Volume 51, Issue 3, 2021
Introduction. Negative trends in the service market make food companies create competitive products that meet the needs of consumers. The COVID-19 pandemic exacerbated the need to design new formulations that meet complex requirements and use IT options. The research objective was to create a new approach to the development of products for various types of food industry enterprises. Study objects and methods. The research featured a questionnaire, in which Kemerovo citizens were asked to establish and rank a list of consumer properties for food served at cafes, restaurants, and canteens, as well as to define the ratio of prescription components of model samples and the quality indicators of model samples. The study was based on standard survey methods, sensory and microbiological evaluation, and the Delphi 7software. Results and discussion. The research revealed nomenclature of consumer properties (15 names) of public catering products, which were classified into seven groups of indicators. The following indicators received the highest score (86–100 points): sensory indicators, quality indicators, safety and freshness, appearance, and price. Caloric value proved to be of a relatively low significance (≤ 42 points). The research resulted in a methodology for designing competitive products based on consumer preferences and new application software. Conclusion. Food companies should take into account the degree of significance of particular indicators to create popular and cost-friendly dishes. This research offers a new methodology for designing competitive products based on consumer preferences and the application of the developed program. The consistency and effectiveness of the proposed approach was confirmed by testing the developed dishes at cafes and school canteens.
Introduction. The concentration of biogenic amines is an important indicator of the safety of food products, especially winemaking. In grape wines, this concentration varies widely depending on the grape variety, its microbiological state, processing technology, the race of yeast and bacteria of malolactic fermentation, conditions of alcoholic and malolactic fermentation, etc. This research is aimed at determining the effect of the production technology of dry white and red wines on the concentration of biogenic amines. Study objects and methods. The mass concentration of biogenic amines was determined by the method of high-performance capillary electrophoresis using a Kapel 105R in laboratory-obtained samples of dry white wine from the Chardonnay grape variety and table dry red wine from the Cabernet-Sauvignon grape variety. Results and discussion. The dry white wine samples revealed high concentrations of tyramine (1.12 mg/dm³), phenylethydamine (0.58 mg/dm³), and histamine (0.57 mg/dm³), while the red wine samples demonstrated tyramine (0.62 mg/dm³), histamine (0.45 mg/dm³), putrescine (0.43 mg/dm³), and cadaverine (0.38 mg/dm³). The white wine samples had optimal pH values (3.2–3.6) with minimal formation of biogenic amines. The red wine samples, especially those obtained by heat treatment, had a lower concentration of biogenic amines, especially volatile biogenic amines, i.e. methylamine and phenylethylamine. The greatest formation of biogenic amines occurred during the acid reduction process: under the effect of enzymes of malolactic bacteria, biogenic amines formed as a result of decarboxylation of amino acids. Conclusion. The technology of production of table dry white and red wines affects the concentration of biogenic amines. To reduce the level of biogenic amines in the finished product, each stage of vinification has to be controlled, especially the stages of fermentation and acid reduction (temperature and pH). The race of yeast and lactic acid bacteria cannot include those that produce biogenic amines or introduce them in minimal quantities.
Improvement of Technological Indicators of Semi-Finished Products of Sugar Production from Bacterially Infected Sugar Beet
Introduction. Technological aids play a special role in sugar production technology, but their complex effectiveness requires a comprehensive and in-depth study. The research objective was to establish the patterns of change in the technological indicators of semi-finished products obtained from bacterially infected sugar beets with the combined use of an enzyme preparation, antimicrobial agent, and defoamer. Study objects and methods. The study involved such semi-finished products as juice (diffusion, pre-defecated, first and second saturation) and syrup, the quality of which was determined according to standard methods. The laboratory experiment was carried out on the basis of the second-order D-optimal Box-Behnken plan for three factors at three levels. Results and discussion. The research revealed positive dynamics of the following technological indicators: sucrose content, deposition rate, turbidity, chromaticity, and general purification effect. The sugar beet had the second degree of infection with mucous bacteriosis. Purified juice underwent lime-carbon dioxide purification and thickening under the combination of enzyme preparation Dextrasept 2, antimicrobial agent Betasept, and antifoam agent Voltes FSS 93. The greatest increase in sucrose at the level of 1.1% by DM weight was confirmed by a higher overall effect of purification of diffusion juice (2.2 %). The values of turbidity of the purified juice and syrup were below the threshold values. The low values resulted from the increase in the sedimentation rate of the pre-defective juice and the juice of the first saturation by an average of 4.1 and 3.2 times, respectively, due to the effective removal of high molecular weight compounds. The share of the enzyme preparation was 40–71%, antimicrobial agent – 19–49%, defoamer – 1.6–6.5%. The values of the multicriteria optimization parameter corresponded with technological indicators. The optimal combination (per 1000 tons of beets) included 6–8 kg of Dextrasept 2, 1.5–2.0 kg of Betasept, and 15–20 kg of Voltes FSS 93. As a result, the yield of white sugar increased by 0.25%. Conclusion. The regression dependencies can be recommended for predicting the main technological indicators of semi-finished products. The resulting data makes it possible to determine the effectiveness of the combined use of an enzyme preparation, antimicrobial agent, and defoamer in sugar production. Further research will identify the patterns of multifactorial interaction of these preparations.
