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Electronic Nose (electronic + nose)
Terms modified by Electronic Nose Selected AbstractsDETECTION OF OLIVE OIL ADULTERATION WITH RAPESEED AND SUNFLOWER OILS USING MOS ELECTRONIC NOSE AND SMPE-MSJOURNAL OF FOOD QUALITY, Issue 1 2010SYLWIA MILDNER-SZKUDLARZ ABSTRACT The study analyzed the effectiveness of two types of electronic nose systems to detect adulteration of extra virgin olive oil (EVOO) with rapeseed and sunflower oils. Tested methods included volatile analysis with the electronic nose based on MOS sensors (HS-E nose) and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS. Samples of EVOO were mixed with different proportions, ranging from 5 to 50% (v/v), of seed oils and fingerprints of volatile profiles of all samples were generated. In order to obtain as much chemical information as possible and to find a volatile marker to detect adulterations of EVOO with seed oils, principal component analysis (PCA) and partial least squares (PLS) analyses were applied to the data. The application of PCA and PLS analyses to the data from two electronic noses and SMPE-GC/MS were sufficient to differentiate the adulterated samples from pure EVOO. Excellent results were obtained in the prediction of the percentage of adulteration by PLS analysis. SPME-GC-MS analysis with subsequent PCA yielded good results; however, it was time-consuming. The two electronic noses, with subsequent PCA treatment of data, offering the advantages of rapidity and reliability, enabled detection of olive oil adulteration with different contents of seed oils. PRACTICAL APPLICATIONS Virgin olive oil is highly appreciated by consumers due to its nutritional benefits. Thus, its adulteration with low-grade olive oils or cheaper vegetable oils could potentially be very profitable for sellers or raw material suppliers and may yield large economic profits. In this way, authentication of virgin olive oils has become an interesting subject from both commercial and health perspectives. It has been proved that the two proposed types of electronic nose systems facilitate reliable detection of rapeseed and sunflower oils in extra virgin olive oil. Both MOS and MS electronic noses are faster than the conventional SMPE-GC/MS analysis. These well-correlated methodologies, offering the advantages of rapidity and reliability, opened up a new way of detecting adulteration of virgin olive oils. [source] Prediction of Microbial and Sensory Quality of Cold Smoked Atlantic Salmon (Salmo salar) by Electronic NoseJOURNAL OF FOOD SCIENCE, Issue 9 2005Gudrun Olafsdottir ABSTRACT: Quality changes of cold smoked salmon from 4 different smokehouses in Europe were monitored by a prototype gas-sensor array system, the FishNose. Samples were stored in different packaging (vacuum and Modified Atmosphere Packaging [MAP]) for up to 4 wk under controlled storage conditions at 5 °C and 10 °C. Quality criteria based on sensory attributes (sweet/sour, off, and rancid odor), and total viable counts and lactic acid bacteria counts were established and used for classification of samples based on the responses of the FishNose. The responses of the gas-sensors correlated well with sensory analysis of spoilage odor and microbial counts suggesting that they can detect volatile microbially produced compounds causing spoilage odors in cold-smoked salmon during storage. The system is therefore ideal for fast quality control related to freshness evaluation of smoked salmon products. Partial least squares (PLS) regression models based on samples from single producer showed better performance than a global model based on products from different producers to classify samples of different quality. [source] Microbial and Sensory Assessment of Milk with an Electronic NoseJOURNAL OF FOOD SCIENCE, Issue 2 2002F. Korel ABSTRACT: An electronic nose (e-nose) was used to assess milk odor inoculated with Pseudomonas fluorescens or Bacillus coagulans, and odors were correlated with microbial loads and sensory scores. Sterile whole, reduced-fat, and fat-free milk were inoculated, stored at 1.7, 7.2, and 12.8 °C, and evaluated at d 0, 3, 5, 7, and 10 by e-nose and sensory panel. Aerobic plate counts were performed. E-nose readings, microbial counts, and sensory data were analyzed using discriminant function analysis. The e-nose discriminated differences in odor due to microbial load and sensory data. This may lead to a rapid method for determining sensory evaluation and microbial loads of milk. [source] The Diagnostic Utility of an Electronic Nose: Rhinologic ApplicationsTHE LARYNGOSCOPE, Issue 9 2002Erica R. Thaler MD Abstract Objective/Hypothesis The thesis explores the applicability of electronic nose technology in medical decision-making. Specifically, the studies undertaken in the thesis were designed to test the ability