METHODS OF IDENTIFICATION OF MUSCLE TISSUE IN MEAT PRODUCTS. PREREQUISITES FOR CREATING A MULTI–LEVEL CONTROL SYSTEM

Unfair production and products that do not comply with the declared labeling are currently an acute problem in the field of technical regulation, including with regard to food safety and quality. Given the high added value and multicomponent composition, finished meat products are among the most susceptible to adulteration. Despite the best efforts of regulatory agencies to counteract these inconsistencies, the hidden substitution of cheaper or lower-grade meats is still widespread. One of the main tasks facing research laboratories and testing centers today is the detection of falsification of food products, as well as standardization and certification of techniques necessary to solve such problems. The manufacturer, aware of the current control methods, can go to the deception, using vegetable protein, new unregistered feed additives. To determine the complex changes that occur in products, it is necessary to use methodological approaches in which it is possible to reliably determine these changes. The paper presents an overview of the most commonly used methodologies for assessing the component composition of meat products. Quality assessment of meat products includes control of components of finished products. The most difficult task is to determine the proportion of muscle protein in multicomponent meat products that have undergone heat treatment.Unfair production and products that do not comply with the declared labeling are currently an acute problem in the field of technical regulation, including with regard to food safety and quality. Given the high added value and multicomponent composition, finished meat products are among the most susceptible to adulteration. Despite the best efforts of regulatory agencies to counteract these inconsistencies, the hidden substitution of cheaper or lower-grade meats is still widespread. One of the main tasks facing research laboratories and testing centers today is the detection of falsification of food products, as well as standardization and certification of techniques necessary to solve such problems. The manufacturer, aware of the current control methods, can go to the deception, using vegetable protein, new unregistered feed additives. To determine the complex changes that occur in products, it is necessary to use methodological approaches in which it is possible to reliably determine these changes. The paper presents an overview of the most commonly used methodologies for assessing the component composition of meat products. Quality assessment of meat products includes control of components of finished products. The most difficult task is to determine the proportion of muscle protein in multicomponent meat products that have undergone heat treatment

ИДЕНТИФИКАЦИЯ И КОЛИЧЕСТВЕННОЕ ОПРЕДЕЛЕНИЕ МЫШЕЧНОЙ ТКАНИ НА ОСНОВЕ КОНТРОЛЯ ПРОТОТИПИЧЕСКИХ ПЕПТИДОВ С ИСПОЛЬЗОВАНИЕМ МЕТОДА МОНИТОРИНГА ЗАДАННЫХ РЕАКЦИЙ

One of the main problems of modern production of meat products is the quality of raw meat, which depends on various factors including genetic components, conditions of transportation, production and processing. The most important components of meat are proteins, the total content, structure and functional state of which in this complex biological system with many interacting components is constantly changing. In order to study the interspecific and intraspecific features of meat proteins, their transformations in the process of maturation and processing requires modern analytical technologies based on the systematic approach to the analysis. Proteomics, as a methodology for studying proteins in a certain system and at a certain time, opens wide opportunities in this direction, allowing to identify and develop accurate analytical methods for searching biomarkers and identifying unfair practices. Given the high added value and multicomponent composition, finished meat products are among the most susceptible to adulteration. Current paper presents a technique of high-performance liquid chromatography with mass spectrometric detector (HPLC-MS) adapted for the detection and quantification of two different types of meat (beef and pork) in a complex biological matrix such as structureless minced meat. After the protein isolation and trypsin cleavage, species-specific peptide markers were selected for each animal species for the quantification. The technique was tested on model samples of a mixture of muscle tissue of the two species of animals. A good sensitivity was established with the possibility of quantitative determination of muscle tissue of each animal species using special calibration graphs. The developed technique can find wide application at the supervising organizations aimed at counteracting the discrepancies in the hidden replacement of types of meat by cheaper or low-grade raw materials.Keywords: Biomarker, prototypical peptides, HPLC-MS, species identification(Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.4.012D.V. Khvostov1, N.L. Vostrikova1, A.V. Zherdev2, E.A. Zvereva2, A.A. Kurzova1  1V.M. Gorbatov Federal Research Center for Food Systems of Russian Academy of Sciences, 109316 Moscow, Russian Federation 2Federal State Institution «Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences», Leninsky prospect, 33, build. 2, 119071 Moscow, Russian FederationОдной из основных проблем современного производства мясных продуктов является качество мясного сырья, которое зависит от разных факторов, включая генетические составляющие, условия транспортирования, производства и переработки. К наиболее значимым компонентам мяса относятся белки, общее содержание, структура и функциональное состояние которых в составе этой сложной биологической системы, с большим количеством взаимодействующих составляющих, постоянно изменяется. Для изучения межвидовых и внутривидовых особенностей белков мяса, трансформации их в процессе созревания и технологической обработки требуются современные аналитические технологии, основанные на системном подходе к анализу. Широкие возможности в этом направлении открывает протеомика, как методологии изучения белков в определенной системе и в определенное время, позволяющая идентифицировать и разрабатывать точные аналитические методы поиска биомаркеров и выявления недобросовестных практик. Учитывая высокую добавленную стоимость и многокомпонентность состава, готовые мясные продукты относятся к числу наиболее подверженных фальсификации. В работе представлена методика высокоэффективной жидкостной хроматографии с масс-спектрометрическим детектором (ВЭЖХ-МС), адаптированная для обнаружения и количественного определения двух различных видов мяса (говядина и свинина) в сложной биологической матрице, такой как бесструктурные фарши. После выделения белков и расщепления их трипсином были выбраны видоспецифичные пептидные маркеры для каждого вида животного с целью количественного определения. Методика была апробирована на модельных образцах смеси мышечной ткани двух видов животных. Установлена хорошая чувствительность с возможностью количественного определения мышечной ткани каждого вида животного, при использовании специальных градуировочных графиков. Разработанная методика может найти широкое применение у контролирующих организаций, направленных на противодействие несоответствиям по скрытой замене видов мяса более дешевым или низкосортными сырьем.Ключевые слова: Биомаркер, прототипические пептиды, ВЭЖХ-МС, видовая идентификацияDOI: http://dx.doi.org/10.15826/analitika.2019.23.4.01

