Game animals are a source of biologically active substances that requires a strict resource and biodiversity control. The research objective was to analyze three years of supply, demand, export, and import for brown bear, deer, and musk deer by-products. The review featured Russian and foreign articles on game animals published in 2016–2020, as well as customs information on imports and exports for this raw material. The research methods included systematization, analysis, and description. The population of brown bears in the Russian Federation is constantly growing. In 2018, it increased by 4% compared to 2017. Bear derivatives are in high demand in China, Italy, France, etc. The total number of importers in 2019 exceeded 25. In 2017, deer products were the most popular game derivatives exported from Russia to 35 countries. The biggest importer is China. In 2018, the volume of exports of deer and musk deer derivatives maintained the same value, but the list of importers changed. In 2019, the export volume increased by 1.4 times, and the number of importing countries reached 50. Russia is the leading exporter and importer of raw materials and derivatives from brown bears, deer, and musk deer. The market for game derivatives is actively developing. An increase in the number of predatory game animals, e.g., the brown bear, may adversely affect the local ecosystems, which can be prevented by licensed hunting. The high content of biologically active substances makes it possible to use game raw materials for new functional products.
To ensure a balanced diet, bakers use plant-based raw materials with a high nutritional value which affect the properties of flour and dough. We aimed to study the effects of a complex additive based on plant components on wheat flour’s amylolytic activity and gas-forming ability, as well as on the dough’s rise and gas-retaining ability during fermentation. Our study objects included premium wheat flour, a water-flour suspension, and wheat dough with a complex additive (at concentrations of 10, 16, and 22% by weight of flour mixtures). The additive contained whole wheat flour, crushed sprouted spelt, powdered pumpkin seeds, oyster mushrooms, and gooseberries at a ratio of 56.3:25.0:17.2:0.9:0.6, respectively. An amylograph-E was used to study the viscosity of the water-flour suspension during heating, an ICHP-1-2 apparatus measured the falling number, and an F4 rheofermentometer assessed the flour’s gas-forming ability and the dough’s rise and gas-retaining ability. The complex additive improved the enzymatic activity of the flour, increased the dough rise by an average of 8.4 mm, and reduced the fermentation time needed to reach the maximum height by an average of 17.8%, compared to the control. The total volume of carbon dioxide, as well as the volumes of lost and retained carbon dioxide, increased by an average of 35.8, 99.7, and 26.9%, respectively, compared to the control. The optimal concentration of the complex additive introduced into premium wheat flour was 16%, at which the dough rose to its maximum height and had the longest porosity time. To obtain high-quality products with this concentration of the additive, the total time of dough fermentation and proofing should be reduced by 17.8% compared to the unfortified dough. The results can be used in the production of bakery products from premium wheat flour fortified with the complex additive based on plant components. During the process, it is important to determine the duration of dough maturation and reduce the total time of dough fermentation and proofing depending on the concentration of the additive. Further research is needed to study the effect of the complex additive on the structural and mechanical properties of dough during its development.
Pomegranate (Punica granatum L.) processing focuses on the extraction of polyphenols from peel. However, pomegranate peel is also rich in other biologically active water-soluble components, and their commercial extraction remains understudied. The research objective was to evaluate the degree of extraction of hydrophilic substances, such as simple sugars, organic acids, and polyphenols, from raw pomegranate peel and pulp under different experimental conditions in order to select the optimal extraction parameters. The study featured pomegranates of the Iridanaly variety (Geokchay, Azerbaijan). Raw peel and pulp were crushed to the state of a coarse gruel. Extraction occurred by maceration at a hydromodulus of 1:2 and a temperature of 40 or 60°C with pure water and aqueous ethanol solutions (10–14 % vol.). The process lasted 30, 60, or 90 min in one or two stages with separate extraction at each stage. The research involved standard physicochemical methods. In 31.0 ± 2.0 g/100 g of dry peel, the hydrophilic fraction accounted for 85.32%; in 35.7 ± 2.8 g/100 g of dry pulp, it was 59.36%. Only 54.6% solids were extracted from raw peel after 30 min of extraction with pure water at a hydromodulus of 1:2 and 60°C. Pomegranate peel contained hydrophilic colloids, which caused water absorption and reduced the yield. The optimal extraction included an aqueous solution of ethanol with an ethanol concentration of 10–14 % vol. and two thirty-minute stages. The coagulating effect of ethyl alcohol on water-soluble pectin made it possible to increase the degree of extraction of water-soluble substances to 83.93 and 91.4% of their initial content in raw peel and raw pulp, respectively. Such extraction yielded 4 kg of mixed extract from 1 kg of raw pulp. The extract was boiled under vacuum and yielded 260 g of concentrate with 60 wt.% solids, including 46.70 g/100 g simple sugars, 4.73 g/100 g organic acids, 3.70 g/100 g polyphenols, and 10.10 mg/100 g vitamin C. The extraction of raw pomegranate peel and pulp with aqueous ethanol (10–14 % vol.) provided the maximal degree of extraction of hydrophilic substances and facilitated the separation of the resulting extracts. However, strong alcohol solutions may increase the cost of distillation of alcohol from the extract. To eliminate this shortcoming, the extraction can be carried out with pure water and a pectolytic enzyme.
