| 1. |
- Bianchi, F., et al.
(författare)
-
Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis
- 2009
-
Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 77:3, s. 962-970
-
Tidskriftsartikel (refereegranskat)abstract
- The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene,o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.
|
|
| 2. |
- Comini, Elisabetta, et al.
(författare)
-
Metal oxide nanoscience and nanotechnology for chemical sensors
- 2013
-
Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 179, s. 3-20
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the capabilities and development prospects of nanostructured metal oxides (MOX) representing the most versatile and richest class of materials in terms of electronic structure and structural, chemical, and physical properties. MOX nano-materials with controlled composition, surface terminations, and crystalline structures to be used as chemical sensors as a new area in analytical chemistry and instrument engineering are discussed. Their principles of operation, and basic characteristics are outlined and main applications of MOX sensor technology are presented. © 2012 Elsevier B.V. All rights reserved.
|
|
| 3. |
- Concina, Isabella, et al.
(författare)
-
Early detection of microbial contamination in processed tomatoes by electronic nose
- 2009
-
Ingår i: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 20:10, s. 873-880
-
Tidskriftsartikel (refereegranskat)abstract
- Microbial contamination can easily affect processed tomato, thus determining both organoleptic adulterations and potential health risks for customers. Innovative techniques for a rapid and reliable diagnose of spoilage, such as electronic nose technology, are highly requested in order to guarantee food safety and to improve production. In this work canned peeled tomatoes were artificially spoiled with different kinds of microbial flora and then were analyzed by means of an electronic nose based on thin film metal oxide gas sensors. Preliminary analyses by dynamic-headspace gas chromatographic-mass spectrometry showed significant differences in the semi-quantitative volatile compounds profile of spoiled tomato samples just after few hours from contamination, thus suggesting to employ the electronic nose for an early diagnose of microbial presence. The electronic nose was indeed able to reveal contamination, even at early stages depending on the type of contaminant (e.g. for Saccharomyces cerevisiae and Escherichia coli), and to recognize spoiled tomato samples with good classification performances.
|
|
| 4. |
- Ponzoni, Andrea, et al.
(författare)
-
Nanostructured Metal Oxide Gas Sensors, a Survey of Applications Carried out at SENSOR Lab, Brescia (Italy) in the Security and Food Quality Fields
- 2012
-
Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 12:12, s. 17023-17045
-
Tidskriftsartikel (refereegranskat)abstract
- In this work we report on metal oxide (MOX) based gas sensors, presenting the work done at the SENSOR laboratory of the CNR-IDASC and University of Brescia, Italy since the 80s up to the latest results achieved in recent times. In particular we report the strategies followed at SENSOR during these 30 years to increase the performance of MOX sensors through the development of different preparation techniques, from Rheotaxial Growth Thermal Oxidation (RGTO) to nanowire technology to address sensitivity and stability, and the development of electronic nose systems and pattern recognition techniques to address selectivity. We will show the obtained achievement in the context of selected applications such as safety and security and food quality control.
|
|
| 5. |
- Sberveglieri, Giorgio, et al.
(författare)
-
Synthesis and integration of tin oxide nanowires into an electronic nose
- 2012
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:5, s. 532-535
-
Tidskriftsartikel (refereegranskat)abstract
- Single crystal nanostructures of semiconducting tin oxides have been fabricated and characterized as sensing materials for implementation in an electronic nose. The nanowires exhibit exceptional crystalline quality and a very high length-to-width ratio, resulting in enhanced sensing capability as well as long-term material stability for prolonged operation. A sensing device based on SnO2 nanowires has been fabricated and comparatively tested in an array of chemical sensor with conventional thin film sensing device. Preliminary measurements ethanol/water mixtures demonstrate that nanowire-based sensors can be favourably implemented in the electronic nose and that they perform comparably with the conventional thin film layers.
|
|
| 6. |
- Concina, Isabella, et al.
