Drying Mode Research Articles

Импульсная сушка заготовок из древесины красного и черного дерева в конвективных сушильных камерах

A review of literature sources on the physical and mechanical properties of redwood and ebony is given. A description of the characteristic properties of redwood and ebony wood is given. The place of growth of these species, varieties of properties depending on the area of their distribution are indicated. A review of literature sources on regime parameters for drying redwood and ebony wood blanks is given. The drying modes are given, which depend on the current moisture content of the wood and differ from each other in the initial and final temperatures, as well as the degree of saturation of the drying agent at the initial and final stages of drying. The principles of the structure of pulse modes of wood drying are considered. The modes of pulsed drying of redwood 50 mm thick and ebony 25 mm thick blanks are presented. The initial moisture content of mahogany and ebony blanks was determined according to GOST 16588. The control over the current moisture content was carried out by the method of control samples. And the development of drying stresses is based on power samples. The stresses arising during the drying of the workpieces were evaluated by the relative deformation of the power sections teeth, sawn from the control power samples. The use of pulsed modes allows you to reduce energy consumption and improve the drying quality.

Effect of Three Drying Modes on Nutritive and Antinutritive Properties of Leafy Vegetables Consumed in Northern Côte d’Ivoire

In tropical Africa, leafy vegetables are traditionally eaten as a relish together with a starchy staple food. Nevertheless, report on their nutritive potential is scanty. In order to contribute to their valorization, leafy vegetables consumed in the north of Côte d'Ivoire (Cerathoteca sesamoides, Leptadenia hastata, Ocimum gratissimum and Portulaca oleracea) were studied. The leafy vegetables were collected in the towns of Korhogo and Dabakala located respectively in the North and Center-North of Côte d'Ivoire. These sheets were subjected to three drying treatments before their characterization. To do this, the physico-chemical and nutritional properties of these leafy vegetables have been realized. The results revealed that oven and sun drying significantly reduced the moisture in our four leafy greens. After drying, C. sesamoides and O. gratissimum had the lowest moisture content of 8.25±0.15% and 8.07±0.06% respectively for oven drying, while sun drying reduced these moisture levels to 9.48±0.12% and 9.23±0.1% respectively for the leaves of C. sesamoides and O. gratissimum. Unlike humidity, these analyzes revealed a concentration of ashes, proteins, fibers and carbohydrates during the three drying modes. With regard to the ashes, drying in an oven allowed a better concentration in the leaves of L. hastata (13.40±0.04%) and P. oleracea (21.81±0.50%) while drying in the sun gave a content of 18.24±0.33% (P. oleracea) and that of shade drying recorded a content of 13.26±0.13% (L. hastata). Concerning the protein content, the results obtained showed that the leaves of C. sesamoides, L. hastata and O. gratissimum had a better concentration during drying in the oven and in the shade. Oven drying recorded a protein content of 22.01±0.08% (L. hastata) and 22.65±0.08% (O. gratissimum) while shade drying recorded a protein content of 22.67±0.10 % (L. hastata) and 23.62±0.46% (C. sesamoides). At the level of crude fibers, the results showed that the leaves .............

ДОСЛІДЖЕННЯ ЯКОСТІ СУШІННЯ ЗЕРНА КУКУРУДЗИ СУШАРКОЮ МОДЕЛІ STELA AGRODRY MDB-XN 4/15-SU В ЖОРСТКОМУ РЕЖИМІИ

ДОСЛІДЖЕННЯ ЯКОСТІ СУШІННЯ ЗЕРНА КУКУРУДЗИ СУШАРКОЮ МОДЕЛІ STELA AGRODRY MDB-XN 4/15-SU В ЖОРСТКОМУ РЕЖИМІИ

Experimental research on the development of the composition of the transdermal therapeutic system of anti-inflammatory action based on composition of natural substances