Matrix Correction Minimal with respect to the Euclidean Norm of a Pair of Dual Linear Programming Problems

Abstract. The paper presents problem formulations, theorems and illustrative numerical examples describing conditions for the existence and a form of solutions of the problem of matrix correction minimal with respect to the Euclidean norm of a pair of dual linear programming (LP) problems. The main results of the paper complement classical duality theory and can serve as a tool to tackle improper LP problems, and/or to ensure the achievement of prespecified optimal solutions of the primal and dual problems via the minimal with respect to the Euclidean norm correction of the constraint matrix elements, the right-hand sides of the constraints and the objective functions of the original problems. Keywords: dual pairs of linear programs, improper linear programs, the minimum matrix correction, the Euclidean norm

A new hard allotropic form of carbon: Dream or reality?

Abstract An unusual phase of carbon with the fcc crystal structure, the lattice constant of which is very close to that of diamond, was reported before in a number of publications. In all the published works, the existence of fcc carbon could not be unambiguously established, as only insignificant amounts of fcc carbon in mixture with other carbon modifications were obtained so far. The present work provides for the first time clear evidence for the existence of the carbon modification with the fcc crystal structure. Thin films consisting exceptionally of fcc carbon were obtained by various methods, namely by hot-filament CVD, plasma-assisted CVD and treatment of the diamond surface in hydrogen plasmas. Results of electron diffraction, Raman spectroscopy, AES, XPS, EELS and HRTEM of the films consisting of fcc carbon clearly indicate its unique crystal and electron structure. The micro-hardness of the films of fcc carbon was found to be equal to HV 0.01 = 250 which is quite different from the hardness of all the known carbon modifications

Reduction of hepatotoxicity of nimesulide in mechanochemically obtained composition with disodium salt of glycyrrhizic acid

Nimesulide (NIM) is a nonsteroid anti-inflammatory drug which acts as a selective cyclooxygenase 2 inhibitor and is widely used for acute pain treatment. In medical practice, a large amount of data has been collected describing the effect of NIM on the body, while a hepatotoxic side effect of the drug has been found. The exact mechanisms of such NIM-induced hepatotoxicity largely remain unknown but likely involve the intermediate reaction of its metabolism. Reduction of the hepatotoxic side effect of NIM is an actual problem for pharmacology. The aim of the present research was to evaluate the hepatotoxicity of the mechanochemically obtained composition of NIM with glycyrrhizic acid disodium salt (Na2GA) compared to pure NIM and a physical mixture of NIM with Na2GA. Material and methods. CD-1 mice were orally administered for 14 days: 1 group – mechanochemical composition NIM/Na2GA (1:10, m/m) at a dose of 1650 mg/kg; 2 group – physical mixture of NIM with Na2GA (1:10, m/m) at a dose of 1650 mg/kg; 3 group – pure NIM at a dose of 600 mg/kg (which pharmacokinetically corresponds to 1650 mg/kg of NIM/Na2GA); 4 group – vehicle (distilled water). The liver damage was assessed using histological studies and enzymatic activity of the alanine aminotransferase and aspartate aminotransferase in blood serum. Results. Histological analysis did not detect any changes in the liver of NIM/Na2GA-treated animals in comparison with a water-treated group. On the opposite, NIM given alone or as a physical mixture with Na2GA induced severe hepatotoxicity in experimental mice. Biochemical analysis of the blood serum revealed that mechanochemical NIM/Na2GA composition significantly reduced activity of the alanine aminotransferase (about 1.5 times) and aspartate aminotransferase (1.3 times) as compared with the pure NIM. Conclusions. The results obtained indicate a high potential for the practical application of the NIM/Na2GA mechanochemical composition