Introduction. Bread and bakery products contain nutritional components that make an integral part of human diet. Starter cultures are a promising way to prepare bakery products. The research objective was to study the effect of non-traditional flours and their wheat mixes on the activity, sensory, and physicochemical properties of starter cultures. Study objects and methods. The research featured Lesaffre starter cultures (Saf-Levain LV1 and Saf-Levain LV4) with lentil flour and green buckwheat flour. It involved organoleptic, titrimetric, and photocolorimetric methods, as well as the “ball surfacing” method, to determine the fermentation activity of starter cultures and to assess the changes in their volume. The acid content of the flour was determined by titrating the aqueous solution of the sample. The amount of reducing sugars was determined by the photocolorimetric method based on the interaction of carbonyl groups of sugars in an alkaline medium with copper glycerate; the optical density of the resulting solution was performed using a photoelectrocolorimeter. The change in the volume of the starter cultures was determined by a non-standard method of using measuring cups in the process of thermostating. The research also included a sensory evaluation of the semi-finished products. Results and discussion. Green buckwheat flour had a positive effect on the activity of starter cultures based on Saf-Levain LV4 and LV1. The sensory properties of starter cultures with non-traditional flours differed from the control samples in aroma, taste, appearance, and inflation rate. The acidity of the samples varied depending on the flour, its quantity, and the starting culture. The greatest accumulation of acids occurred in the sample with 50% of green buckwheat flour and the samples with 25 and 50% of lentil flour. The most intense reduction in the amount of reducing sugars was observed in the samples with 25 and 50% of green buckwheat flour (from 1.9 to 3.9 times, depending on the sample). In the samples with lentil flour, it was 75 and 100% (from 2.7 to 7.5 times, depending on the sample). The difference in the samples with LV1 was greater than in the samples with LV4, which can be explained by the differences in their microbial composition. The inflation rate was higher in the test samples than in the control. Conclusion. The resulting starter cultures can be recommended for baking industry and further research. Starter cultures based on non-traditional flours will eventually reduce the fermentation time and produce bakery products with high consumer properties. The non-traditional flours can expand the range of bakery products and increase their nutritional value.
Introduction. Beverages based on fruit distillates belong to elite alcoholic drinks. As a result, there is a high risk of counterfeit. Controlled indicators do not allow identifying distillates by the type of raw material. The research objective was to develop scientifically based identification criteria for fruit distillates. Study objects and methods. The research featured ten fruits and their distillates. It involved three schemes of pre-distillation processing: pulp fermentation, juice fermentation, and pulp fermentation with subsequent maceration. The biochemical composition of raw materials was assessed by the HPLC analysis of mass concentration of sugars, titratable acids, pH, mono- and disaccharides, free organic acids and amino acids, as well as by the sugar-acid index. The concentration of higher alcohols in the distillates was determined using gas chromatography. Results and discussion. The research revealed significant differences in the biochemical composition of raw materials, which made it possible to divide it into groups depending on the methods of pre-distillation processing. The groups can be identified by the ratio of the concentrations of the main higher alcohols: 1-propanol to the sum of isobutanol and isoamylol. The revealed differences were caused by the peculiarities of the ratio of organic acids and amino acids. For the distillates of Cornelian cherry, black currant, cherry-plum, plum, cherry, and apricot, the ratio of 1-propanol to the sum of isobutanol and isoamylol was within the following ranges: 0.02–0.06, 0.08–0.10, 0.30–0.35, 0.47–0.51, 0.55–0.65, and 0.69–0.92, respectively. The method of preparing raw materials for distillation did not affect the values of the identification indicator. Conclusion. The ratio of 1-propanol to the sum of isobutanol and isoamylol could serve as an indicator for the identification of distillates of Cornelian cherries, black currant, cherry-plum, plum, cherry, and apricot. However, it proved useless for distillates of pears, raspberries, tangerines, and mulberries, since its values were within comparable limits. Therefore, the research requires a GC-MS analysis to determine the concentration and ratios of other specific volatile components in other raw materials.
