The new approach to a pattern recognition of volatile compounds: the inflammation markers in nasal mucus swabs from calves using the gas sensor array

This paper discusses the application of two approaches (direct and inverse) to the identification of volatile substances by means of a gas sensor array in a headspace over nasal mucus swab samples taken from calves with differing degrees of respiratory damage. We propose a unique method to visualize sensor array data for quality analysis, based on the spectra of cross mass sensitivity parameters. The traditional method, which requires an initial sensor array trained on the vapors of the individual substances (database accumulation)-with their further identification in the analyzed bio-samples through the comparison of the analysis results to the database-has shown unsatisfactory performance. The proposed inverse approach is more informative for the pattern recognition of volatile substances in the headspace of mucus samples. The projection of the calculated parameters of the sensor array for individual substances in the principal component space, acquired while processing the sensor array output from nasal swab samples, has allowed us to divide animals into groups according to the clinical diagnosis of their lung condition (healthy respiratory system, bronchitis, or bronchopneumonia). The substances detected in the gas phase of the nasal swab samples (cyclohexanone, butanone-2,4-methyl-2-pentanone) were correlated with the clinical state of the animals, and were consistent with the reference data on disease markers in exhaled air established for destructive organism processes

E-nose for the monitoring of plastics catalytic degradation through the released volatile organic compounds (VOCs) detection

The work presents the results of an artificial olfaction E-nose system application for detection of Volatile Organic Compounds (VOCs) – destruction products of OXO-biodegradable polyethylene films when exposed to Ultraviolet (UV) irradiation and heating. The E-nose system was based on eight piezoelectric quartz resonator sensors coated with polymeric sensing materials with various selectivity to analytes. The effect of prooxidants, materials based on variable valence metals, such as D2w, ferric stearate and ferric carboxylate, addition on polyethylene films (PE) photo destruction was studied. The dependence of the composition of VOCs mixtures emitted by PE films on the processing time, the power of the UV irradiation and on the nature of the modifying additive was established. In addition, the main emitted volatile compounds were identified and the dynamics of their formation for different catalysts during the plastics destruction were studied. The proposed E-nose system has proved to be an effective tool for assessing catalyst-prooxidants properties. © 2020 Elsevier B.V

Electronic taster applied for identification of a rainbow trout spoilage specifics

The research is aimed at the study of control possibilities of freshness degree and storage technology violation of frozen fish (Rainbow trout) using chemical piezo sensors array in the «e-nose» system. There have been demonstrated the opportunities of qualitative and quantitative determination of priority highly volatile compounds-markers of native and modified state of fish and gills after a 2-minute measuring by sensors array with minimal sample preparation and without additional preparation or odour components concentration. We can fixate early signs of changes in the fish fillet of a trout after three days of storage mode non-compliance and subsequent freezing, using chemical sensors. We can evaluate the storage time of fresh fish in any conditions with an error of measurement of no more than 10 %. We have developed the method of fish odour simple analysis and of obtaining diagnostic information about fish freshness according to fillet and gills state. The application mode of chemical sensors and e-nose «MAG-8» allows acquiring objective information, and is highly sensitive, expressive and economically acceptable for laboratories and mobile monitoring stations of any level

Study of the chemical composition of the smell of the dairy-vegetable extract of lupine on the “Piezoelectronic nose”

A great popularity in the food industry in recent years has received lupins due to a unique combination of technological and food properties and accessibility. Lupine is characterized by a high proportion of proteins, its seeds are dominated by readily soluble protein fractions: 20.65% albumins, 50.5% globulins with a high content of essential amino acids. Enrichment of the milk-vegetable extract with native components of lupine is carried out during extraction with intensification by its low-frequency mechanical oscillations. The high content of proteins in the lupine during processing leads to a negative technological change in the organoleptic properties of products - odor. The measurement of the composition of the volatile fraction of odor in the equilibrium gas phase over the samples was carried out in the NIL on the experimental analyzer of smells "MAG 8" with the methodology "electronic nose" (manufactured by LLC Sensorika - New Technologies, Voronezh). To establish the differences in the composition (qualitative and quantitative) of the volatile fraction of smell, the change in the total content of volatile components in the equilibrium gas phase over the samples was traced. According to the shape of the "visual fingerprint" of the maximum responses of all sensors in the array, there are no significant differences in the chemical composition of the equilibrium gas phase over the samples. The native smell of milk whey remained unchanged, but became more qualitatively softer with a tasting assessment due to the fact that 50% of the composition of the volatile fraction of odor was changed by the method of pasteurization. The study of the smell of the native and pasteurized milk and vegetable extract allows us to conclude that the chosen method of pasteurization can be recommended in food technology using a milky-vegetable extract enriched with lupine proteins