The aim of the work is to develop the composition of the transdermal therapeutic system of anti-inflammatory action based on active pharmaceutical ingredients of natural origin. Materials and methods. Selection of adhesive materials, plasticizers and solvents, the effect of introduction to the base of active pharmaceutical ingredients, determination of optimal temperature and drying time, pharmacological screening was performed by physicochemical, biopharmaceutical and biological research methods. Results. The composition of the hydrophilic adhesive composition, which includes polyvinylpyrrolidone, eudragit (adhesives), PEO-400 (plasticizer), isopropyl alcohol (solvent) 50: 8: 12: 30, respectively. This composition has excellent organoleptic properties, is easily applied to the polymer base, holds its shape well (does not flow beyond the base), is applied in a thin layer and evenly distributed on the base. The optimal mode of drying of the adhesive composition based on PVP is 75 °C for 30 min, based on PVA – 75 °C for 35 min, the composition containing eudragit - 50 °C for 10 min. It is established that the addition of active substances to the adhesive composition does not adversely affect its properties. The study of antiexudative activity using different combinations of substances of natural origin as API and found that the best anti-inflammatory properties (25 %) have a sample No. 4, which includes dry extracts of white willow bark and sage leaves and quercetin 3:1:3 in accordance. Conclusions. Based on physicochemical, biopharmaceutical and pharmacological studies, the composition of the transdermal therapeutic system of anti-inflammatory action with active pharmaceutical ingredients of natural origin has been developed

Applications of solar energy for drying of agricultural commodities

Drying is a simultaneous heat and mass transfer energy intensive operation, widely used as a food preservation technique. In view of improper postharvest methods, energy constraint and environmental impact of conventional drying methods, solar drying could be a practical, economical and environmentally reliable alternative. Open air solar drying method is used frequently to dry the agricultural products. But this method has some disadvantages. Therefore, to avoid disadvantages it is necessary to use the other solar drying methods. Different solar drying methods are direct solar drying, indirect solar drying and mixed mode solar drying. The device used for drying process with application of solar energy called the solar dryer. Solar dryer are also classified with mode of air circulation. In this paper, we studied the various modes of solar drying and classification of solar drying techniques.

Investigation of gas-solid heat and mass transfer in a Wurster coater using a scaled CFD-DEM model

Detailed knowledge about the gas-solid heat and mass transfer is essential for the design and optimization of the fluidized bed coating process. Coupled computational fluid dynamics and discrete element method (CFD-DEM) is a powerful tool to understand such a process. However, in previous CFD-DEM studies, the inter-phase heat and mass transfer appeared to be substantially simplified or even neglected. In this work, a complete and reliable CFD-DEM model is proposed to investigate the Wurster coating process. Considerable attention is paid to numerical methods on the particle-fluid heat convection, coating liquid spraying and the evaporation of sprayed liquid on the particle surface. To allow the simulation of coating processes with many particles in an acceptable runtime, a novel scaling approach accounting for the interphase heat and mass transfer is proposed. The proposed CFD-DEM model is then validated by the simulation results under different scaling degrees and the temperature/humidity data in experiments. The simulations reveal three modes of particle drying in the coating process, and multiple humidity probes mounted along the vertical direction of the annulus region would be helpful to predict the over-spraying in advance. The proposed methodology can be extended to the spouted and top-spray beds.

Analysis and modelling of temperature and moisture gradient for ginger slices in hot air drying