(författare)
-
Alicyclobacillus spp Detection in soft drinks by Electronic Nose
- 2010
-
Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 43:8, s. 2108-214
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper the skill of an electronic nose to early diagnose the natural contamination by Alicyclobacillus spp in commercial flavoured drinks is presented The instrument was able to identify contaminated products at very low bacterial loads (tens of copies/ml) with an excellent classification rate (almost 100%) The identification of Alicyclobacillus spp by means of the electronic nose was not based on the analysis of the secondary metabolites as it is done by classical analytical techniques thus allowing a surprising capability in recognising the contaminated products at early stage of growth This study strongly suggests the use of the Electronic Noses as screening tools in industrial quality control laboratories but at the same time it underlines some limits still present in the technology
|
|
| 7. |
- Concina, Isabella, et al.
(författare)
-
Electronic Nose : A Promising Tool For Early Detection Of Alicyclobacillus spp In Soft Drinks
- 2009
-
Ingår i: Olfaction and electronic nose. ; , s. 535-536
-
Konferensbidrag (refereegranskat)abstract
- In the present work we investigate the potential use of the Electronic Nose EOS835 (SACMI scarl, Italy) to early detect Alicyclobacillus spp in two flavoured soft drinks. These bacteria have been acknowledged by producer companies as a major quality control target microorganisms because of their ability to survive commercial pasteurization processes and produce taint compounds in final product. Electronic Nose was able to distinguish between uncontaminated and contaminated products before the taint metabolites were identifiable by an untrained panel. Classification tests showed an excellent rate of correct classification for both drinks (from 86% no to 100%). High performance liquid chromatography analyses showed no presence of the main metabolite at a level of 200 ppb, thus confirming the skill of the Electronic Nose technology in performing an actual early diagnosis of contamination.
|
|
| 8. |
- Concina, Isabella, et al.
(författare)
-
Electronic Noses As Flexible Tools For Evaluating Food Quality And Safety : Can We Trust Them?
- 2011
-
Ingår i: OLFACTION AND ELECTRONIC NOSE. - : AIP. ; , s. 109-110
-
Konferensbidrag (refereegranskat)abstract
- Since most food adulterations are reflected on volatile chemical profile, Electronic Noses (ENs) appear as excellent candidates for process monitoring, freshness evaluation, shelf-life investigation, sensory and authenticity assessment, microbial contamination diagnosis [1]. In this study three applications recently carried out in our laboratory are presented and discussed, with the aim to illustrate three paradigmatic and diverse issues related to food quality control in which EN can find application and discuss the reliability of sensor technology in food analysis.
|
|
| 9. |
- Concina, Isabella, et al.
(författare)
-
Electronic noses as flexible tools to assess food quality and safety : Should we trust them?
- 2012
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:11, s. 3232-3237
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents three different applications of an electronic nose (EN) based on a metal oxide sensor array, in order to illustrate the broad spectrum of potential uses of the technique in food quality control. The following scenarios are considered: 1) the screening of a typical error that may occur during the processing of tomato pulp, which leads to sensory damage of the product; 2) the detection of microbial contamination by Alicyclobacillus spp. (ACB) affecting soft drinks; and 3) the proof of evidence of extra virgin olive oil fraudulently adulterated with hazelnut oil. In each case, the EN is able to identify the spoiled product by means of the alterations in the pattern of volatile compounds, reconstructed by principal component analysis of the sensor responses.
|
|
| 10. |
- Gobbi, Emanuela, et al.
(författare)
-
Electronic nose and Alicyclobacillus spp. spoilage of fruit juices: An emerging diagnostic tool
- 2010
-
Ingår i: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 21:10, s. 1374-1382
-
Tidskriftsartikel (refereegranskat)abstract
- The application of an electronic nose equipped with a Metal Oxide Semiconductor sensor array for the detection of Alicyclobacillus acidoterrestris and A. acidocaldarius artificially inoculated in peach, orange and apple fruit juices is described in this study. Overall the system was able to detect the presence of Alicyclobacillus spp. in all the tested fruit juices at 24 h from inoculation. The electronic nose could detect bacterial concentration as low as <10(2) colony forming unit/ml and it was also able to classify bacterial contamination independently of the Alicyclobacillus species. The gas chromatography-mass spectrometry characterization of the volatile profile of orange juices confirmed the existence of quantitatively different patterns between contaminated and uncontaminated samples.
|
|