The food industry uses sonochemical treatment as part of emulsification, homogenization, and dispersion, as well as to modify viscosity and structure. Starch is one of the most common food ingredients, both as a raw material or a property-modifying additive. The research objective was to study the effect of sonochemical action on the structural and mechanical properties of wheat starch suspensions. The study involved suspension samples with 10% wheat starch. The suspension samples were treated with ultrasound using an ultrasonic device Volna-M model UZTA-1/22-OM or in an ultrasonic bath (22 kHz; 100, 150, 300, and 400 W). The treatment time was 15 and 30 min. The rheological, physical, and textural properties were recorded according to conventional methods before and after the treatment. The ultrasonic treatment caused mechanical damage to the starch, making it more accessible to moisture when heated. As a result, the structural, mechanical, and rheological properties of starch suspensions changed. All the studied suspensions had a non-Newtonian character. The ultrasonic treatment increased their consistency coefficient from 28.12 to 152.75 µPa·s. The gelatinization temperature of all experimental starch suspensions dropped from 63.4 to 61.0°C. The short high-power ultrasound treatment reduced the strength of gels to 1.25 N compared to that of native starch gel (4.28 N). In this research, the ultrasound treatment of wheat starch suspensions modified the structural, mechanical, and rheological profile of starch and proved able to replace some conventional starch modification procedures, i.e., chemical, physical, or enzymatic. The new approach can provide modified starches of a preset quality while reducing energy costs and processing time.
Public catering has become an important healthy food provider in Russia. As a rule, this sphere is represented by small businesses with no experience in innovation. Their prospects for innovative development depend on the form of ownership, size, and target audience. The present research objective was to develop recommendations on how to restructure a public catering enterprise as part of an innovative development strategy. The study featured public catering enterprises together with their innovative potential, activities, and factors that contribute to or hinder their development. The innovative restructuring scenarios were based on the synthesis method. The authors developed a goal-centered classification which includes commercial and socially oriented public catering enterprises with their own advantages and disadvantages. The list of disadvantages includes decentralization, overstaffing, and multi-format, which make it difficult to introduce innovations and strategizing. The restructuring process requires a new management system optimized by specialists competent in the field of innovation, as well as a new matrix of strategic resources. An audit of public catering enterprises makes it possible to assess their competitiveness and strategic prospects. The current lack of personnel with experience in innovations hinders the development of the industry. Universities and regional innovation infrastructure should provide public catering with specialists in innovation management.
Hydroponics is a method of soilless cultivation of plants. It shortens the vegetation period, reduces the risk of disease and insect infestation, and provides a year-round growing cycle. Hydroponics depends on efficient water management. It is associated with a complex design, operation, and maintenance. Neural networks can control complex technological processes in agriculture. The research objective was to use a neural network to increase the efficiency of a home hydroponics system. The study involved a nutrient bed hydroponics setup with ten Lactuca sativa plants. Sensors collected information about the temperature and humidity of air, illumination, and the temperature of the leaf surface. Data processing, neural network training, and microcontroller programming relied on Python 3, PyTorch, and MicroPython. The four-layer perceptron, which is a popular control mechanism, turned out to be the most effective neural network architecture. Fewer layers resulted in a high error rate (≥ 5%). When the number of layers was > 4, the error level remained at that of the four-layer experiment (0.2%). Further practical tests showed an increase in energy efficiency by 32.3%, compared to the classical control algorithm at close values of plant transpiration. Neural net technology could be integrated into energy-saving residential premises and smart home systems in order to increase the self-sufficiency of hydroponics installations.
