Volume 55, Issue 3, 2025

Removing moisture from biological materials has many advantages since reduced volume means lower processing costs, and drying prevents microbial growth and spoilage. Despite the fact that different drying methods pursue the same goal, they differ conceptually and require modification/adaptation, depending on the biomaterial. The article describes the kinetics and optimal dehydration modes that increase the drying efficiency of quasi-liquid products (roe and skein complex) using physical and mathematical modeling of heat and mass transfer and moisture removal. The existing mathematical model for drying with combined energy supply was adapted to fish eggs and lecithin clot. The dehydration kinetics made it possible to understand the temperature distribution inside the dried biomaterial and estimate the drying time. A gas mix served as a drying agent. The calculations were compared with the experimental drying tests for similar biomaterials. The materials were subjected to dehydration in the mode of conductive-convective heat supply in an original laboratory drying unit. The authors identified the kinetic patterns and rational mode parameters to increase the performance. The rational operating parameters included the intensity of the coolant movement (3.50 m/s); the height of the dried layer (0.01 m); the surface temperature of the dried material and the temperature of the heating plate (313 K); the initial temperature (283 K); the final moisture content (0.10 kg/kg). Under these parameters, the specific productivity was 7.610 kg/(m2·h), and the drying time to 0.1 kg/kg humidity was 150 min. The rational operating parameters of the lecithin clot included the coolant feeding rate (2.50 m/s); the layer height (0.003 m); the surface temperature of the dried material and the temperature of the heating plate (343 K); the initial temperature (328 K); the final humidity (0.130 kg/kg). In this case, the specific productivity was 13.630 kg/(m2·h), and the drying time to 0.130 kg/kg humidity was 40 min. Heat and mass transfer modeling increases the accuracy of calculation, making it possible to realize the energy saving potential without preliminary experiments while maintaining the quality of the dried product. In this research, the kinetic patterns, optimal dehydration modes, and drying models can be applied to heat and mass transfer processes under different production conditions, as well as to design new drying units for fish eggs and lecithin curd.

Food dyes are widely used in the food industry to improve the sensory properties and consumer attractiveness of finished products. However, synthetic dyes are associated with potential health risks. Microalgae are known to produce natural pigments that provide intense coloring and possess various biological metabolites, e.g., chlorophylls and carotenoids. This article reviews available data on the pigment composition of Scenedesmus microalgae, including cultivation strategies, efficient pigment biosynthesis, prospects for the functional food and nutraceutical industries, and commercial limitations. The review covered scientific publications on Scenedesmus colorants, their bioactive properties, and / or practical application registered in ScienceDirect (Scopus), Springer Link, MDPI, and Google Scholar in 2015–2025. Scenedesmus microalgae accumulate significant amounts of chlorophylls (≤ 30.8 mg/g) and carotenoids (≤ 98.0 mg/g). The carotenoid profile of Scenedesmus consists of a variety of compounds, with such commercially important substances as lutein (≤ 10.7 mg/g), β-carotene (≤ 19.0 mg/g), and astaxanthin (≤ 23.8 mg/g). Scenedesmus carotenoid extracts possess antimicrobial, antiproliferative, hypolipidemic, and antidiabetic properties. As a result, Scenedesmus pigments are promising components to be used in functional foods and nutraceuticals. Various cultivation strategies aim at increasing the pigment yield in Scenedesmus biomass. Two factors hinder the successful commercialization of Scenedesmus for pigment production: 1) pigment composition depends on the strain and cultivation conditions; 2) large-scale pigment cultivation and extraction are technically and economically complex. Further research is required to assess the safety and bioavailability of Scenedesmus pigments, as well as to improve industrial cultivation and extraction technologies.