Introduction. Today, dietary supplements are an integral part of human diet. Some of them are made of hydrolysates of animal origin. Biologically active additives of immunomodulatory action can prevent various diseases. The research objective was to develop a dietary supplement from the bursa of Fabricius obtained from broiler chickens and evaluate its effect on cell viability in culture. Study objects and methods. The study featured biologically active supplement obtained by enzymatic hydrolysis of the bursa of Fabricius, immature stem cells, and adult differentiated cells of human dermal fibroblasts, HeLa and MCF-7 cancer cells, and extract of the bursa of Fabricius. Results and discussion. The research resulted in a new technology of dietary supplement production from the bursa of Fabricius of broiler chickens. It included washing, cutting, homogenization, proteolytic enzyme fermentation, and ultrafiltration. When introduced into the culture of mesenchymal stem cells, the dietary supplement caused a slight decrease in the cell viability at concentrations of 25 and 50%, which indicated a possible cytotoxic effect of the extract on mesenchymal cells. The extract did not affect the viability of human fibroblast culture and caused no cytotoxic effect. In MCF-7 culture, the extract had a dose-dependent cytotoxic effect, which lowered the relative cell viability. Conclusion. The new dietary supplement based on the bursa of Fabricius of broiler chickens had a cytotoxic effect on stem cell cultures. However, it did not affect the cell viability and had no cytotoxic effect on human dermal fibroblasts. The effect depended on the cell culture. In the case of HeLa, the supplement stimulated proliferative activity, and in the case of MCF-7, it had a cytotoxic effect. Therefore, the new dietary supplement demonstrated some prospects as an active ingredient for various biologically active additives and immunomodulatory drugs.
Methods of Assessing Milk Proteins Coagulation as a Part of the Forecasting System of Technological Properties
Introduction. An integrated monitoring of raw milk’s contents, quality, and security is a key factor that guarantees the high-quality dairy production. As a result, new research methods of rennet clotting are a topical and urgent area of study. The research objective was to systemize and analyze the basic criteria and assessment methods of rennet-induced protein gels in milk systems. Study objects and methods. The authors reviewed the official Russian criteria and methods of raw milk assessment by its rennet coagulation properties. The research also featured the most widespread instrumental approaches used in best practices from around the world. Results and discussion. In Russian and foreign cheese production, milk is always tested for its physicochemical and microbiological indicators, with a mandatory check of its coagulation characteristics. Russian cheese-makers use different modifications of rennet and rennet-fermenting tests based on subjective sensory evaluation, while international scientific trends in this area aim at developing and improving instrumental methods by using a complex indicator MCP. This indicator characterizes the parameters of rennet coagulation with the help of such devices as Formagraph, Lattodinamografo, Optigraph, etc. Formagraph is a simple instrument for measuring rheological properties of milk clotting. It was popular in the late XX century. The resent years saw the development of other methods of instrumental control, including those based on optical measurements. For instance, Ortigraph is one such instrument that receives unified data on coagulation properties of raw milk by using near-infrared waves. Sensory and instrumental methods have their advantages and disadvantages. However, the most significant criteria for a quick test of cheeseability, yield, and quality are the speed of analysis and the comparability and reproducibility of results. Conclusion. To improve cheeseability testing, Russian cheese-makers need to use the international experience, which offers standardized evaluation criteria in combination with various instrumental approaches. However, the integration of foreign regulations and methods into Russian studies is not the only option. The improvement and development of national instrumental methods of evaluating milk protein coagulation is also crucial.