To understand the temperature and moisture distribution of ginger slices during hot air drying, mathematical models were developed to simulate the heat and mass transfer in various drying modes, including constant hot-air drying modes (the drying temperatures were kept at 50, 60, 70, 80 °C, respectively) and multistage drying modes (the drying temperature was varied between 50 °C and 80 °C during a single drying process). The simulation results showed that the developed models fitted the experimental data well, which proved their effectiveness in various drying modes. The three-dimensional temperature and moisture distribution models also demonstrated that the low temperature gradient between the surface and the core had little effect on the drying results. In the case of a high drying temperature, the core part contained high moisture content even after drying. Among all drying modes, the L-H-L (the drying temperature was increased from 50 °C to 80 °C and then to 50 °C again) was the best if the maximum moisture difference during the drying process and the final moisture difference between the surface and the core were all considered. For the final product quality, this drying mode also performed well and resulted in a higher rehydration ratio, better microstructure, less color difference, higher total gingerol content, and good sensory evaluation. Therefore, it was necessary to keep the air temperature at a low level at the beginning and final stages for the quality and storage safety consideration. While in the middle stage, the drying temperature could be increased to a higher level to accelerate the drying speed.

Thin Layer Modelling of Indirect and Mixed-Mode on-Farm Drying of Selected Vegetables

The thin layer drying characteristics of tomato and okra slices dried using mixed-mode on-farm solar dryer, indirect mode on-farm solar dryer and open sun drying. The tomato and okra slices dried faster when dried under the mixed-mode on-farm solar dryer. Drying time was reduced considerably using the on-farm solar dryers. The drying data were fitted into Lewis, Henderson and Pabis, and page equations. The Page model (R2=0.9365, 0.9623; X2= 0.0067, 0.0000579; RMSE= 0.0086, 0.0020 and MBE= -0.008, -0.002) gave the best prediction for the mixed-mode drying and indirect mode drying of tomato slices respectively. In the same vein Page model (R2=0.9202, 0.933o; X2= 0.00091, 0.000730; RMSE= 0.0265, 0.0244 and MBE= -0.0088, -0.0074) gave the best prediction for the mixed-mode drying and indirect mode drying of okra slices respectively. Effective moisture diffusivity of tomato slices varied between -7.4724 X 10-08 and -1.6439 X 10-07 while that of okra varied between -3.12 X 10-07 and -8.08 X 10-07. The indirect mode dryer gave the best quality of dried tomato and okra.

Импульсная сушка пиломатериалов из древесины грецкого и американского черного ореха в конвективных сушильных камерах

A review of the literature on the physical and mechanical properties of the walnut and the scope of its application is presented. Pilot drying of walnut wood with a thickness of 50…60 mm was carried out in modernized drying chambers using impulse drying modes URAL-72 at INTAR LLC, Moscow. An example of an impulse drying mode for a walnut with a thickness of 50…60 mm is given. The initial moisture content of wood was determined in accordance with GOST 16558–91. The physical and mechanical properties of American walnut are outlined. The drying mode of American walnut 32…35 mm thick included 9 steps. The temperature of the drying agent is from 49 °C to 83 °C. The degree of saturation of the drying agent is from 79 to 31 %. Impulse drying of American walnut wood with a thickness of 32…35 mm was carried out in a pilot drying tunnel at the Department of Wood Science and Woodworking Technology of Moscow State Forest University. The initial moisture content of American walnut wood was determined in accordance with GOST 16588–91. The control over the current moisture content and internal stresses in the wood of walnut and American black walnut during drying in impulse modes was carried out using the method of control samples. Determination of the quality of dried timber was carried out in accordance with the «Guiding technical materials on the technology of tunnel drying of sawn timber» and the technical conditions of GOST 2695–83. The use of impulse modes when drying walnut and American walnut wood allows saving from 30 to 50 % of electricity.