Processed fruit and berry raw materials often become part of bakery formulations. They increase the nutritional value of the finished product and change the rheological properties of the dough. Processed sea buckthorn (Hippophaё rhamnoides L.) maintains natural biochemical properties, which makes it a valuable food ingredient. The research objective was to conduct a comprehensive study of the technological properties of dough made of rye and wheat flour with sea buckthorn meal and dry sea buckthorn extract. The research involved sea buckthorn extract and meal mixed with wheat and rye flour, as well as dough and bread from the experimental flour mixes. The experimental part included standard methods used in the bakery industry. The sea buckthorn meal and extract contained protein (10.3 and 4.3%), crude fiber (8.7 and 0.3%), pectin (5.27 and 0.11%), and ascorbic acid (21.63 and 53.68 mg/100 g). They were highly acidic: 4.9 and 3.0%, respectively. As a result, protein substances and dietary fibers took a longer time to swell. The high acidity also inhibited α-amylase, which improved the rheological properties but increased the dough development time and stability. The sea buckthorn products had a positive effect on the starch crystallization processes and reduced the storage-related starch degradation. The sensory evaluation of the bread described its shape as regular, with fluffy crumb and pleasant sea buckthorn flavor. Thus, sea buckthorn meal and extract proved excellent technological acidifiers and regulators of amylolytic activity. The additives made it possible to reduce the amount of liquid rye sourdough from 30 to 15% and the fermentation time because the dough acidity reached 7.5–8.0 degrees.
Poor packaging often affects the quality and safety indicators of wine during storage. The need to preserve and prolong wine stability during long-term storage requires a comprehensive study of processes that occur in wines packaged and capped in various ways. This research featured 56 samples of white and red dry wines, which were bottled in four types of packages and stopper for 18 months. The effect of synthetic and natural stopper methods involved a model system that simulated the main composition of wine in line with the EAEU standards. The contents of free SO2 and dissolved oxygen, as well as the microbiology of natural corks, were studied using standard methods. The analysis of volatile substances relied on gas chromatography, mass spectrometry, and solid phase micro-extraction. The study recorded critical changes in the quality of wine products, characterized by increased oxidation markers and low free sulfur dioxide, which fell below 10 mg/dm3. In polyethylene terephthalate bottles, these changes occurred after 12 months of storage, while it took them 18 months to develop in multilayer bags and combined packaging materials. The components of natural and artificial plugs of microbial and chemical origin entered the model systems after 10 days of contact. The microbiological contamination was twice as high as the permissible level. The migration of microbial and chemical substances into the wine samples spoiled their quality and safety. The effect of packaging on the oxidative processes in white and red dry wines during storage resulted in different concentrations of dissolved oxygen and sulfur dioxide. The results can help wine producers to choose the most appropriate packaging and stopper means depending on the wine sort and its subsequent storage conditions. Alternative types of packaging proved to have a limited shelf life.
Plant-based soft drinks are a relatively new product category. Germinated, or sprouted, buckwheat (Fagopyrum esculentum Moench.) can be used as a raw material in functional beverages. It has a good potential for expanding the range of this category. The research objective was to study the effect of formulation on the production technology and nutritional value of non-alcoholic beverages from germinated buckwheat. The study featured water-grain and water-fruit-grain mixes, as well as model samples of buckwheat drinks fortified with various fruit components, e.g., sea buckthorn, black currant, apple, etc. Standard research methods were supported by high performance liquid chromatography and atomic emission spectrometry. Buckwheat was soaked in water at 20 ± 2°C for 46 h. This germination method resulted in a high level of microbial contamination. To ensure food safety, the water-grain suspension was brought up to 65°C for 3 min. The fruit components increased the viscosity of the dispersion medium, as well as the settling time of solid particles. The mix had to be homogenized in order to reduce the particle size and destroy the colloidal system after heating (98 ± 2°C, 1 min). The final product had a harmonious taste and contained sugars (6.72–8.04 g/100 cm3), organic acids (338.91–446.93 mg/100 cm3), minerals (0.07–0.08%), and amino acids (leucine, lysine, cystine, and tyrosine). Buckwheat homogenization preserved the beneficial substances in the raw material. The samples fortified with sea buckthorn or blackcurrant puree had the best sensory profile and nutritional value.