Introduction. Forest berry plants are popular on the food market and in pharmacy for their high nutritional and medicinal value. Plantations of forest berry plants can proliferate on unused lands, including depleted peatlands. Clonal micropropagation is the most effective method for obtaining large quantities of high quality planting material. Light-emitting diodes are highly effective for clonal micropropagation. The research objective was to study the effect of different spectral ranges on the process of root formation of forest berry plants in vitro. Study objects and methods. The research featured regenerant plants of half-highbush blueberry, arctic bramble, American cranberry, European cranberry, lingonberry, and Kamchatka bilberry of different cultivars. A set of experiments made it possible to study the effect of lighting type on the growth and development of the root system of forest berry plants in vitro using white fluorescent lamps, white spectrum LED lamps, and LED lamps with a combination of white, red, and blue spectra at the in vitro rooting stage of clonal micropropagation. Results and its discussion. The largest number (3.4–14.6 pcs.) and the maximum total length (10.0–156.9 cm) of roots were observed under LED lamps with a combination of white, red, and blue spectra. The effect was by 1.1–2.8 and 2.0–4.5 times higher than in the case of white-spectrum LED lamps, and by 2.3–7.0 and 3.3–14.9 times than in the case of fluorescent lamps. Variety and shape proved to have no significant effect on biometric indicators. Conclusion. LED lamps had a positive effect on the process of rhizogenesis of forest berry plants during clonal micropropagation. They appeared to be more effective than fluorescent lamps. The combination of white, blue, and red spectra increased the biometric parameters of plants at the stage of in vitro rooting.
Formation of Indicators for Assessing the Effectiveness of the Use of Human Capital in the Food Industry
Introduction. No standard methodological approach has yet been developed for an objective assessment of the value of the human resource from the position of its effect on the results of the related industry. Food industry is a strategically important branch of the National Economy. It has its specific requirements for labor resources, which can be used as indicators of their effective use in the production process. The on-going transformation of the food industry structure requires customization of such indicators. The present research objective was to form a group of indicators to assess the efficiency of the use of human capital in food industry. Study objects and methods. Food industry ensures domestic food security and provides the rational use of all resources in the production process. The research featured indicators of human capital assessment adopted in international financial reporting, as well as methods of statistical and mathematical data analysis. Results and discussion. The present article introduces a new methodological approach to determine the impact of human capital on the socio-economic efficiency of a food industry enterprise. The calculation of the integrated human capital index was based on statistical indicators of demand and the intellectual component in the industry, e.g. indices of employment, education, and industrial production. According to the proposed approach, the indicative function was performed by an integrated indicator of socio-economic development, which included indices reduced to a comparable form. The indices reflected the ecological, economic, and social efficiency of food production. The method was tested at a local cereal-producing company. An average increase in costs for the development of human capital by 1% increased the indicators of the socio-economic development from 4 to 5%. The objectivity of the assessment depended on the provision of a given level of human capital development and the choice of target criteria for the development of the food industry. Conclusion. The proposed method can facilitate labor management decisions in food industry. The list of indicators can be expanded in accordance with the objectives and installations of scientific research.
Properties of Polyphenols and Xylooligosaccharides Obtained Biotechnologically from Processed Millets
Introduction. Thousands of tons of millet grain are processed annually in the world. Husk is the main waste of millet processing and can produce biologically valuable components. The present research offers a new biotechnology for the production of biologically active substances (BAS), namely polyphenols and xylooligosaccharides (XOS), from millet husk. Study objects and methods. Millet husk was tested for the mass fraction of protein, moisture, starch, fiber, and reducing substances, as well as for antiradical activity, qualitative and quantitative composition of phenolic substances, fractional composition of carbohydrates, monosaccharide composition of polysaccharides, qualitative and quantitative compositions of XOS concentrates. Results and discussion. The obtained BAS concentrates contained 0.90% of protein and 91.50% of carbohydrates, including 68.50% of XOS with prebiotic properties and 6.30% of ash. The concentrate of polyphenols was represented to a greater extent by ferulic acid (33.47%) with antioxidant activity up to 74.0%. The process of enzymatic hydrolysis demonstrated a significant change in the fractional composition of the extracted oxycinnamic acids, which make up the polyphenolic compounds of millet husk. In the polyphenol concentrate, the yield of ferulic acid increased by 19%, and that of gallic acid – by 2.5%, whereas the yield of chlorogenic acid decreased by 13%. The XOS concentrate mainly consisted of XOS fragments with prebiotic properties – up to 78% in absolutely dry matter. The fractional composition of the XOS concentrate revealed the presence of di-, tri-, tetra-, and pentaxylo-oligosaccharides. Xylotriose and xylotetrose prevailed in the KOS concentrates: 15.83 and 16.23%, respectively. The waste of enzymatic husk processing proved to be a concentrate of valuable dietary fiber that can be used as an independent product in the technologies of balanced and dietary nutrition. Conclusion. Millet husk is an excellent source of polyphenolic compounds with antioxidant and prebiotic properties and can be used in functional food production.