Influence of adding wild berry powders on the quality of pasta products

Pasta is a popular food item among consumers all over the world. They have high energy value, low cost and long shelf life. However, the biological value of these products is quite low. Adding components rich in dietary fiber, vitamins and minerals to their composition will significantly improve their nutritional value. The purpose of the article is to analyze the possibility of producing pasta with the addition of derivatives from the processing of wild berries Sambucus nigra, Viburnum opulus, Hippophae rhamnoides L., which have a rich nutrient composition and are available raw materials. The technology, developed in the work for processing berries by osmotic dehydration, allows the use of gentle drying modes, which contributes to the maximum preservation of their biological value. Sensory evaluation of pasta was carried out according to the Croatian Official Methods, moisture content of pasta was determined by drying to constant weight. Sensory analysis of pasta showed that the addition of powders does not lead to a deterioration in their quality. Their appearance, taste, smell, shape and elasticity are improved. The quality of the pasta samples, containing 5 % of the powder, was determined as “good” according to the results of the evaluation of the tasting group. And the samples with a powder content of 10 % have a "high" quality. The addition of powders has practically no effect on the drying conditions and moisture content of the finished products. With the addition of Viburnum opulus powders, the moisture content is reduced compared to controls. Humidity of all samples is within the permissible limits, which indicates their resistance to storage

Design and Development of Hot Air-assisted Continuous Infrared Drying System for Shrimps

ABSTRACT The study was aimed to develop a hot air (HA) assisted continuous infrared radiation (IR) drying system and dry the shrimp samples under HA mode (45 °C, 1.5 m/s), IR mode (4500 W, 1.5 m/s), and a combination of IR-HA mode (4500 W, 45 °C, 1.5 m/s). The shrimp samples attained a final moisture content of 15.12%, 11.66%, and 11.98% (w.b) and drying efficiency of 8.78%, 15.65%, and 36.25% under the HA, IR, and IR-HA mode of drying in 21.5 h, 3 h, and 2 h, respectively. In this study, the IR-HA mode of drying of shrimp was found to be efficient with the lowest drying time of 2 h, the specific energy consumption (1.80 kWh/kg), the water activity of 0.57, shrinkage of 7.27, rehydration ratio of 2.40, and the maximum color retention. Thus, the IR-HA drying mode is superior to both HA and IR drying modes for shrimps drying.

Psilocybin: Characterization of the Metastable Zone Width (MSZW), Control of Anhydrous Polymorphs, and Particle Size Distribution (PSD).

Psilocybin, a serotonergic agonist, was granted a “breakthrough therapy” status by the Food and Drug Administration for clinical trials involving major depressive disorder and treatment-resistant depression. The direct phosphorylation of psilocin to psilocybin that uses a fast crystallization associated with a kinetically controlled process resulted in a smaller particle size distribution. Herein, the measurement of the metastable zone width (MSZW) and nucleation induction enabled a thermodynamically controlled crystallization process, which leads to the formation of a crystal structure with stronger interactions, controlled particle size distribution (PSD), and improved impurity profile. Employing a high-resolution inline microscopy viewer allowed the real-time monitoring of the crystallization process and the measurement of the particle size. We also present a comprehensive study of the formation of polymorph B (trihydrate), polymorph A (anhydrate), and polymorph H (anhydrate) using water recrystallization, which indicates that the formation of polymorph B (trihydrate) is independent of the crystallization method. However, polymorphs A and H are dependent on the mode of drying: drying at room temperature under vacuum gives rise to mainly polymorph A, and when heated even at relatively low temperatures, a mixture of polymorphs A and H beings to form.