The range of high-quality alcoholic beverages could be expanded by unconventional raw materials, e.g., bakery waste. Any new technology requires optimization of operating parameters at each production stage. The sensory properties of an alcoholic drink depend on the distillation mode. However, food science knows no objective methods for optimizing distillation parameters based on the biochemical composition of the raw material. The research objective was to develop a new methodology for optimizing the distillation procedure for alcoholic drinks based on unconventional raw materials. The research featured distillates obtained from industrial samples of bakery waste. The variable factors included the distillation rate, which ranged from 5 to 17 cm3/min, and the wort acidification degree, which was pH 6.0–2.0. The composition and mass concentration of the main volatile components were determined by gas chromatography using a Thermo Trace GC Ultra device (Thermo, USA) with a flame ionization detector. The sensory evaluation was performed by a panel of qualified experts. The single-factor experiment showed that the distillation rate and the wort acidification degree affected the concentration of each volatile component in the distillate. Using the method of pairwise correlation coefficients, the authors identified the most significant parameters: mass concentration of 1-propanol, phenylethyl alcohol, ethyl lactate, total enanthic esters, total enanthic esters vs. total esters, concentration of ethyl lactate vs. total enanthic esters, isobutanol concentration vs.1-propanol concentration. The linear pair correlation coefficients were calculated for these selected indicators, and the effect of each parameter on the sensory profile was represented as a regression model. The optimal operating parameters were determined by extremization of a two-variable function: pH 4.4 ± 0.2, speed 9.5 ± 1.0 cm3/min. The new methodology provided for the following sequence of operations: determining the significance of the variable factor; selecting the evaluation parameters based on a single-factor experiment; determining the interaction; developing a regression model. This method can be used to calculate the optimal technological distillation parameters for other raw materials.
Wines with a clear geographical origin are more attractive for customers. The geographical origin of wine is stated on its label, but no official standards guarantee its reliability. The present research objective was to analyze the existing methodological approaches to wine authentication. The study featured domestic and foreign publications indexed in Dimensions and Elibrary in 2017–2022 with such keywords as wine authentication, geographical origin of wine, and chemometrics. The research revealed no single methodological solution to wine authentication because food science knows a wide range of parameters, methods, analytical equipment, and data processing models. Chemometric methods are reliable because they are able to process large arrays of analytical research results structured in a data bank using the so-called fingerprint principle. They involve 2–65 markers that are individual for each geographical region, country, zone, or terroir. Another promising method is the quantitative and qualitative nuclear magnetic resonance spectroscopy (qNMR) of protons 1H and deuterium 2H(D) nuclei, as well as other elements (13C, 17O, 31P, 14N). The review resulted in an integrated approach based on a combination of isotopic testing with cation-anionic profiling. The analytical support involved the methods of atomic absorption and atomic emission spectroscopy, spectrometry with inductively coupled plasma, isotope ratio mass-spectrometry, and quantitative and qualitative nuclear magnetic resonance spectroscopy. This combined approach could provide background for an all-Russian state standard with a single algorithm for wine authentication tests. The new approach will be used to develop enochemical profiles of wines from a particular region, as well as to choose the most effective chemometric models for geographical authentication.
Ice cream is a popular cold dessert. Its air phase consists of tiny bubbles with an average diameter of 15–60 µm. New ice cream formulations depend on the way the composition and production factors affect the air phase. As a result, ice cream producers need new time-saving and reliable methods to determine dispersion. The research objective was to create a computer program for marking the position of centers and diameter of air bubbles on microscopic images of a bounding circle type. The review part included 20 years of Russian and English publications on microscopic research methods in ice cream production indexed in Web of Science and Russian Research Citation Index. Microscopic images of ice cream air phase were obtained using an Olympus CX41RF microscope with a magnification of ×100. The automatic markup program employed the Python programming language, the Keras machine learning library, and the TensorFlow framework. The models were trained using the NVIDIA GTX video accelerator. The review showed that the dispersion of ice cream air phase depends on its composition and the freezing parameters whereas bubble formation is usually described in line with the existing foaming theories. A training data set was obtained by manual labeling of microscopic images. The optimal number channels in the convolutional layers of a neural network with LeNet-type architecture was determined, which made it possible to classify images as spheres or non-spheres with an accuracy of ≥ 0.995. The sliding window method helped to determine the limits of the neural network triggering for the sliding window method were determined, which reached 7.5% of the diameter with lateral displacement and 12.5% with scaling. The developed algorithm automatically marked bubbles on microscopic images. The error in determining the average diameter was below 1.8%. The new method for automated calculation of the number and diameter of air bubbles in ice cream proved to be user-friendly. It can be found in public domain, and researchers are free to adapt it to solve various computer vision issues.