Introduction. The choice and justification of options for attracting investments are relevant for the development of any organization. The research objective was to assess exchange-traded options for attracting investment by small and medium businesses in the food and processing industry. Study objects and methods. The research featured small and medium businesses in the food and processing industry and their exchange options for attracting external financing. The study was based on system, situational, structural-functional, and process approaches, as well as methods of comparative and factor analysis, grouping, and sociological research techniques. Results and discussion. The authors described, analyzed, and classified ways to attract external financing by small and medium businesses. Exchange-traded options proved to be associated with the circulation of securities that differ in liquidity, direct access to the owners of funds, and access to a potentially unlimited amount of investment capital. The authors analyzed the existing exchange infrastructure for the businesses under consideration and assessed their potential for issuing securities. Based on such indicators as Average EBIT Margin and Compound Annual Growth Rate (CAGR), small and medium food-related enterprises can issuer securities, especially exchange-traded bonds. Exchange-traded bonds demonstrated a number of serious disadvantages, compared to a traditional bank loan. However, issuers of securities receive guaranteed advantages, e.g. more flexible conditions for raising funds on the exchange, the right to state subsidies for the payment of coupon income, partial compensation for the costs of placing securities, the absence of collateral, a wide range of private investors, etc. Using some real cases, the authors evaluated the liquidity of exchange-traded bonds of small and medium businesses in the food and processing industry according to a number of indicators of profitability and liquidity of securities. Conclusion. Exchange options can be used to finance small and medium food-related businesses, based on the established ex-change infrastructure, government incentives, potential of the food sector, average EBIT profitability, and revenue growth.
Introduction. Buckwheat grain has long been used in food technology. However, its aboveground part remains understudied even though it is richer in biologically active substances than grain. The research objective was to evaluate the potential of buckwheat grass as a raw material for functional tea beverages. Study objects and methods. The research featured the lower and upper parts of the stem, leaves, and flowers of common buckwheat, as well as buckwheat tea beverages. The content of polyphenol compounds was determined by the Folin-Ciocalteu method, while the amount of rutin was measured by HPLC analysis. Sensory properties were analyzed by standard methods and quality score, and antioxidant activity – by DPPH radical scavenging method. Results and discussion. The sensory analyses proved that the best tea beverages were made from the upper part of the plant: the samples had a strong smell of meadow grass and honey. The taste of the samples was pleasant, sweetish, with a honey and light floral aftertaste. As the total score (maximum score – 20) increased, the tea samples were arranged in the following order: lower stem (14.3) > upper stem (16.8) > leaves, (18.5) > blend – mix of leaves, flowers, and upper stem (18.6) > flowers (19.3). Polyphenol compounds were found in all parts of the plant: flowers – 6.67%, leaves – 5.71%, blend – 5.45%, upper and lower stem – 1.92 and 1.32%, respectively. Only 30–40% of buckwheat grass polyphenol compounds were found in tea beverages. Most of them were in the samples prepared from leaves and flowers – 1.78 %. Rutin made up most of the polyphenol compounds found in the leaves (5.05%), but its content was lower in other parts of the plant: 3.43% in the blend, 3.03% in the flowers, 1.08 and 0.76% in the upper and lower stem. Except for the lower stem samples, the tea contained from 15 to 75% of the daily rutin intake. All the tea samples showed antioxidant activity: flowers – 66.7%, leaves – 62.3%, and blend – 52.5%. In terms of ascorbic acid, it was 69, 64, and 52 μmol/g dry matter, respectfully. The same samples demonstrated antiradical activity. Conclusion. Common buckwheat grass can serve as a raw material for tea beverages. Buckwheat tea is a natural functional food product with zero caffeine. They have a pleasant taste and aroma. They owe their high biological activity to the high content of rutin and other polyphenol compounds.