Конвективная сушка пиломатериалов на основе управляемого влагообмена

Wood drying (in particular lumber drying), which almost entirely determines the quality of the wooden products, is one of the most complicated and energy-consuming processes in wood processing. Convective drying of lumber, in all its varieties, remains the most common by far. Computer modeling of wood drying processes is usually based on solving systems of differential heat and mass transfer equations. The methods for solving such systems, both analytical and numerical, are well researched and developed. However, the most important methodological issue is the correct formulation of the boundary conditions that determine the process of interrelated heat and mass transfer at the interface (wood – moist air). The convective drying has traditionally used the boundary conditions of type III by Academician A.V. Lykov, which are characterized by a sufficiently close correspondence between the mass flows moving from the wood depth and at the interface. This correspondence is described by the value of the so-called Bio mass transfer criterion. A computational experiment was carried out to verify these assumptions. It enabled to determine the possible controllability of the moisture removal during low-temperature convective drying of conventional lumber using modes of three-step and stepless structure. Besides this, the influence of the moisture removal on the dynamics of the internal stresses in wood was also studied. The results have shown that the stepless drying modes, on the one hand, offer a significant improvement in drying quality with practically no loss of drying capacity, and on the other hand, have better controllability. The results of the previously conducted and mentioned studies made it possible to propose general principles and then to patent a system for automatic control of moisture transfer during wood drying, which is fundamentally different from the previously known wood drying control systems. The system controls the drying process by adjusting the ratio of external to internal moisture transfer, rather than the value of the media parameters in the chamber. The moisture transfer control system for convective drying of lumber is of limited control: it cannot fully stabilize the values of the Bio mass transfer criterion. However, its use maintains a certain balance between internal and external moisture transfer, ensures the required drying quality and almost completely eliminates the occurrence of defects. For citation: Gorokhovsky A.G., Shishkina E.E., Agafonov A.S. Lumber Convective Drying Based on Controlled Moisture Transfer. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 166–172. DOI: 10.37482/0536-1036-2022-1-166-172

Analytical modeling and performance analysis of a solar cooker cum dryer unit

ABSTRACT In this work, analytical modeling and theoretical analysis of a recently developed unique design of a solar cooker cum dryer (SCCD) have been conducted to predict its thermal characteristics under a given set of input parameters. The energy balance equations of the main components of the cooking compartment are iteratively solved to determine the unknown temperatures of the SCCD unit when it operates as a pure cooker and when the same acts as an air heater for the food drying compartment. The influence of design parameters such as air velocity, glazing thickness, spacing between glazing, back reflector, and surface coatings of the absorber plate has been studied and quantified. The analytical model has been tested by simulating and validating the modeling results with the experimental data for different days of the year Moreover, further experiments are conducted on the SCCD in drying mode to quantify its thermal performance in natural versus forced convection of the airflow through the SCCD and to demonstrate its effectiveness in comparison to open sun food drying. The obtained results show that the SCCD unit attain cooking and drying temperatures in the suitable range of 80–135℃ and 50–70℃, respectively. The experimental results of the SCCD unit as a food dryer revealed that the Page model with higher adequacy is found to be the best fit for all three modes of food drying in the SCCD unit. It is found that in comparison to drying of tomatoes in the open sun which took ⁓13 hrs, forced convection of airflow in the SCCD unit resulted in the least time of ⁓7.5 hrs to achieve the desired level of moisture content. The energy and exergy efficiency of the SCCD in cooking mode was estimated to be in the range 2.1–15.5% and 1.1–5.6%, while it was 7.5–16.5% and 26.6–50.7% in drying mode, respectively.

Analysis of the temperature-frequency effect on dielectric losses in a grain medium

The aim of the study is to determine the influence of the thermal effect on dielectric losses in grain mass subject to bruising during drying and storage on the example of wheat across a wide external electric field frequency range. The study of the electrophysical characteristics of a dispersed medium comprising mechanically activated wheat grains takes into account the effect of the degree of breakage on the dielectric parameters of the studied medium. The studies were carried out on experimental samples having different degrees of mechanical activation of particles, which ranged in size from from 50 to 1000 μm. Variations in the dielectric loss tangent were studied using the dielectric method across a wide temperature-frequency range. Studies of variations in dielectric properties were carried out for wheat sam-ples subjected to grinding according to the mechanical activation method at temperatures varying from 20°C to 255°C with a constant heating rate of 0.7 deg / min. During the course of the experiment, the frequency of the external electric field was varied from 25 Hz to 1∙106 Hz. Dielectric constant and dielectric loss tangent calculations were carried out using data on electrical capacity and conductivity obtained using an E7-20 immittance meter and a measuring cell in the form of a flat capacitor. An analysis of variations in these dielectric characteristics was also performed. The obtained stable correlation of the dielectric loss tangent with the frequency of external electric impact and the degree of heating of the samples was most pronounced for finely dispersed samples (particle size 50 μm). Variations in dielectric characteristics are most significant when the frequency decreases to 100 Hz and below. The study of variations in the main dielectric parameters can be used to prevent self-heating and ignition of the grain mass during storage, as well as for selecting the most efficient energy-saving drying mode.