Use of perovskite in solar energy

The article examine relatively new material for solar energy – perovskite. It dealt with physical properties. Data are given about developments in this field Russian and foreign scientists. It is analyzed coefficients of efficiency used in industry materials.В статье рассмотрен относительно новый материал для солнечной энергетики – перовскит. Дано описание его физических свойств, приведены разработки в этой отрасли как российских, так и зарубежных ученых. В работе проведен сравнительный анализ материалов для изготовления солнечных элементов по коэффициентам полезного действия

The morphofunctional and biochemical characteristics of opisthorchiasis-associated cholangiocarcinoma in a Syrian hamster model

The validity of experimental models of pathologies is one of the key challenges in translational medicine. Cholangiocarcinoma, or bile duct cancer, ranks second among oncological diseases of the liver. There is a strong association between bile duct cancer and parasitic infestation of the liver caused by trematodes in the family Opisthorchiidae. We have recently demonstrated that cholangiocarcinoma can develop in Syrian hamsters (Mesocricetus auratus) infected by Opisthorchis felineus and administered with dimethylnitrosamine. However, there is still no description of how this experimental model can possibly be used in translational research. The aim of this work was to study the morphological, functional and biochemical characteristics during cholangiocarcinoma development in Syrian hamsters infected by O. felineus and administered with dimethylnitrosamine. The experi­ment lasted 30 weeks with combined exposure to dimethylnitrosamine in drinking water at a dose of 12.5 ppm and a single injection of 50 metacercariae O. felineus. It was shown that the development of cholangiocarcinoma (18 weeks) increased the total number of basophils, eosinophils and monocytes, the relative number of granulocytes, the amount of total and direct bilirubin, and cholesterol and ALT levels, but reduced the relative number of lymphocytes. Based on pathological, morphometric and biochemical analyses, our model has characteristics similar to those in patients with opisthorchiasisassociated cholangiocarcinoma. Thus, this model can be used to test anticancer drugs, to study the mechanisms of cholangiocarcinogenesis and to search for molecular markers for early diagnosis of bile duct cancer

INVESTIGATION OF STEEL CORROSION RATE IN MOLTEN SALTS USING NEUTRON ACTIVATION METHOD

The paper gives experimental results of investigation of EP-823 steel corrosion in molten salts using neutron activation method. Unoxidized and thermally oxidized in the air to ~12.5 μm thick oxide film EP-823 steel samples, irradiated in IVV-2M reactor to neutron fluence of ~2.9·1017 n/cm2, underwent static corrosion tests in KCl-LiCl and KCl-LiCl-nPbCl2 molten salts at 500 and 650 °С during 24 h. It shows that corrosion and corrosion product transfer to molten salts are selective in terms of steel elements

Automation of recognition of chemicals using electronic sensor technology based on neural network data processing

The composition of the initial substance was determined using an electronic sensor “electronic nose”, consisting of 8 sensors, to which air was supplied with a syringe with alcohol vapor containing various kinds of impurities. The signal from the sensors was recorded with a sampling frequency of 1 s for 120 s. The output of the device was presented in two different interpretations - in the form of curves obtained from each sensor, or the areas under the curves. The purpose of the work is to build a recognition system for 11 impurities and water in the starting material. The composition of the initial substance was determined using an “electronic nose”, which allows one to obtain 120 values from each of 8 sensors in the form of curves or the values of the areas under the curves. A large number of classes (12), the dynamic presentation of the source data information make it advisable to build a pattern recognition system based on a neural network - a multilayer perceptron trained on the basis of the error back propagation algorithm. When training the network, existing samples are used, indicating which class they belong to. The properties of each analyte are represented as a vector of 120 values of 8 attributes defining one of 12 classes. To reduce the dimensionality of the input data of the neural network, the authors proposed the use of convolution of the available information without significant loss of information capacity of signs by constructing 8 polynomial regressions of the 19th order that describe the curves from each of the 8 sensors of the “electronic nose”. The input matrix obtained as a result of convolution consisted of 20 polynomial regression coefficients of each of 8 curves for 12 classes under consideration. A two-layer neural network with 43 neurons and a sigmoidal activation function in the hidden layer and 12 neurons and a linear activation function in the output layer was constructed. As a result of network training, 2 classification errors were obtained, which allows us to use the approach proposed by the authors to build a recognition system based on preliminary convolution of data dynamically obtained from the “electronic nose