Introduction. The development of new technologies of bacterial cultures for fish products is an important area of re-search. Sodium chloride (NaCl) has an inhibitory effect on most microorganisms and is often used in fish industry. The present research objective was to study the effect of NaCl on the growth of lactic acid bacteria of the species Lactoba-cillus sakei. Study objects and methods. The research featured strains of lactic acid bacteria L. sakei (L. sakei LSK-45 and L. sakei DSM 20017). The bacteria were cultivated in a semi-liquid MRS medium supplemented with sodium chloride at vari-ous concentrations. The optical density (OD) of the medium and the viable cell counts served as indicators of bacterial growth. The morphology of bacterial cells was studied by microscopic examination of Gram-stained bacteria. Results and discussion. Both L. sakei strains proved tolerant to NaCl concentrations up to 6% as proved by the high density of the cell population – 109 CFU/cm3. When NaCl concentration reached 10%, L. sakei LSK-45 demonstrated the highest resistance to osmotic stress. At the end of cultivation, the population density dropped to 108 CFU/cm3, and the survival rate was 92%. The number of viable cells of L. sakei DSM 20017 decreased to 106 CFU/cm3, and the sur-vival rate reached 62%. The high resistance of L. sakei LSK-45 to osmotic stress was caused by cell cohesion, which increased with the growing NaCl concentration and was regulated by the quorum sensing system. Conclusion. L. sakei showed a flexible response to the changes in NaCl concentration. L. sakei LSK-45 strain had the highest resistance to osmotic stress.
Development of Lactic acid Microorganisms during Fermentation of Substrate with an Increased Concentration of Carbohydrates
Introduction. Creating favorable conditions for the development of lactic acid microorganisms is one of the main factors in obtaining high-quality fermented products. The cycle of their life directly depends on the amount and composition of carbohydrates in plant tissue. Since a significant part of carbohydrates is consumed at the initial stage of fermentation process, additional fortification is needed. The research objective was to study the development rate of lactic acid microorganisms during the fermentation of plant substrate with a modified carbohydrate composition. Study objects and methods. The research featured model medium based on white cabbage of the Parus variety. The medium was fermented with different strains of lactic acid microorganisms: at the first stage of fermentation – Leuconostoc mesenteroides, at the second stage – Lactobacillus casei VKM 536, Lactobacillus plantarum VKM B-578, Lactobacillus brevis VKM B-1309, and their paired consortia. The initial plant material was subjected to grinding and removal of native microflora for the development of target lactic acid microorganisms, then inoculated with L. mesenteroides. The target lactic acid microorganisms were introduced after the first stage of fermentation with simultaneous adjustment of the carbohydrate composition. Results and discussion. The technology included modes of controlled two-stage microbial transformation of plant raw materials using modification of the carbohydrate composition of the substrate. A number of experiments made it possible to select the optimal composition of the consortium and establish the optimal fermentation time at the main stage of microbial processing. When the plant substrate was fermented by the consortium of L. casei + L. plantarum with an increased carbohydrate component, the decrease in the concentration was quite small: after 5–30 days, the decrease in the concentration of microorganisms did not exceed one order of magnitude, which was insignificant at an initial concentration of eight orders of magnitude. In other consortia, the decrease in the concentration of microorganisms was more pronounced. Conclusion. The fortification of the vegetable substrate with carbohydrates made it possible to maintain the concentration of lactic acid microorganisms at a level comparable to the concentration at the time of inoculation. The concentrations of microorganisms varied slightly in both monocultures and their paired consortia during the entire main fermentation stage of the model medium with a modified carbohydrate component. By the end of the main fermentation stage, the concentration of microorganisms did not fall below 107 CFU/g. Therefore, the resulting system “microflora – substrate” proved to have probiotic properties. The study can be used to develop new technological modes of controlled step-by-step fermentation of plant raw materials in order to improve the quality indicators of the final product.
Introduction. Artificial neural networks are a popular tool of contemporary research and technology, including food science, where they can be used to model various technological processes. The present research objective was to develop an artificial neural network capable of predicting the content of isogumulone in a hop extract at given technological parameters of the rotary pulse generator. Study objects and methods. The mathematical modeling was based on experimental data. The isogumulone content in the hop extract I (mg/dm3) served as an output parameter. The input variables included: processing temperature t (°C), rotor speed n (rpm), processing time (min), and the gap between the rotor teeth and stator s (mm). Results and discussion. The resulting model had the following parameters: two hidden layers, 30 neurons each; neuron activation function – GELU; loss function – MSELoss; learning step – 0.001; optimizer – Adam; L2 regularization at 0.00001; training set of four batches, 16 records each; 9,801 epochs. The accuracy of the artificial neural network (1.67%) was defined as the mean relative error. The error of the regression model was also low (2.85%). The neural network proved to be more accurate than the regression model and had a better ability to predict the value of the output variable. The accuracy of the artificial neural network was higher because it used test data not included in the training. The regression model when tested on test data showed much worse results. Conclusion. Artificial neural networks proved extremely useful as a means of technological modeling and require further research and application.