of the electronic nose to assist in diagnostic questions encountered in the field of rhinology. Study Design Three separate studies were undertaken. All involved analysis of specimens by the electronic nose, obtained either in vitro or in vivo: known matched sets of cerebrospinal fluid and serum, bacterial samples from known plated specimens, and culture swabs taken from patients suspected of having rhinosinusitis who also had a matched standard bacterial culture taken from the same site. The goal of analysis was to determine whether the electronic nose was able to identify or categorize specimens or groups of specimens. Methods Each specimen was tested using the organic semiconductor-based Cyranose 320 electronic nose. Data from the 32-element sensor array were subjected to principal-component analysis to depict differences in odorant patterns. Distinction of specimens was identified by calculation of Mahalanobis distance. Results The electronic nose was able to distinguish serum from cerebrospinal fluid in pure isolates as well as in isolates collected on small cottonoid pledgets at amounts of 0.2 mL or greater. It was also able to distinguish between control swabs and bacterial samples as well as among bacterial samples collected in vitro. Preliminary work suggests that it may be able to distinguish between presence and absence of bacterial infection in specimens collected on nasal swabs. Conclusions The electronic nose is able to distinguish reliably between cerebrospinal fluid and serum sampled in small amounts, may be able to identify presence and type of bacterial pathogen in vitro, and is able to identify presence or absence of bacteria on nasal swabs. Because this information is available immediately, the electronic nose may be a powerful new technology for diagnostic use, not only for rhinologic purposes but in many other aspects of medicine as well. [source] Effect of drying process on lemon verbena (Lippia citrodora Kunth) aroma and infusion sensory qualityINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2010Rodrigo Infante Summary Lemon verbena leaves are used as herbal infusion due to their aromatic, digestive and antispasmodic properties. The aim of the present study was to determine the sensory quality of lemon verbena infusions prepared with fresh leaves, dried leaves at 30 °C and 60 °C. Infusion aroma and taste was determined through a trained sensory panel and an electronic nose (e-nose). Infusion acceptability was evaluated through a consumer test. All drying treatments on day 0 were grouped together regarding the e-nose determination. ,Floral' descriptors were related to leaves not submitted to store. When the leaves were stored for 30 days, aroma attributes were lost. Differences on the infusion acceptability were ascribable to the drying method. Infusions prepared with fresh leaves showed the highest acceptability. E-nose could be used as a reliable tool for characterising the quality of aromatic herbs. [source] Applications of electronic noses and tongues in food analysisINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2004Anil K. Deisingh Summary This review examines the applications of electronic noses and tongues in food analysis. A brief history of the development of sensors is included and this is illustrated by descriptions of the different types of sensors utilized in these devices. As pattern recognition techniques are widely used to analyse the data obtained from these multisensor arrays, a discussion of principal components analysis and artificial neural networks is essential. An introduction to the integration of electronic tongues and noses is also incorporated and the strengths and weaknesses of both are described. Applications described include identification and classification of flavour and aroma and other measurements of quality using the electronic nose. The uses of the electronic tongue in model analyses and other food, beverage and water monitoring applications are discussed. [source] Hildebrand and Hansen solubility parameters from Molecular Dynamics with applications to electronic nose polymer sensorsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 15 2004M. Belmares Abstract We introduce the Cohesive Energy Density (CED) method, a multiple sampling Molecular Dynamics computer simulation procedure that may offer higher consistency in the estimation of Hildebrand and Hansen solubility parameters. The use of a multiple sampling technique, combined with a simple but consistent molecular force field and quantum mechanically determined atomic charges, allows for the precise determination of solubility parameters in a systematic way (, = 0.4 hildebrands). The CED method yields first-principles Hildebrand parameter predictions in good agreement with experiment [root-mean-square (rms) = 1.1 hildebrands]. We apply the CED method to