New way of definition of an androstenon

By means of "an electronic nose" the problem of detection in salted pork fat of an androstenon is solved, even small concentration of which negatively affect consumer appeal of a product. The massif from eight differently selective gas sensors is applied to detecting of an androstenon. The massif is previously trained on easily volatile compounds of various classes (alcohols, ketones, water, nitrogen-containing connections). Significant differences in analytical signals of the massif of sensors at the maintenance of an androstenon in model test of salted pork fat at the level of 0.5 threshold limit values are established. Except an androstenon in crude salted pork fat also early signs of damage and also the overestimated moisture content are reliably fixed. Changes in test of salted pork fat at violation of storage conditions also authentically are registered a set of sensors though at the same time changes in color and a salted pork fat smell by tasters are not recorded. establishments of subtle differences in a smell of tests of salted pork fat are calculated parameters A (i/j) which are qualitative criteria of piezo-quartz microweighing. Parameters allow to identify in mix of substance and to track significant changes in structure of an equilibrium gas phase over tests. Responses of sensors with the modifiers sensitive to damage biomarkers are informative: alcohols, acids, ketones, nitrogen - and sulfur-containing connections while presence and the maintenance of an androstenon fix sensors with the modifiers sensitive to aromatic and cyclic hydrocarbons. A lot of the tests necessary for the analysis with double repetition did not exceed 5 g, measurement time – 60 with, the volume of an equilibrium gas phase of 5 cm3, an error – 10%. The analyzer of gases is reliable and easy-to-work.

Forecast of the direction changes of meat products odor in the development of new recipes according to the results of “electronic nose” data treatment with chemometric methods

The possibility of using new parameters of quartz crystal microbalance and methods of principal component analysis and discriminant analysis using regression to latent structures for processing the output data of piezosensors array for the detection of individual odor-forming compounds, quantitative assessment of odor properties in routine analysis, in the development of new recipes of food systems with the introduction of functional additives in the factory laboratories are discussed. Sorption of volatile organic compounds that make up the odor of meat products, on thin films of sorbents - modifiers of piezoelectric resonators electrodes, forming an array of sensors of gases analyzer "electronic nose" is studied. The resulting sensor array is trained on the main marker substances (distilled water, ethane, butyric acids, aliphatic alcohols (C2-C5) of normal and isomeric structure, dimethyl ketone, methyl ethyl ketone, alkyl acetates (C2-C5) methylpropionate). The effect of of water vapors as interfering factor in sorption of organic compounds was assessed. The parameters of the efficiency of volatile compounds sorption, allowing the identification of individual organic compounds or a class of similar to them in nature in gas mixtures were calculated. The use of discriminant analysis with regression to latent structures allowed the identification of individual organic compounds in the equilibrium gas phases over the real models for forecasting of change of direction of meat products odor with partial replacement of meat raw materials with functional preparations of plant origin (buckwheat and millet cereals, pickles of soybean and rapeseed protein) and products of microbial synthesis (preparation of yeast and wheat bran). For a detailed study of the changes in odor direction _ during the introduction of different amounts of cereals in the product the principal components method was applied. As the input parameters for the chemometric methods traditional analytical signal of the array of piezosensors - individual responses of measuring elements and the new - the parameter of sorption efficiency were selected. The results of gases analyzer processing data "electronic nose" with chemometric methods are consistent with the results of tasting the finished product by trained specialists

Development of express method of microgravimetric determination of actual resins in petrols

A new approach is proposed for a quick, simple assessment of one of the quality indicators of gasoline - the concentration of actual pitches. Separate standard quality indicators for the gasoline samples (with octane number 92), which are associated with the content of the components of petroleum fractions and other non-volatile compounds, were measured. The method of piezoquartz micro-weighting with one-sided loading of the resonant electrode of the resonator, sensitive on mass (OAB-type) with a limiting contour, is used. The correlation between the results obtained by piezoquartz micro-weighing and by the standard method was studied. Critical points of the developed method are determined - the stage of applying the exact volume of samples to the resonator electrode with a micro syringe. The method of molecular absorption spectroscopy in the middle UV region relative to hexane revealed differences in the composition of the components of the petroleum fraction of gasoline samples. The principle of comparing "fingerprints" is used to compare and establish the degree of identity of spectra and composition for gasoline samples from several characteristic points on the spectra. To find and evaluate the tightness of the connection between the results of different methods, a nonparametric method for small samples with the Spearman rank correlation was used. It is established that the values of the Spearman's correlation coefficients for the piezoquartz microweighting and the peak optical density present in all gasoline samples at the characteristic wavelength have a direct and strong tightness of the connection. The dependence of the signs is statistically significant, there is a close linear relationship between the parameters. The possibility of applying the piezoquartz micro-weighting method to develop an express method for estimating the non-volatile residue of gasoline was positively evaluated

The comparison estimation possibilities of intergal and differential gas analyzer with methodology of "electronic nose" for studing of meat products

продемонстрированы возможности интегрального («VOCmeter», Германия) и дифференциального («MAG-8», РФ) анализаторов газа с методологией «электронный нос» для количественной и качественной оценки легколетучей фракции ароматобразующих добавок, мясного сырья и мясных фаршей с добавлением функциональных препаратов.The possibilities of integral («VOCmeter», Germany) and differential («MAG-8», Russian Federation) gas analyzers with methodology of electronic nose for qualitative and quantitative estimation of volatile fraction of aromaforming additives, meat raw and half-finished products with functional additives have been demonstrated

The new instrumental methods for assesment organoleptic indicator of milk

Для сравнения состояния и технологии производства молока, наряду со стандартными показателями качества, применены инструментальные методы оценки запаха и цвета. Оценена информативность способа установления качественного и количественного состава равновесной газовой фазы над пробами молока анализатором «МАГ-8» с методологией «электронный нос» и определения цвета компьютерной цветометрией.To compare state and production technology of milk, the instrumental methods of assessment of smell and color are applied together with standard indicators of quality. The informative of the method of establishment qualitative and quantitative composition of equilibrium gaseous phase above samples of milk using analyzer MAG-8 with methodology electronic nose and determination color using computational colorimetric are estimated

The prevalence of the sleep disturbances among the patients with substance use disorders

Background. There is evidence that sleep disorders may be significantly linked to the development of the substance use disorders (SUD). However, data about the prevalence of the sleep disturbances among patients with SUD in Russia are relatively limited.Aim. To evaluate the frequency of the sleep disturbances among patients (n = 196) with alcohol (ÀD, n = 102), opioid (ÎD, n = 55) and polysubstance dependence (PD, n = 39) seeking addiction medical care.Materials and methods. We conduct a cross-sectional study of sleep disturbances among patients in St. Petersburg in 2017–2018. The modified Insomnia Severity Index (ISI) was administered to assess sleep during different periods of time: lifetime, the past 12 months, and the past 30 days.Results. All groups demonstrated relatively high presence of different sleep disorders (range: 49.0–76.5% among 196). The sleep disturbances over the past 30 days were more common in the AD group (60.8– 73.5% among 102) with the early morning awakening as the most frequent complaint. In the PD group the prevalence of lifetime sleep disturbances was high (94.9–100.0% among 39), whereas insomnia disorders were relatively rare over the past 30 days. However, it was sleep disturbances over the past 30 days that were statistically significantly more often (p < 0,05) observed in the group of patients who actively consume narcotic substances (40.2–87.2%), compared with the group of patients in remission (0–16.7%).Conclusion. The results demonstrated the high prevalence of insomnia among patients with SUD and suggested that the remission have a positive effect on the symptoms of sleep disorders. Further studies of the association between sleep disturbances and SUD progression are needed