The Effect of Replacing Sucrose with Glucose-Fruit Syrup on the Quality Indicators of Plombières Ice-Cream
Introduction. As functional products with a low glycemic index are becoming more and more popular, sucrose is gradually leaving food formulations. Glucose-fructose syrups (GFS) serve as substitutes for sucrose because they have a low glycemic index. The present research objective was to prove that GFS can be used for industrial production of functional foods, e.g. Plombières ice-cream with a low glycemic index. The list of technologically significant quality indices to be studied included dynamic viscosity, overrun, thermal and dimensional stability, and dispersion of the air phase and ice crystals. The experiment confirmed the synergistic effect of the mass fraction of fat and GFS on the dynamic viscosity, thermal and dimensional stability of the product, and a decrease of cryoscopic temperature. Study objects and methods. The research featured Plombières ice-cream. The control sample had a mass fraction of sucrose 14%; the experimental samples had a partial (3 and 5%) and complete replacement (14%) of sucrose. Rheological research methods helped to determine the dynamic viscosity; thermometric methods were used to measure the cryoscopic temperature of the mix and the temperature at unloading ice cream from the freezer, weighing methods – to determine the overrun, thermostatic methods – to establish thermal and shape stability, calculating methods – to define the share of frozen water, glycemic index, glycemic load, and sweetness. Results and discussions. The glycemic index of the test samples was 38–57, of the control sample – 60. The glycemic load per portion of 70 g was 5.3–7.8 (8.5 for control). The dynamic viscosity of ice cream mixes was 580–640 mPa·s (control – 563 mPa·s), the cryoscopic temperature –2.52–3.48°C, (control –2.32°C), and the temperature of unloading of the ice cream from the freezer at the share of frozen water of 50% was –5–7°C (control –4.6°C). As for thermal stability, after 90 min, the mass fraction of melt in the control sample was 35%, while in the sample with a complete replacement of sucrose, it was only 2%. In all the test samples, the structural elements had almost the same size. The diameter of air bubbles did not exceed 30 µm after hardening; the average size of ice crystals was 30–34 µm. The experimental data revealed no negative effect of replacing sucrose with GFS on the quality indicators of Plombières ice-cream. Conclusion. Glucose-fructose syrups can completely or partially replace sucrose while maintaining the quality parameters of Plombières ice-cream, e.g. dynamic viscosity, thermal and dimensional stability, dispersion of the air phase and ice crystals. The glycemic index decreased 1.6 times with a complete replacement of sucrose. Therefore, GFS can lower the glycemic index of Plombières ice-cream.
Carreau's Rheological Model and A.N. Tikhonov’s Regularization Method: Parametric Identification Based on a CFD model
Introduction. Carreau's rheological model can describe the three-dimensional flows of non-Newtonian media. However, it requires modeling parameters for the viscosity of the medium at the limiting values of shear rates, which cannot be achieved by instrumental methods. The present article introduces a novel method that can identify the parameters of Carreau’s model using a regularization algorithm. Study objects and methods. The study featured fondant mass produced according to the traditional formulation for Creamy Fondant unglazed candies. Standard methods were used to describe the properties of the raw materials and semi-finished products, as well as methods of mathematical processing, modeling, and optimization. Results and its discussion. The research produced an algorithm based on A.N. Tikhonov’s regularization method of the parametric identification of Carreau's rheological model. The calculation residual was minimized by the viscometric measurements and the CFD model, which provided the calculation of the hydrodynamic flow regime at the limiting values of shear rates. The CFD model of a steady non-isothermal flow of a nonlinear viscous medium through a cylindrical capillary was based on the equations of conservation of mass, energy, and momentum. The rheological parameters of Carreau’s model were illustrated by the case of fondant mass. The error for the viscosity prediction did not exceed 14.07%. Conclusion. The parametric identification algorithm made it possible to evaluate the rheological parameters of structured liquid media with Carreau's rheological law in cases that lack experimental information on the behavior of the medium at limiting shear rates. The algorithm eliminated the computational problems typical of Ostwald and de Ville’s rheological model, which usually arise when solving practical problems of three-dimensional flows of non-Newtonian media with limiting viscosity values.