model the Caltech electronic nose, an array of 20 polymer sensors. Sensors are built with conducting leads connected through thin-film polymers loaded with carbon black. Odorant detection relies on a change in electric resistivity of the polymer film as function of the amount of swelling caused by the odorant compound. The amount of swelling depends upon the chemical composition of the polymer and the odorant molecule. The pattern is unique, and unambiguously identifies the compound. Experimentally determined changes in relative resistivity of seven polymer sensors upon exposure to 24 solvent vapors were modeled with the CED estimated Hansen solubility components. Predictions of polymer sensor responses result in Pearson R2 coefficients between 0.82 and 0.99. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1814,1826, 2004 [source] DETECTION OF OLIVE OIL ADULTERATION WITH RAPESEED AND SUNFLOWER OILS USING MOS ELECTRONIC NOSE AND SMPE-MSJOURNAL OF FOOD QUALITY, Issue 1 2010SYLWIA MILDNER-SZKUDLARZ ABSTRACT The study analyzed the effectiveness of two types of electronic nose systems to detect adulteration of extra virgin olive oil (EVOO) with rapeseed and sunflower oils. Tested methods included volatile analysis with the electronic nose based on MOS sensors (HS-E nose) and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS. Samples of EVOO were mixed with different proportions, ranging from 5 to 50% (v/v), of seed oils and fingerprints of volatile profiles of all samples were generated. In order to obtain as much chemical information as possible and to find a volatile marker to detect adulterations of EVOO with seed oils, principal component analysis (PCA) and partial least squares (PLS) analyses were applied to the data. The application of PCA and PLS analyses to the data from two electronic noses and SMPE-GC/MS were sufficient to differentiate the adulterated samples from pure EVOO. Excellent results were obtained in the prediction of the percentage of adulteration by PLS analysis. SPME-GC-MS analysis with subsequent PCA yielded good results; however, it was time-consuming. The two electronic noses, with subsequent PCA treatment of data, offering the advantages of rapidity and reliability, enabled detection of olive oil adulteration with different contents of seed oils. PRACTICAL APPLICATIONS Virgin olive oil is highly appreciated by consumers due to its nutritional benefits. Thus, its adulteration with low-grade olive oils or cheaper vegetable oils could potentially be very profitable for sellers or raw material suppliers and may yield large economic profits. In this way, authentication of virgin olive oils has become an interesting subject from both commercial and health perspectives. It has been proved that the two proposed types of electronic nose systems facilitate reliable detection of rapeseed and sunflower oils in extra virgin olive oil. Both MOS and MS electronic noses are faster than the conventional SMPE-GC/MS analysis. These well-correlated methodologies, offering the advantages of rapidity and reliability, opened up a new way of detecting adulteration of virgin olive oils. [source] Differentiation of Closely Related Fungi by Electronic Nose AnalysisJOURNAL OF FOOD SCIENCE, Issue 6 2007K. Karlshøj ABSTRACT:, In this work the potential of electronic nose analysis for differentiation of closely related fungi has been described. A total of 20 isolates of the cheese-associated species Geotrichum candidum, Penicillium camemberti, P. nordicum, and P. roqueforti and its closely related species P. paneum, P. carneum as well as the noncheese-associated P. expansum have been investigated by electronic nose, GC-MS, and LC-MS analysis. The isolates were inoculated on yeast extract sucrose agar in 20-mL headspace flasks and electronic nose analysis was performed daily for a 7-d period. To assess which volatile metabolites the electronic nose potentially responded to, volatile metabolites were collected by diffusive sampling overnight onto tubes containing Tenax TA, between the 7th and 8th day of incubation. Volatiles were analyzed by gas chromatography coupled to mass spectrometry and the results indicated that mainly alcohols (ethanol, 2-methyl-1-propanol, and 3-methyl-1-butanol) and ketones (acetone, 2-butanone, and 2-pentanone) were produced at this stage. The volatile metabolite profile proved to be species specific. Nonvolatile metabolites were collected on the 8th day of incubation and mycotoxin analysis was performed by high pressure liquid chromatography coupled to a diode array detector and a time of flight mass spectrometer. Several mycotoxins were detected in samples from the species P. nordicum, P. roqueforti, P. paneum, P. carneum, and P. expansum. Differentiation of closely related mycotoxin producing fungi incubated on yeast extract sucrose agar has been achieved, indicating