Marketing communications create a positive brand image and attract potential consumers while providing close interaction with the target audience and increasing competitiveness. By combining approaches and tools, food companies increase the effectiveness of marketing communications and avoid communication barriers, thus achieving their profit targets in sales and advertising. The research featured consumer preferences in the field of dairy products. The research involved such methods as observation and survey; the obtained data underwent statistical, economic, and graphic processing. The survey involved 388 residents of the city of Kemerovo and the case of the local dairy producer Naturalnoe Moloko LLC, Kemerovo. The main barriers of marketing communications usually include barriers of perception, presentation, and interaction. The case study revealed barriers connected with installation, interaction, motivation, and comfort. The barriers could be minimized using digital marketing communications. The target audience saw the information availability about dairy companies and their products as important. This information can be provided by websites, social network accounts, and chat bots. In modern economic environment, a company is only as successful as its marketing communications. The survey data made it possible to formulate recommendations on how dairy companies can overcome communication barriers, based on the requirements of their target audience and their preferences regarding the place of purchase, choice, and communication channels.
Meat is an inherent part of human diet. Its quality develops at different stages of production, storage, and processing. In this respect, the stage of aging is especially important. This technology makes it possible to regulate biochemical processes in meat raw materials. Long-term dry aging is a promising method that presupposes conditions that limit the growth of microorganisms. The transformations in the protein component are an important but understudied aspect of meat quality formation during dry aging. The research featured Hereford beef carcasses of Siberian breeding. The samples were isolated from the inner part of bone spinal-lumbar cuts after 21, 35, and 42 days of dry aging under the following conditions: 0–1°C, 74–75% relative humidity, 0.5 m/s air velocity. The samples were subjected to dry aging after 24 h at 4°C. The fractional composition of proteins was controlled by vertical electrophoresis in a Mini-Protean Tetra System chamber. The amino acid composition was defined by high-performance liquid chromatography in a Shimadzu LC-20 Prominence liquid chromatograph with a Shimadzu SPD20MA diode-matrix detector and a Kromasil C-18 separation column. The protein digestibility was measured by sequential exposure to pepsin-trypsin proteinase system under simulated gastric digestion. Long-time dry aging triggered proteolysis under the action of endogenous enzymes. The electropherogram analysis showed that the proteolytic changes in high-molecular myofibrillar proteins of high-quality beef became more pronounced after a longer maturation period. The distribution of protein fractions by dry aging stages indicated a different rate of degradation of contractile, regulatory, and cytoskeletal proteins. As a result, the structural integrity of muscle fibers degraded, the meat grew tender, and the proteins became more available to digestive enzymes. The amino acid and protein digestibility analyses in vitro demonstrated an increase in the nutritional value of beef and the availability of proteins to the action of proteinases after 42 days of dry aging. Long-term dry aging of high-quality beef increased the digestibility of muscle proteins as a result of proteolysis that accompanied the accumulation of low-molecular fractions. According to the amino acid analysis, the optimal result was most pronounced on day 42 as proven by the moderate oxidative changes in proteins.