Introduction. The research featured the effect of various hopping conditions on the content of polyphenolic compounds associated with the extraction and biotransformation of hop compounds. This mechanism is responsible for uncharacteristic beer flavor in the traditional production method. The research objective was to study the migration routes, influence factors, and changes in the content of hop polyphenols in model experiments in order to reduce various factors in the production process chain. The experiment was important from the point of view of identifying the polyphenols contribution to the beer colloidal system. Study objects and methods. The study involved granulated aromatic hop of Tetnanger variety harvested in 2019, aqueous and 4% aqueous-alcoholic solutions simulating the wort and young beer liquid phase, and brewing yeast Sacharomyces cerevisiae of races Rh (lager) and Nottingham (ale). The work used the generally accepted methods for assessing the content of polyphenolic compounds. Results and discussion. The research established various factors that affected the migration of hop polyphenolic groups. The acidity effect on the polyphenol was established as follows: pH 4.4 contributed to a 12% greater isoxanthohumol accumulation, while pH 5.2 promoted a six times greater accumulation of anthocyanogens than pH 4.4. The total content of polyphenols during boiling was constant and correlated with the phenolic compound in different groups. The conditions of “dry” hopping, simulating the wort clarification in Wirpool, increased the dissolution of anthocyanogens by six times in comparison with kettle hopping, which was associated with the turbulent flow. The isoxanthohumol sorption and formation rate during “dry” hopping was established when modeling the maturation conditions for different temperatures, oxygen levels, and yeast races. A lower temperature (5°C) had a negative effect on the isoxanthohumol sorption. The quercetin content was found to be in the range of 0.9–2.0 mg/dm³ at 5°C and 0.8–4.7 mg/dm³ at 20°C, which determined the temperature effect on extraction during “dry” hopping. The presence of yeast cells in the medium promoted the quercetin accumulation: the quercetin content doubled at 5°C and quadrupled at 20°C compared with the control. The rutin content in the control increased for two days, and minor fluctuations in the content of yeast cells were 5.0 ÷ 7.4 mg/dm3. A comparative analysis of the simple phenolic acids and aldehydes amounts under “dry” hopping conditions showed a greater decrease in their concentration because they were involved in the yeast consumption and biotransformation processes. Conclusion. The research made it possible to establish the phenolic compounds in various groups of migration routes under the conditions of classical (kettle) and “dry” methods of hopping, as well as their dependence on such factors as medium acidity, stirring intensity, temperature, oxygen content, and yeast race. The sorption rates of the polyphenolic compounds were established as follows: absorption of isoxanthohumol was at its highest during the first day of “dry” hopping, and that of rutin – within two days, while quercetin was not absorbed at all. Therefore, an additional fermentation stage can be considered as the most expedient method of “dry” hopping.
Introduction. Whey drinks, fruit nectars, and reconstituted juices are usually based on domestic water. This water may contain various contaminants, which can interact with vitamins in fruit drinks. The research objective was to study the impact of trichloromethane, hydroxybenzene, chlorophenol, trichloroethylene, and ethylene chloride on the state of vitamins in juice products. Study objects and methods. The study featured aqueous fruit and berry concentrates, used in fruit nectar production. The control sample contained water without contaminants, while the test samples involved trichloromethane, trichloroethylene, ethylene chloride, hydroxybenzene, and chlorophenol. Capillary zone electrophoresis made it possible to determine bioactive substances (vitamins) in aqueous fruit and berry concentrates. Molecular absorption spectroscopy in visible spectrum was used to check the color intensity. Gas chromatography helped to analyze the content of contaminants. Results and discussion. The experiment tested vitamin preservation in fruit nectars based on water contaminated with trichloromethane, trichloroethylene, ethylene chloride, hydroxybenzene, and chlorophenol. Trichloromethane did not react with bioactive substances. Trichloroethylene, ethylene chloride, hydroxybenzene, and chlorophenol lowered the content of ascorbic acid, carotene, thiamine, riboflavin, choline, and pyridoxine. Depending on the organic matter, water contamination led to a decrease in carotene by 7–35%, vitamin B1 – by 10–100%, B2 – by 11–100%, B4 – by 8–45%, and B6 – by 8–100 in the finished product. The paper introduces a theoretic substantiation of the interaction between the contaminants and the bioactive substances. Conclusion. Water, contaminated with such organic substances as hydroxybenzene, chlorophenol, trichloroethylene, and ethylene chloride, proved to affect the vitamin preservation in juices, which was illustrated by chemical equations. Therefore, juice production requires preliminary water purification because toxic and cancerogenic substances can decrease the quality and food safety of the finished product.