that there is a potential for predicting production of mycotoxins on food and feedstuffs by electronic nose analysis. [source] Effect of Gamma-Irradiated Red Pepper Powder on the Chemical and Volatile Characteristics of Kakdugi, a Korean Traditional Fermented Radish KimchiJOURNAL OF FOOD SCIENCE, Issue 7 2005Jeung Hee Lee ABSTRACT The chemical and volatile characteristics of kakdugi batches prepared with irradiated red pepper powders were determined during fermentation for 7 wk at 5 °C. Acidities of kakdugies with irradiated red pepper powder (3, 5, and 7 kGy) were lower than that of kakdugi with nonirradiated control at 3 wk of fermentation, which indicated that the irradiated red pepper powder might delay the initial fermentation. Pungency and red color caused by capsanoids and capsanthin, respectively, were not altered by irradiated red pepper powder, whereas the fermentation decreased the capsanoid content. The headspace volatile compounds extracted by solid-phase microextraction, except 2-tricanone, were not significantly different in fresh made kakdugies with red pepper powder irradiated at dosed of 0, 3, 5, and 7 kGy; however, as fermentation progressed, the composition of volatiles was changed. A FOX 3000 electronic nose separated the odor of kakdugies with red pepper powder irradiated at 0, 3, 5, and 7 kGy into 4 different groups, and the odor patterns developed differently during fermentation. [source] Electronic Nose Technology in Quality Assessment: Predicting Volatile Composition of Danish Blue Cheese During RipeningJOURNAL OF FOOD SCIENCE, Issue 6 2005Jeorgos Trihaas ABSTRACT This work describes for the 1st time the use of an electronic nose (e-nose) for the determination of changes of blue cheeses flavor during maturation. Headspace analysis of Danish blue cheeses was made for 2 dairy units of the same producer. An e-nose registered changes in cheeses flavor 5, 8, 12, and 20 wk after brining. Volatiles were collected from the headspace and analyzed by gas chromatography-mass spectrometry (GC-MS). Features from the chemical sensors of the e-nose were used to model the volatile changes by multivariate methods. Differences registered during ripening of the cheeses as well as between producing units are described and discussed for both methods. Cheeses from different units showed significant differences in their e-nose flavor profiles at early ripening stages but with ripening became more and more alike. Prediction of the concentration of 25 identified aroma compounds by e-nose features was possible by partial least square regression (PLS-R). It was not possible to create a reliable predictive model for both units because cheeses from 1 unit were contaminated by Geotrichum candidum, leading to unstable ripening patterns. Correction of the e-nose features by multiple scatter correction (MSC) and mean normalization (MN) of the integrated GC areas made correlation of the volatile concentration to the e-nose signal features possible. Prediction models were created, evaluated, and used to reconstruct the headspace of unknown cheese samples by e-nose measurements. Classification of predicted volatile compositions of unknown samples by their ripening stage was successful at a 78% and 54% overall correct classification for dairy units 1 and 2, respectively. Compared with GC-MS, the application of the rapid and less demanding e-nose seems an attractive alternative for this type of investigation. [source] Effect of Gamma-irradiation on Color, Pungency, and Volatiles of Korean Red Pepper PowderJOURNAL OF FOOD SCIENCE, Issue 8 2004J.H. Lee ABSTRACT: Effect of gamma-irradiation on color, pungency, and volatiles of Korean red pepper powder (Capsicum annuum L.) was investigated. Red pepper powder, vacuum-packaged in a polyethylene/polypropylene bag, was gamma-irradiated up to 7 kGy. An irradiation dose of 7 kGy reduced the population of mesophilic bacteria and fungi effectively without affecting major quality factors. Pungency of irradiated red pepper powder was not changed based on the amount of capsanoids by high-performance liquid chromatography (HPLC) and the Scoville sensory score. The red color of irradiated pepper powder was not significantly different from that of the control, judged from the capsanthin content by HPLC and color assessment using spectrophotpmetric (American Spice Trade Assn. units) and colorimetric measurements (Hunter a values). Further, the sensory evaluation showed no significant difference in pungent odor and off-odor between nonirradiated control and irradiated red pepper powder. However, when headspace volatiles of gamma-irradiated red pepper powder were evaluated by gas chromatography/ mass spectrometry with solid-phase microextraction and electronic nose with metal oxide sensors, the profiles of odor were classified into irradiated dose levels of 