Proteomic technologies make it possible to evaluate the composition of meat raw materials at different stages of processing. Proteomic studies of lamb muscle tissue help to expand scientific knowledge about the effect of essential organic microelements on the interaction of lamb muscle tissue proteins. The research objective was to identify and quantify lamb muscle tissue proteins from young sheep grown on feed additives fortified with microelements. The research featured meat from young sheep of the Edilbaev breed aged 7 months that consumed additives Yoddar-Zn and DAFS-25 as part of their diet. The experiment lasted 105 days. The microelement composition of lamb muscle tissue underwent atomic absorption spectrometry. The proteomic profile was identified using O'Farrell’s two-dimensional gel electrophoresis (2-DE) with isoelectrofocusing in ampholine (IEF-PAGE). Aluminum, iodine, silicon, selenium, and zinc were identified in lamb samples from young sheep that received feed additives Yoddar-Zn and DAFS-25 for 105 days. Major protein fractions included eight with a molecular weight of 12–15 kDa, 42 with 16–30 kDa, and 45 with 35–110 kDa (pI 5.0–8.0). The samples contained glutathione-S-transferase, which is responsible for biotransformation of toxic compounds, maintenance of intracellular homeostasis, and stress resistance. All the experimental samples had triose phosphate isomerase (glycolysis enzyme). The tests also revealed superoxide dismutase, which catalyzes the superoxide radical into peroxides and oxygen, thus protecting body cells from free oxygen radicals. The research provided relevant data on the effect of innovative feed additives on the molecular mechanisms that occur in mutton muscle tissue and affect the proteomic profile of meat proteins and electrophoretic activity. The feed additives with organic microelements proved efficient. The results can be used to model and adjust autolysis in order to obtain meat with the necessary technological properties.
Hydrocolloids make it possible to produce low-calorie analogues of traditional foods that maintain the original structural properties. Electrophysical methods control viscosity and stabilize food systems. However, the stabilizing effect of ultrasonic treatment on gel remains understudied. The research featured the effect of ultrasonic treatment on hydrocolloids (polysaccharides) used in meat or fish jelly, marmalades, marshmallows, puddings, ice cream, etc. The study involved samples of colloidal systems based on iota-carrageenan or guar gum and purified water (1:100). The samples underwent ultrasonic treatment at various time and pH ranges. The viscosity, active acidity, temperature, and transparency (transmission coefficient, T, %) of the obtained colloidal systems were determined using standard methods, while the sensory profile was defined by the descriptor-profile method. Hydrocolloids were subjected to ultrasound at pH 3.9, 7.0, and 9.0. The colloidal viscosity of the iota-carrageenan sample was 47.6 mPa·s at neutral pH, 45.7 mPa·s at acidic pH, and 22.3 mPa·s at alkaline pH. The viscosity of the hydrocolloid system with guar gum depended on the pH of the medium: it decreased during processing from 119.0 to 64.8 mPa·s in the neutral medium but remained the same (3.5 ± 0.2 mPa·s) in the acid medium and reached 6.52 mPa·s in the alkaline medium. The maximum temperature of the colloidal system was 46.5°C in a neutral medium. The system with iota-carrageenan showed the best result at medium acidity in the range of 3.9–6.0 units and produced a fluid gel-like structure. Sonicated iota-carrageenan could be recommended as a gelling agent. Guar gum viscosity, on the contrary, lost its viscosity and failed to produce the desired structure.
Antibiotics have traditionally been used to prevent and treat common diseases in farm animals. However, residual antibiotics in dairy products and meat remain a serious public health problem, which is associated with antibiotic resistance. The research objective was to assess the impact of antibiotic contamination on the quality and safety of dairy products, the microbiological composition of milk, and antibiotic-resistant bacteria. The study featured six years of Russian and foreign scientific articles registered in PubMed (National Center for Biotechnology Information, USA), Scopus and ScienceDirect (Elsevier, the Netherlands), Web of Science (Clarivate, USA), and eLibrary.ru. The analysis involved 63 foreign and domestic sources. Residual antibiotics in milk inhibits the vital activity of lactic acid bacteria, which, in its turn, disrupts the technological process of yogurts, cheeses, etc. After such processing as normalization, pasteurization, and homogenization, antibiotics accumulate in fermented dairy products and bind with milk proteins and fats. Antibiotics, in their initial amount, enter yoghurts from dairy raw materials. In cheese production, antibiotics usually pass into the whey, but aminoglycosides, quinolones, and tetracyclines remain in the finished product because they bind with the protein fraction. The problem of biological safety of dairy products is associated with antibiotic resistance developed by human intestinal microbiota. This problem remains understudied, and the number of scientific papers on the matter is limited.