Antioxidants protect living organisms from free radicals, as well as prevent the destruction of lipids and other nutrients. Natural alternatives to synthetic antioxidants can extend the shelf-life of food products and improve consumers’ health. Extracts of Rosaceae berries are known for their antioxidant properties and have a good potential as food stabilizers; however, their efficiency may depend on the region. The research featured ethyl acetate extracts from mountain ash berries (Sorbus aucuparia L.), blood-red hawthorn (Crataegus sanguinea Nutt.), and black hawthorn (Crataegus nigra Waldst. & Kit.), harvested ripe in the south of the Republic of Armenia. The kinetic modeling of cumene oxidation (348 K) made it possible to determine the antioxidant activity. The experiment involved a manometric installation with automatically regulated pressure that recorded oxygen absorption in the reaction mix. The blood-red hawthorn extract demonstrated the highest antioxidant activity (k7 ≈ 5.5×10⁻3 L/mol·s), exceeding the mountain ash indicators (k7 ≈ 2.3×10⁻³ L/mol·s) by 2.5 times. The effective concentration of antioxidants in the mountain ash extracts was slightly higher (3.8 mol/L) than in the blood-red hawthorn extract (3.5–3.8 mol/L). The black hawthorn extract showed much lower indicators in both antioxidant content (0.66 mol/L) and activity (2.4×10–4 L/mol·s). However, the oxidation products of black hawthorn antioxidants exhibited a strong antioxidant activity (k71 = 6.48×10² L/mol·s), almost three times higher than the corresponding indicator for the blood-red hawthorn sample. The ethyl acetate extracts of blood-red hawthorn (Crataegus sanguinea Nutt.) and mountain ash (Sorbus aucuparia L.) proved to be effective natural antioxidants that could replace synthetic food stabilizers and extend shelf-life. Despite its low initial antioxidant activity, the black hawthorn extract (Crataegus nigra Waldst. & Kit.) might be recommended for specific food systems with prolonged protective effects.

The preservation of Vietnamese sea grapes (Caulerpa lentillifera) still faces major limitations due to their short shelf life and rapid deterioration of their sensory, aesthetic, and nutritional qualities. This results from commonly used NaCl brine rather than better alternative processing approaches. This study aimed to optimize the parameters for preserving Vietnamese sea grapes. In particular, we optimized dehydration and color fixation techniques to enhance their sensory quality and shelf life. Optimal conditions were identified as blanching at 90°C for 10 s, rapid cooling at 10–15°C, and soaking in a color-fixation solution (15% NaCl + 5% sorbitol) for 10–15 min. The treated sea grapes demonstrated a superior color quality compared to common commercial products, with the green color index of 117.93 ± 44.86 and color intensity of 94.32 ± 45.36. Other improvements included a possible shelf life extension by 4–6 weeks, a decrease of 20–25% in spoilage rates, and a reduction of 10–15% in preservation and transportation costs. This can increase the net profit by 15–20%, as well as improve the product’s efficiency and competitiveness. The developed method extends the shelf life of Vietnamese sea grapes, reduces their spoilage, and lowers preservation costs. This enables the product to meet international quality standards, enhancing its value and competitiveness. The remaining challenges include high initial investment, temperature control, staff training, and quality control systems. Future studies should identify changes in essential nutrients under long-term real-life transportation and storage conditions.

Wheat (Triticum aestivum L.) is the major grain crop that ensures global food security. Intensive farming often involves overuse of mineral fertilizers and pesticides, which leads to soil degradation and environmental pollution. Microorganisms and natural sorbents, e.g., zeolite, offer an alternative solution to the crop yield problem. Zeolite improves the soil structure while helping to retain moisture and nutrients. Growth-stimulating bacteria increase the availability of nutrients for plants and stimulate their growth. This research featured the effect of the combined use of zeolite and bacteria on different wheat varieties and growth indicators in laboratory conditions. The experiment involved spring wheat varieties of Sibirskiy Alyans, Pamyati Afrodity, and Nadezhda Kuzbassa. The list of growthstimulating bacteria included Azotobacter chroococcum B-4148, Azotobacter vinelandii B-932, and Pseudomonas chlororaphis subsp. aurantiaca B-548, as well as their consortium (1:3:1). The indicators to be checked included the solubilizing activity of the strains and the effect of zeolite (1 t/ha) and bacterial preparations on wheat growth. All bacteria solubilized zeolite (2.5–17.7 mm). The highest activity belonged to P. chlororaphis subsp. aurantiaca B-548 (17.7 mm). The combined application of zeolite (1 t/ha) and the bacterial consortium had a positive effect on the growth and development of all wheat varieties. The Sibirskiy Alyans variety showed a germination rate of 86%, a shoot length of 183 mm, a dry weight of 42.4%, a chlorophyll content of 24.47%, a carotenoid content of 16.21%, and a nitrogen concentration of 51.83%. The Pamyati Afrodity variety demonstrated 80% germination rate, 157 mm shoot length, 31.3% dry weight, 32.07% chlorophylls, 19.40% carotenoids, and 59.35% nitrogen. The Nadezhda Kuzbassa variety had 98% germination rate, 185 mm shoot length, 41.2% dry weight, 39.74% chlorophylls, 28.47% carotenoids, and 55.26% nitrogen. The results confirmed the i ndustrial efficiency of zeolite and bacteria in wheat farming, as did other reports on their positive effect on crop yield. However, further field trials are needed to confirm the results in conditions close to reality.