0, 3, 5, and 7 kGy by principal component analysis and multivariate analysis of variance. Such a difference of odor might result from the disappearance of some volatiles, such as hexanoic acid and tetramethyl-pyrazine, and the appearance of 1,3-di-tert-butylbenzene during irradiation. Moreover, it appears that the irradiation of packaging material induced a formation of 1,3-di-tertbutylbenzene, which migrated into the red pepper powder. [source] Microbial and Sensory Assessment of Milk with an Electronic NoseJOURNAL OF FOOD SCIENCE, Issue 2 2002F. Korel ABSTRACT: An electronic nose (e-nose) was used to assess milk odor inoculated with Pseudomonas fluorescens or Bacillus coagulans, and odors were correlated with microbial loads and sensory scores. Sterile whole, reduced-fat, and fat-free milk were inoculated, stored at 1.7, 7.2, and 12.8 °C, and evaluated at d 0, 3, 5, 7, and 10 by e-nose and sensory panel. Aerobic plate counts were performed. E-nose readings, microbial counts, and sensory data were analyzed using discriminant function analysis. The e-nose discriminated differences in odor due to microbial load and sensory data. This may lead to a rapid method for determining sensory evaluation and microbial loads of milk. [source] Electronic nose analysis of volatile compounds from poultry meat samples, fresh and after refrigerated storage,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2002Dorothy D, H Boothe Abstract Electronic nose technology has previously been applied to the assessment of the quality of red meats, pork and fish, but not poultry products. In the present study the ability of the electronic nose to assess the microbiological quality of raw poultry meat as a function of storage time and temperature was investigated. Four types of chicken pieces (boneless breast with and without skin, wings and thighs) were stored for up to 2 days at 13,°C (the maximum allowable temperature in poultry processing environments) or for up to 5 days at 4,°C (refrigeration temperature for raw poultry products prior to shipping or further processing). Saline rinses of meat samples were serially diluted in tryptic soy broth to 10,10. The rinses and their associated serial dilutions were analysed on an electronic nose with 12 metal oxide sensors in order to determine the specificity and sensitivity respectively of the assay. Principal component analysis (PCA) maps of the data confirmed that the electronic nose could differentiate volatile compounds associated with individual types of meat samples properly stored at 4,°C from those maintained at processing temperature, 13,°C, for a comparable time, even as early as day 1 of storage. Differences in headspace gases from any type of meat sample stored at one temperature could also be determined with increased storage time. However, data from samples stored at 4,°C clustered more tightly in PCA maps than those associated with samples maintained at 13,°C, indicating a greater diversity in volatile compounds at the higher temperature. We have shown herein that the electronic nose can detect changes in the volatile compounds associated with chicken meat based on product storage time and temperature; the technology can assess length of sample storage as well as deviation from refrigeration temperature. Published in 2002 for SCI by John Wiley & Sons, Ltd. [source] Recognition of anaerobic bacterial isolates in vitro using electronic nose technologyLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2002A. Pavlou Aims: Use of an electronic nose (e.nose) system to differentiation between anaerobic bacteria grown in vitro on agar media. Methods and Results: Cultures of Clostridium spp. (14 strains) and Bacteroides fragilis (12 strains) were grown on blood agar plates and incubated in sampling bags for 30 min before head space analysis of the volatiles. Qualitative analyses of the volatile production patterns was carried out using an e.nose system with 14 conducting polymer sensors. Using data analysis techniques such as principal components analysis (PCA), genetic algorithms and neural networks it was possible to differentiate between agar blanks and individual species which accounted for all the data. A total of eight unknowns were correctly discriminated into the bacterial groups. Conclusions: This is the first report of in vitro complex volatile pattern recognition and differentiation of anaerobic pathogens. Significance and Impact of the Study: These results suggest the potential for application of e.nose technology in early diagnosis of microbial pathogens of medical importance. [source] Development of electronic nose method for evaluation of residual solvents in low-density polyethylene films ,PACKAGING TECHNOLOGY AND SCIENCE, Issue 2 2007Isinay E. Yüzay Abstract Flexible packaging films containing high levels of residual volatile organic