, performing non-invasive medical tests oriented to an early diagnosis is one of the challenges for the promotion of new classes of instruments and for a faster intervention on the patient.

Clinical chemistry is the starting point of this challenge due to the fact that its scope is the quantification of specific compounds found in urine and blood, known to be related to specific pathologies.

This paper will deal with an overview of the electronic nose (EN) applications in medicine and in particular with recent data related to the following pathologies: lung cancer, schizophrenia, melanoma.

The design of an appropriate measurement protocol for each of the above mentioned applications is a crucial point of these studies, in order to guarantee the representativeness of the measured samples and the reproducibility of the experiments.

The efforts spent so far have produced many stimulant and promising results together with fundamental questions about the real potentialities of this technology in medical fields and about the physiological mechanism involved in the modification of the chemical compounds related to the studied diseases. Results, related to the above-mentioned pathologies, related to the EN application will be illustrated and commented.

 

 

·                    M. Bernabei, G. Pennazza, M. Santonico, C. Corsi, C. Roscioni, R. Paolesse, C. Di Natale, A. D’Amico; A preliminary study on the possibility to diagnose urinary tract cancers by an electronic nose, Sensors and Actuators B 131 2008 1-4

In this paper a study about the possibility of an early and non-invasive diagnosis of urinary tract cancers with an electronic nose is presented. Measurements of urine headspace were performed by means of an electronic nose based on eight quartz crystal microbalance (QCM) gas sensors coated with different metalloporphyrins. A total of 113 patients affected by various urological pathologies were involved in the experiment, 19 of them were measured twice, before and after the surgical treatment of the cancer. 18 healthy volunteers were used as a reference population. The e-nose data were processed by both principal component analysis (PCA) and discriminant analysis solved by partial least square (PLS-DA). The PLS-DA model related to the data of the healthy and the ills individuals, except the post-surgery samples, shows a complete discrimination between these two groups and a gradual differentiation between prostate and bladder cancer. The application of PCA to the whole data set, shows a migration of the post-surgery class towards the healthy group, suggesting that the headspace of urine samples of patients with the urinary tract cancer is different from that of healthy individuals.

These preliminary results confirm a strict correlation between urine headspace and urological pathologies, enhancing the possibility to perform early diagnosis, considered of upmost importance along the medical diagnostic path.

 

 

·                    G. Pennazza, E. Marchetti, M. Santonico, G. Mantini, S. Mummolo, G. Marzo, R. Paolesse, C. Di Natale, A. D’Amico; Application of quartz microbalance gas sensor array for the study of halitosis, Journal of Breath Research 2 2008

Research into the monitoring and control of oral malodor has nowadays received new stimulus from the importance gained by this phenomenon as a medical and social problem. In this paper the performance of an electronic nose to detect this manifestation has been investigated in order to explore the possibility of using this instrument as a complement to those already existing for the assessment of oral malodor. In particular, a breath sampling procedure has been optimized to maximize the transfer to the sensors of those molecules that are known to be associated with the malodor. The sensitivity of electronic nose sensors to hydrogen sulfide, butyric acid and valeric acid—three compounds known to play a major role in halitosis—has been measured and the results indicate that the threshold limits are compatible with halitosis detection. An experiment with real and artificial samples indicates the possibility of identifying halitosis-affected individuals and of discriminating them according to breath composition.

 

 

·                    C. Di Natale, R. Paolesse, G. D’Arcangelo, P. Comandini, G. Pennazza, E. Martinelli, S. Rullo, M.C. Roscioni, C. Roscioni, A. Finazzi-Agrò, A. D’Amico; Identification of schizophrenic patients by examination of body odor using gas chromatography-mass spectrometry and a cross selective gas sensor array, Medical Science Monitor 11 2005 366-375

BACKGROUND: Previous findings have shown that the body odor of patients affected by schizophrenia contains some specific compounds. Chemical sensor technology has proved to be able to classify different odours. We investigated the possibility of using a chemical sensor array to detect body odor alteration in schizophrenic patients.

MATERIAL/METHODS: The sweat of subjects was sampled and analysed by Gas Chromatography-Mass Spectrometry (GC-MS) and by an array of cross-selective gas sensors. A total of 27 individuals were involved in the experiment: 9 schizophrenics, 9 with other mental disorders, and 9 controls.