Food products change their quality during storage not only under the external impact, but also because they are complex in composition. As a result, food scientists look for new methods to control these internal changes. The research objective was to describe the changes in the physicochemical properties of apple puree during storage at elevated temperatures (40–60°C) and link them with the changes in the sensory profile. The study featured homogenized apple puree packaged in composite material and heated up to 40, 50, and 60°C. The colorimetric studies were conducted at 45°/0°, light source D65. The proton relaxation time and the water diffusion coefficient (impulse gradient method) were studied at a frequency of 20 MHz. The analysis of molecular dynamics involved the method of electron paramagnetic resonance of spin probes. The samples were cooled down to –70°C to measure the content of non-crystallizing water by the method of differential scanning calorimetry. The color change rate was constant and followed the zero-order kinetic reaction equation with an activation energy of 92 kJ/mol. The changes in color, proton relaxation, and sensory properties correlated when the samples were stored at 50 and 60°C. The analysis of the magnetic relaxation time, the diffusion coefficient of water, and the content of non-crystallizing water indicated that the main changes in the physical structure of the puree during heat treatment occurred as a result of the aggregation of apple cell fragments. These findings were confirmed by the optical microscopy. A prolonged exposure to 40–60°C affected the color, the relaxation of water protons, and the size of aggregates of apple cell fragments. It also affected the amount of water that did not crystallize at –70°C. The correspondence between the values of the activation energies was determined by the methods of colorimetry and proton relaxation. Therefore, the coloration and the water changes depended on the same processes. These physical and chemical properties can be used for quantitative assessment of apple puree under thermal treatment.
Low-pressure vacuum evaporation is an effective way to obtain dry concentrates. However, some factors may affect its efficiency and speed. This article introduces the effect of technological factors on the evaporation process in a rotary evaporator. The research objective was to select the optimal mode to obtain concentrates and extracts from plant materials. The experimental studies involved standard research methods and a BUCHI Rotavapor laboratory rotary evaporator (BUCHI, Switzerland). The research featured a water-alcohol extract of wild blueberries and an enzymatic hydrolysate of grain sorghum (durra), obtained by biotechnological treatment with amylolytic enzyme preparations. The optimal evaporation mode included the following values: the volume of the evaporation flask was 1 L; the wall thickness of the flask was 1.8 mm; the angle of inclination was 25°; the rotation speed was 280 rpm; the temperature heating bath was 50–60°C; the steam temperature in the evaporator was 30–40°C. For condensation, the temperature of the refrigerant in the condenser was 10–20°C. The experiment yielded a concentrate of blue-violet blueberries with 70–72% solids. The content of polyphenolic compounds was 1.86 times as high as in the original water-alcohol extract while that of anthocyanins was 1.4 times as high. The enzymatic hydrolysate of grain sorghum yielded a condensed sugar syrup with 78–80% solids and 91–92% reducing sugars in terms of glucose equivalent. The research provided optimal modes of evaporation for extracts and enzymatic hydrolysates from plant raw materials in a rotary evaporator. The plant concentrates had a high content of solids and maintained the sensory properties of the raw material.
The dairy industry needs new and more energy-efficient technological procedure for milk pasteurization. This article introduces a comparative efficiency assessment of various milk pasteurization technologies and electrotechnological means. The study featured milk, which was heated from 20 to 75°C with a capacity of 1000 kg/h at an estimated power of 58.95 kW. The treatment involved a steam-to-milk pasteurizer with electric indirect or direct heating, an induction pasteurizer, and a thermosiphon pasteurizer with direct or indirect electric heating. The study relied on the methods of energy and exergy analyses. The system of steam-to-milk pasteurizer with electric indirect (elemental, induction) or direct (electrode) heating demonstrated the following indicators: exergy loss – 1.29 kW, power consumption – 71.29 kW, exergy efficiency – 0.99, energy efficiency – 0.827. The thermosiphon pasteurizer with direct or indirect electric heating demonstrated the following properties: exergy loss – 1.29 kW, power consumption – 60.92 kW, exergy efficiency – 0.99, energy efficiency – 0.9676. The induction pasteurizer had the least competitive parameters: exergy loss – 10.8 kW, power consumption – 70.43 kW, exergy efficiency – 0.867, energy efficiency – 0.837. The thermosiphon pasteurizer with direct or indirect electric heating was able to increase the energy efficiency of milk pasteurization, while the induction pasteurizer proved to be a promising R&D direction.
