38 research outputs found

    DETERMINATION OF DIFFUSION COEFFICIENTS OF EXTRACTIVES IN LUPINE

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    Summary. The work is presented by two sections: theoretical and applied. In the first section the equation for calculating concentration fields is given. To obtain additional physical information about the process the initial and boundary conditions were recorded. The equation which is the generalised theoretical decision for various geometrical forms of a material is resulted: a sphere, an unlimited cylinder and an unlimited plate. Taking into account the extracting conditions the expressions were written the attractiveness of which is in their suitability for the calculation of the mass flow of the target components of the capillary with a known surface area. The presented theoretical data gave the chance to obtain the equations for calculation of diffusion factors in the material (forms: a sphere, an unlimited cylinder, an unlimited plate). The intuition prompts that these equations are fair for all kinds of raw materials of the plant origin with the capillary porous structure as follow from the base equation which was written down by G.A. Akselrud and V.M. Lysiansky. So diffusion factors, for example, were calculated at the extraction by liquid carbon dioxide from barley grains, acorn fruits and chicory roots crushed into grains and petal. The applied part of work is devoted to the calculation of diffusion factors in a lupine at the extraction by cheese whey and to the analysis of results, using for this purpose experimental data on the kinetics of the process, background in quantitative interpretation was formulated. For example, the lupine particles had the form of a sphere, a cylinder and a plate and as one of their sizes exceeds each of remained in four or more times so the particles can be considered as unlimited bodies. Therefore, one-dimensional diffusion flux towards the minimum size takes place in them. The results of diffusion factors calculations for all forms of material are presented by schedules from which it is obvious that the curves are close to each other and it is possible to present them with one generalised equation D( ). The quantitative evaluation of the results is given. One value of diffusion factor is also received, for this purpose the angular coefficient of the straight section being the area of the regular mode was determined. The conclusion is made that the researches carried out do not contradict to modern representations about the extracting mechanism

    Influence of citric acid on thermoplastic wheat flour/poly (lactic acid) blends. II. Barrier properties and water vapor sorption isotherms

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    The effects of citric acid on wheat flour/glycerol/poly(lactic) acid (PLA) blends prepared by one-step twin-screw extrusion have been studied to improve barrier properties of starch based materials. A series of injected samples were produced from prepared compounds with varying ratio (0-20 part) of citric acid. The effects of citric acid on the water vapor permeability, oxygen permeability and water solubility in the film were then investigated. The barrier properties results proved that citric acid behaves as compatibilizing agent between starch and PLA phases for ratios between 0 and 10 parts. When the added amount exceeds 10 parts, CA acted as a plasticizer and/or promoted the hydrolysis of the starch glycosidic bonds

    Quantitative estimates of unique continuation for parabolic equations, determination of unknown time-varying boundaries and optimal stability estimates

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    In this paper we will review the main results concerning the issue of stability for the determination unknown boundary portion of a thermic conducting body from Cauchy data for parabolic equations. We give detailed and selfcontained proofs. We prove that such problems are severely ill-posed in the sense that under a priori regularity assumptions on the unknown boundaries, up to any finite order of differentiability, the continuous dependence of unknown boundary from the measured data is, at best, of logarithmic type

    CREATION OF MATHEMATICAL MODEL OF EXTRACTION BY CHEESE WHEY FROM A LUPINE IN THE FORM OF A PLATE

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    Prerequisites for creation of model are stated. At a problem definition consideration of a particle of a lupine as unlimited plate is proved. The main assumptions are formulated, regional conditions are written out. Partial solutions of the differential equation, and also the common decision for the current value of a concentration pressure С'(x,у). Distribution of concentration is symmetric concerning ordinate axis. Final expression for a field of concentration at extraction of a flat plate in a dimensionless look is written out. It is shown that distribution of concentration is rather precisely described by the first member of a row. Th e conclusion is drawn that for any timepoint under the set boundary conditions the field of concentration has an appearance of a symmetric curve with a maximum on a plate axis (Х=0). For each subsequent timepoint there will be the curve which is monotonously decreasing to a plate surface. It is proved that it is possible to define nature of change of concentration in a body at a preset value the case when strives for infinity at the set physical parameters, thickness of a plate and the organization of high intensity of branch of extractive substances from a surface Is considered. For this case the equations of rather dimensionless concentration and Fourier's numb er are received. Also the equation for definition of final time of extraction is written out. It is shown that the received solutions of the eq uations of model are found in a good consent with experimental data