Comparative evaluation on drying of pomegranate arils for production of Anardana

Wild pomegranate is an important wild fruit of family Punicaceae which has got great economic importance. Pretreated arils (steam blanched for 30 sec followed by sulphuring @ 0.3% for 60 min) were dried by different intermittent drying modes to minimise energy utilization and maximise quality retention of dried arils within lower cost. Various drying modes used were mechanical cabinet drying (60±2°C), sun drying (18–31°C), solar tunnel (21–39°C) drying, combination of solar tunnel + mechanical cabinet drier, combination of open sun + solar tunnel drier and combination of open sun+ solar tunnel + mechanical cabinet drier. The quality of dried arils (anardana) obtained were compared on the basis of various physical chemical and sensory characteristics besides energy utilization in each method with economic analysis. Arils dried in mechanical cabinet drier possessed highest values of desirable physico-chemical characteristics viz., colour, TSS (45.20°B), titratable acidity (11.40%), ascorbic acid (11.70 mg/100g), total sugars (25.45%), anthocyanins (33.76 mg/100g), phenols (126.05 mg/100g), crude fibers (35.91%), oil (8.89%) and antioxidant activity (65.22%). It took minimum time (26 h) to dry a given tray load, had minimum non enzymatic browning (0.06 OD), furfural (11.89 ppb) and hydroxy methyl furfural (0.90 ppm), beside highest energy consumption for drying. Mechanical cabinet dried arils were rated best among all drying modes on the basis of highest sensory scores. However, quality of solar dried anardana was found to be at par with the mechanically dried anardana with low cost of production (Rs 251 per kg as against Rs 326 per kg).

Development and testing of novel photovoltaic-thermal collector-based solar dryer for green tea drying application

A sustainable solar based PVT tea drying system has been developed to minimize the dependency on the non-renewable commercial tea drying system. In this work, the effect of operating conditions on the performance of a photovoltaic-thermal (PVT) collector-based solar dryer is investigated under sunny and cloudy weather conditions for three different cases- Case-I (natural convection), Case-II (forced convection with an air velocity of 0.096 m/s), and Case-III (forced convection with an air velocity of 0.014 m/s). Firstly, energy performance of the PVT system has been evaluated for all the three cases under sunny and cloudy days, which show that the energy performance has been enhanced to a maximum value of 58.71% and 53.95% for sunny days and cloudy days, respectively, and these are obtained in case of case-III. Then the drying of green tea under mixed-mode drying (MMD) and indirect mode drying (IMD) are presented under sunny days for each of the three cases and compared with open sun drying (OSD) and shade drying (SD). The moisture content has been reduced from 2.95 (d.b.) to 0.14 (d.b.) in all the cases of drying modes. Further, the drying kinetics of green tea leaves is compared using existing models, and a new drying model is proposed, which is found to predict the moisture ratio better. The maximum PVT dryer efficiency, moisture effective diffusivity, and specific moisture extraction rate (SMER) are 26.37%, 4.97 × 10−9 m2/s, and 0.6125 kg/kWh, respectively, for MMD process.