compounds (VOCs) can alter the flavour and odour of packaged foods. Currently, a range of gas chromatographic techniques and sensory evaluations are used for assessing the residual VOCs in packaging films. An objective method for assessing the residual solvents from low-density polyethylene (LDPE) was developed using an Alpha MOS Fox 3000 electronic nose (e-nose) equipped with 12 metal oxide semiconductor sensors. Three VOCs, ethyl acetate, ethyl alcohol and toluene, were chosen as models for solvents of interest in flexible food packaging analysis. LDPE film samples were spiked with single and binary mixtures of solvents and analysed using the e-nose and by GC,FID (HP 6890; Hewlett-Packard Co., Wilmington, DE). The responses obtained from the e-nose were processed using principal component analysis (PCA) and discriminate factorial analysis (DFA) in order to identify the residual solvents. Partial least squares analysis (PLS) was also used to quantify the amount of residual solvent and to correlate the e-nose results with gas chromatography, which is currently the standard method for determining residual VOCs in packaging films. There was good agreement between the e-nose responses and gas chromatography results for single solvents (r = 0.90,0.98). The technique also worked for binary solvent mixtures (r = 0.84,0.99). The electronic nose can be a viable alternative to traditional techniques while providing simplicity and objectivity, which would be extremely advantageous in routine quality control of residual solvents. Copyright © 2006 John Wiley & Sons, Ltd. [source] The Diagnostic Utility of an Electronic Nose: Rhinologic ApplicationsTHE LARYNGOSCOPE, Issue 9 2002Erica R. Thaler MD Abstract Objective/Hypothesis The thesis explores the applicability of electronic nose technology in medical decision-making. Specifically, the studies undertaken in the thesis were designed to test the ability of the electronic nose to assist in diagnostic questions encountered in the field of rhinology. Study Design Three separate studies were undertaken. All involved analysis of specimens by the electronic nose, obtained either in vitro or in vivo: known matched sets of cerebrospinal fluid and serum, bacterial samples from known plated specimens, and culture swabs taken from patients suspected of having rhinosinusitis who also had a matched standard bacterial culture taken from the same site. The goal of analysis was to determine whether the electronic nose was able to identify or categorize specimens or groups of specimens. Methods Each specimen was tested using the organic semiconductor-based Cyranose 320 electronic nose. Data from the 32-element sensor array were subjected to principal-component analysis to depict differences in odorant patterns. Distinction of specimens was identified by calculation of Mahalanobis distance. Results The electronic nose was able to distinguish serum from cerebrospinal fluid in pure isolates as well as in isolates collected on small cottonoid pledgets at amounts of 0.2 mL or greater. It was also able to distinguish between control swabs and bacterial samples as well as among bacterial samples collected in vitro. Preliminary work suggests that it may be able to distinguish between presence and absence of bacterial infection in specimens collected on nasal swabs. Conclusions The electronic nose is able to distinguish reliably between cerebrospinal fluid and serum sampled in small amounts, may be able to identify presence and type of bacterial pathogen in vitro, and is able to identify presence or absence of bacteria on nasal swabs. Because this information is available immediately, the electronic nose may be a powerful new technology for diagnostic use, not only for rhinologic purposes but in many other aspects of medicine as well. [source] The olive oil by-product in ,rainbow trout Onchorynchus mykyss (Walbaum)' farming: productive results and quality of the productAQUACULTURE RESEARCH, Issue 10 2010Benedetto Sicuro Abstract The aim of this work is to investigate olive oil by-product [vegetation water (VW)] inclusion in rainbow trout diet and its effect on the productive traits and the quality of the product. Two levels of VW inclusion were used and one control group was included. Fish diets were isonitrogeonous (crude protein 40%) and isoenergetic (18 MJ kg,1 DM). Two thousand and four hundred rainbow trout were used. An in vivo digestibility experiment was performed in order to determine diets' digestibility. All the fish diets and fillets were analysed to determine the proximate and fatty acid composition. On final fish fillet, lipid oxidation was determined at 0, 24, 48, 72, 96 and 192 h of storage using the 2-thiobarbituric acid method (thiobarbituric acid reactive substances). Aroma analyses on the final cooked and raw fillet were performed using an electronic nose. The