    Ill-posed problems of mathematical physics and analysis

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    OPTIMIZATION OF PROCESS EXTRACTION OF LUPINE CHEESE WHEY

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    The urgency of the job is showed. These words of the academician A.G. Khramtsov that breakthrough technology in the dairy industry is the use of whey as a solvent for the extraction of target components of plant raw materials and obtaining valu-able milk-plant extract. The problem of optimization to determine the input factors for the effective management of process of extraction. Optimization of parameters of the process was carried out experimental-statistical methods in several stages. At the first stage built regression model that adequately describes the dependence of the selected output parameter from the studied factors. A full factorial experiment (PFA) type 23, composed planning matrix, decorated in a table. The experiments were conducted in a double-repetition. The number of experiments in the centre of the plan selected taking into account a possible transition to the planning of the second order. The plan PFA type 23 gives the possibility to calculate 8 regression coefficients and construct the equation of the first order. The results of calculation of confidence errors presented in the table. Statistical processing of experimental data allowed determining the regression coefficients, check their significance, to assess the reproducibility of experiments and to establish the adequacy of the obtained regression equations of the second order on three criteria. The second stage was to optimize the parameters of extraction. Statement of a problem of optimization recorded analytically. To solve this problem we use the method of the Lagrange multipliers. According to calculated by the algorithm is composed of a system of equations containing partial derivatives of the objective function for all independent variables and undetermined Lagrange multiplier. Optimal recognized the results obtained on the 10-step optimization, providing the maximum output of extractive substances. The obtained optimal conditions of extraction. The third stage was to evaluate the precision and reliability of the obtained values of the optimization criterion (output of extractive substances)

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

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    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

    PRACTICAL PROPOSALS AS A RESULT OF THEORETICAL AND EXPERIMENTAL STUDIES OF THE PROCESS OF EXTRACTION FROM RAW MATERIALS OF PLANT ORIGIN

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    Summary. Theoretical and experimental researches of extraction processes from plant origin raw materials: barley, acorns and chicory with liquid carbon dioxide, as well as lupin with cheese whey were carried out. Quality indicators of extracts and secondary raw materials are defined. It is established that they are perspective raw sources for the enriched and functional products as they contain amino acids, vitamins and microelements. The dairy-vegetative lupine extract, for example, contains 17 amino acids, including the essential as well as vitamins and minerals. The studies of secondary raw materials, barley, acorns, chicory and lupine quality showed the expediency of their use for foods enrichment. Quality indicators of secondary raw materials are presented in the tables form in the given work. It formed the basis for the development of hardware-technological schemes of obtaining СО2-extracts and their use. The hardware-technological scheme of obtaining СО2-extracts from barley, acorns and chicory includes a number of equipment units: motor transport for raw materials delivery to the enterprise, the scraper hydroconveyor, the jet washer, a photoseparator for of poor-quality raw materials and impurities removal, a blowing machine for removing surface moisture from the raw materials, a jet washer for peeling, a cutter, drying and frying device, a crusher, a roller machine tool and an extracting unit. Hardware providing for yoghurt technology enriched with amino acids, microelements and vitamins which are present in a dairy-plant extract differs from the mentioned above one in the following. The extract used is a cheese whey, and the extraction of a target component is carried out in a vibrating extractor. The hardwaretechnological scheme is made according to Russian technology of yoghurt and furnished with the equipment for dairy-vegetative extract feeding into a product. It includes the following: a vibrating extractor (not shown in fig. 2), the extract collector, the cover and tube heat exchanger and the refrigerator. Prerequisites reconditions are stated at a heat exchanger choice. The offered scheme can be used in the manufacture of other fermented milk products. Thus, the hardware-technological schemes developed by the authors contribute to the complex processing of secondary raw materials of plant origin which is economically and ecologically expedient
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