DEVELOPMENT OF RESOURCE-SAVING TECHNOLOGY OF POROUS-HOLLOW CERAMIC STONES

A resource-saving technology of porous ceramic materials using low-quality non-sintering sandy loam as a basic raw material has been developed. Based on the analysis of the plastic properties of two- and three-component ceramic masses, including sandy loam, expanded clay and fuel slag in various ratios, it was found that the required level of their plasticity provides the content of the main raw material in the following range (wt%): fuel slag – 15 – 20; sandy loam – 50 – 65; expanded clay – 20 – 30. By the method of planning the experiment, the rational composition of the three-component ceramic mass was substantiated. This which contains: 62.5 wt. % sandy loam, 20 wt. % medium-sintering plastic clay as a plasticizer and 17.5 wt. % fuel slag of TPP as a porous agent. For the developed mass, the main technological properties were investigated, which made it possible to recommend the drying mode of the raw material – 60 hours, the optimal firing temperature – 950 °С. Such conditions ensure that samples are obtained without drying cracks and signs of deformation. Оn the results of dilatometric analysis of mass the rational mode of firing high-hollow semifinished products was designed. The firing mode provides for a 44-hour firing and a decrease in the heating rates in the areas of dehydration of clay minerals, direct quartz transition and intensive sintering of the mass, as well as a decrease in the cooling rate in the area of the reverse quartz transition. The proposed firing mode provides the degree of sintering and their properties necessary for ceramic materials. Based on the developed mass under the recommended drying and firing modes, porous ceramic materials with an apparent density of 1.48 g/cm3, a compressive strength of 18.2 MPa and frost resistance of 30 cycles were obtained. The developed materials belong to the group of conditionally effective, and if 50% of the voids are organized, they can be classified as effective.

Evaluation of Hop Drying Efficiency Based on Moisture Content Measurement with Different Variable-temperature Drying Modes

In order to solve the problems of long drying time and low drying sufficiency, the drying experiment was examined to verify the drying efficiency at different variable-temperature modes using the hop variety ‘Tuopu No.1’ obtained from Gansu Province A modified oven was taken as the baking media with a single-layer curing barn. The moisture content of the hop cones and the RH values of the hop layers at different drying temperatures were measured. Two optimal variable-temperature drying modes were selected, that was, in the drying process of hops, the temperature was set from 30 to 50 ℃(30~50 ℃) and from 30 to 60 ℃ and then down to 40 ℃(30~60~40 ℃). Baking with these two drying modes, the moisture content of hops could be reduced by 54.48% and 49.82% within 7 h, respectively. The drying efficiency was furtherly verified in the hop bakery of the workshop and the drying curves were analyzed. The linear models could give a good fit to the drying curves of the drying mode of 30~50 ℃(R2>0.96), while Weibull distribution models(β<1) fitted well to the drying mode of 30~60~40 ℃. It was proved that the two drying models belong to constant rate drying and falling rate drying, respectively. It was further verified that the drying efficiency was higher under the drying mode of 30~50 ℃. Hops drying at 30~60~40 ℃ had higher essential oil content, which was about 43% higher than that at 30~50 ℃. The above results indicated that the hops should be dried with a low temperature(30 ℃) in early stage and followed a high temperature(50 ℃) in late stage; In order to obtain more essential oil content in the final hops, the drying temperature could be reduced to some extent(40 ℃).

Influence of the drying regime on the quality indicators of dry mare’s milk

The data on the influence of the temperature regime of the spray drying process on the quality parameters of dry mare’s milk are given. The results of experimental studies on the selection of the optimal drying mode for maximum preservation of the quality indicators of the final product are presented. It was revealed that the optimum temperature during the drying process of mare’s milk is the temperature at the entrance to the dryer t = 180°C, at the exit t = 70-80°C. The study of qualitative indicators with this drying mode showed that the particle size (more than 68%) was 117-140 microns, the solubility index was 0.18 ml of insoluble sediment in 50 ml of reconstituted mare’s milk, the moisture in dry mare’s milk was 3.8% (at t = 180°C), which met all the requirements of the standard. In addition, it was found that the correct heat treatment of mare’s milk before drying also affects the quality indicators of the dry product. The most optimal temperature for milk pasteurization is a temperature of no more than 60°C.