VW inclusion partially reduced protein digestibility. The fish growth varied between 1.08% and 1.1% day. The supplemental level of VW led to a better antioxidant status of fish fillet, in particular, in the fillet sample after 72 h of fillet conservation. Principal component analysis in raw and cooked fish fillet indicates that the VW inclusion in the fish diet led to aroma modification on fish fillet. [source] Growth Behavior in Plant Cell Cultures Based on Emissions Detected by a Multisensor ArrayBIOTECHNOLOGY PROGRESS, Issue 4 2004Palle Komaraiah The use of a multisensor array based on chemical gas sensors to monitor plant cell cultures is described. The multisensor array, also referred to as an electronic nose, consisted of 19 different metal oxide semiconductor sensors and one carbon dioxide sensor. The device was used to continuously monitor the off-gas from two plant cell suspension cultures, Morinda citrifolia and Nicotiana tabacum, cultivated under batch conditions. By analyzing the multiarray responses using two pattern recognition methods, principal component analysis and artificial neural networks, it was possible to monitor the course of the cultivations and, in turn, to predict (1) the biomass concentration in both systems and (2) the formation of the secondary metabolite, antraquinone, by M. citrifolia. The results identify the multisensor array method as a potentially useful analytical tool for monitoring plant process variables that are otherwise difficult to analyze on-line. [source] Applications of electronic noses and tongues in food analysisINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2004Anil K. Deisingh Summary This review examines the applications of electronic noses and tongues in food analysis. A brief history of the development of sensors is included and this is illustrated by descriptions of the different types of sensors utilized in these devices. As pattern recognition techniques are widely used to analyse the data obtained from these multisensor arrays, a discussion of principal components analysis and artificial neural networks is essential. An introduction to the integration of electronic tongues and noses is also incorporated and the strengths and weaknesses of both are described. Applications described include identification and classification of flavour and aroma and other measurements of quality using the electronic nose. The uses of the electronic tongue in model analyses and other food, beverage and water monitoring applications are discussed. [source] DETECTION OF OLIVE OIL ADULTERATION WITH RAPESEED AND SUNFLOWER OILS USING MOS ELECTRONIC NOSE AND SMPE-MSJOURNAL OF FOOD QUALITY, Issue 1 2010SYLWIA MILDNER-SZKUDLARZ ABSTRACT The study analyzed the effectiveness of two types of electronic nose systems to detect adulteration of extra virgin olive oil (EVOO) with rapeseed and sunflower oils. Tested methods included volatile analysis with the electronic nose based on MOS sensors (HS-E nose) and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS. Samples of EVOO were mixed with different proportions, ranging from 5 to 50% (v/v), of seed oils and fingerprints of volatile profiles of all samples were generated. In order to obtain as much chemical information as possible and to find a volatile marker to detect adulterations of EVOO with seed oils, principal component analysis (PCA) and partial least squares (PLS) analyses were applied to the data. The application of PCA and PLS analyses to the data from two electronic noses and SMPE-GC/MS were sufficient to differentiate the adulterated samples from pure EVOO. Excellent results were obtained in the prediction of the percentage of adulteration by PLS analysis. SPME-GC-MS analysis with subsequent PCA yielded good results; however, it was time-consuming. The two electronic noses, with subsequent PCA treatment of data, offering the advantages of rapidity and reliability, enabled detection of olive oil adulteration with different contents of seed oils. PRACTICAL APPLICATIONS Virgin olive oil is highly appreciated by consumers due to its nutritional benefits. Thus, its adulteration with low-grade olive oils or cheaper vegetable oils could potentially be very profitable for sellers or raw material suppliers and may yield large economic profits. In this way, authentication of virgin olive oils has become an interesting subject from both commercial and health perspectives. It has been proved that the two proposed types of electronic nose systems facilitate reliable detection of rapeseed and sunflower oils in extra virgin olive oil. Both MOS and MS electronic noses are faster than the conventional SMPE-GC/MS analysis. These well-correlated methodologies, offering the advantages of rapidity and reliability, opened up a new way of detecting adulteration of virgin olive oils. [source] | |||||||||||||