RESULTS: GC-MS analysis showed a richer composition for the sweat of schizophrenic patients. Nevertheless, the individuation of specific markers was unsuccessful. On the other hand, statistical analysis of cross-selective gas sensor data provided a complete classification of schizophrenic patients with respect to the other three groups.

CONCLUSIONS: The alteration of body odor in schizophrenic patients was confirmed by GC-MS and chemical sensor array. Results show that the alteration is complex and cannot be limited to a single compound, but rather to a global variation of the body odor.

 

 

·                    H. Willers, P. de Gijsel, N. Ogink, A. D’Amico, E. Martinelli, C. Di Natale, N. Van Ras, J. Van der Waarde; Monitoring of biological odour filtration in closed environments with olfactometry and an electronic nose, Water Science and Technology 50 2004 93-100

Air treatment with a compact biological membrane filter, and air quality monitoring with an electronic nose were tested in the laboratory on air from a cage containing six mice. Additional analyses of air to and from the filter were performed using olfactometry and ammonia and hydrogen sulphide gas detection tubes. The biological air filter is a module containing biofilm-coated membrane fibres that separate a closed liquid loop from a gas phase. Odour compounds and oxygen diffuse through the membranes from the gas phase to the biofilm, where they are degraded to carbon dioxide and water. The prototype "ENQBE" electronic nose is based on an array of eight thickness shear mode resonators (TSMR), also known in the literature as quartz microbalance sensors. The chemical sensitivity is given by molecular films of metalloporphyrins and similar compounds. Chemical interaction of compounds in the air with the vibrating sensors induces a frequency change of the vibration that can be measured as a signal. The air from the mouse cage had a strong odour (3490 OUE/m3). The biological membrane filter performed well, achieving over 80% odour and ammonia reduction. The electronic nose signal could be correlated with the inlet and outlet air-quality of the biological filter, making it a promising method for monitoring air quality in closed environments.

 

 

·                    C. Di Natale, A. Macagnano, R. Paolesse, A. Mantini, E. Tarizzo, A. D’Amico; Human skin odor analysis by means of an electronic nose, Sensors and Actuators B 65 2000 216-219

Electronic noses have been applied to several disciplines such as food analysis, environmental control and industrial processes. In this paper the use of electronic noses in medicine is introduced and discussed. In this paper a review about the main features of human body odor is given. First experiments concerned with the measurement of the sensitivity of sensors towards a particular constituent of the skin odor, and preliminary results of a survey of skin-odor analysis in a population of individuals are reported. Findings encourage pursuing this research direction that can give rise to a better comprehension of the role of smell and odor in humans and, in the next future, to a novel diagnostic tool.

 

 

·                    C. Di Natale, A. Mantini, A. Macagnano, D. Antuzzi, R. Paolesse, A. D’Amico; Electronic nose analysis of urine samples containing blood, Physiological measurements 20 2000 377-384

In this paper the possible application of an electronic nose to the analysis of urine is presented. In contrast with the conventional applications of sensors and biosensors operating in liquid, the approach discussed here makes use of gas sensors performing an analysis of the headspace. The application deals with urine samples from patients affected by kidney diseases; some of the samples contained traces of blood. Results show the possibility of distinguishing the samples containing blood from the others, and a linear correlation between the first three principal components and the blood content was found. Furthermore, the electronic nose matched with a suitable neural network showed good performance in measuring the pH and the specific weight of the samples.

 

 

·                    Mantini, C. Di Natale, A. Macagnano, R. Paolesse, A. Finazzi-Agrò, A. D’Amico; Biomedical applications of an electronic nose, Critical Review in Biomedical Engineering 28 2000 481-485

The analysis of volatiles secreted outside the human body to get information on the health status of the individuals has been proposed several times in the past. This kind of analysis is complex both from the point of view of sample collection and data interpretation when, for instance, gas chromatography is utilized. In the recent years the advent of chemical sensors and chemical sensors systems (the so-called electronic noses) opened the way to the possibility of fast and simple analysis of odors in many fields, and, recently, among them, in medicine. In this paper some examples of these applications are illustrated. The results, although preliminary, encourage in pursuing these researches that can give rise to a better comprehension of the role of smell and odor in humans and, possibly in the near future, in novel diagnostic tools.