The current methods for detecting residual antibiotics and veterinary drugs in dairy products require more accuracy and a wider target range. Immunofluorescence demonstrates high potential, but its efficiency depends on the physical and chemical properties of the dairy product, e.g., mass fraction of solids, protein, and fat, pH, etc. This research featured the immune response of an immunofluorescence bioanalyzer to the physicochemical parameters of milk permeate, milk retentate, buttermilk, and cream in order to establish the limits of determination of residual antibiotics. The experiment involved whole standardized milk, raw whole milk, skim milk, whole milk powder, skim milk powder, cream, milk permeate, milk retentate, buttermilk, and their composite systems. All samples were tested for residual veterinary drugs and physicochemical profile (five replications). The data obtained were processed in Unisensor S. A., Wolfram Mathematica, and Microsoft Excel (Solver and Data Analysis add-ins). A simultaneous consideration of the specified parameters minimized the probability of false negative and false positive results in detecting residual veterinary drugs. The approach increased the analytical accuracy and reproducibility. The research yielded a universal algorithm for adapting immunofluorescence analysis to various types of dairy products. This algorithm provided accurate determination of residual amounts of antibiotics in raw milk, buttermilk, permeate, retentate, cream, and processed dairy products, which indicated its practical significance in dairy quality control. If implemented on commercial scale, the new method will improve the current dairy safety standards, strengthen consumers’ trust in the domestic dairy industry, and improve their health.

As the range of domestic cheeses has increased, Russian cheese industry needs new monospecific starters with multidirectional or targeted actions. Advanced monospecific concentrates with strong proteolytic properties boost proteolysis, reduce ripening time, and improve the sensory profile of the finished product. This article describes some strains of mesophilic lactobacilli with good prospects for commercial cheese production. The lactobacilli strains were isolated from the collection of microorganisms of the All-Russian Scientific Research Institute of Butter and Cheese Production, Uglich, Russia. They included Lactiplantibacillus plantarum 28 and 37, Lacticaseibacillus casei 738-11, Lacticaseibacillus paracasei K-6, Lacticaseibacillus rhamnosus P, and Limosilactobacillus fermentum 39. The proteolytic profile was estimated by the amount of accumulated non-protein nitrogen and the buffer capacity of the water-soluble fraction. The skim-milk cultivation revealed two optimal strains with the highest proteolytic effect, i.e., L. rhamnosus P and L. paracasei K-6. They served as additional cultures to the main industrial starter. L. rhamnosus P accumulated biomass faster during processing and pressing; L. paracasei K-6 developed more intensively during ripening. The highest count of viable lactobacilli cells reached 8.55 lg CFU/g in the cheese samples with L. rhamnosus P and 8.94 lg CFU/g in the samples with L. paracasei K-6. L. rhamnosus P died slower and demonstrated a stimulating effect on lactococci. The high content of lactobacilli in the experimental cheeses (≥108 CFU/g) made it possible to classify them as dairy probiotics. The samples with L. paracasei K-6 and L. rhamnosus P proved to be more active proteolytics. By the end of ripening, the experimental samples contained 20% more non-protein nitrogen than the control. The cheeses fortified with L. paracasei K-6 received the highest score for taste and aroma, which correlated with the greatest change in the buffer capacity of the watersoluble fraction. L. paracasei K-6 and L. rhamnosus P in monospecific starters proved able to improve the quality of cheese and intensify its production.

Dairy products can be fortified with new valuable strains of probiotic lactobacilli. This research tested two new lactobacilli strains for prospects in sour-cream butter production. The lactobacilli strains of Lactobacillus plantarum and Enterococcus hirae were selected at the Research Institute of Biotechnology, Gorsky State Agrarian University. The study also involved a symbiotic starter based on these strains, cow’s milk cream, and sourcream butter. The quality indicators were assessed using a Klever milk analyzer and a set of standard methods: physicochemical indicators for the cream, clot formation rate and pH for the lactobacilli, and sensory, physicochemical, and microbiological indicators for the butter. The study revealed the sensory and physicochemical profile of the cream, the curding rate and the pH rate of the sour-cream during cultivation, and the physicochemical parameters of the resulting sour-cream butter. It took the symbiotic starter of L. plantarum and E. hirae (1:1) 6 h to curd at an acidity of 68.00 °T; L. plantarum curded in 6 h at 56.00 °T; E. hirae curded in 7 h at 65.00 °T. The maximal acid-forming capacity of L. plantarum was 323 °T (6 days of incubation), that of E. hirae was 170 °T (5 days), and that of the symbiotic culture was 220 °T (4 days). The technology of producing sour-cream butter included pasteurization, cooling, heating, adding starter (L. plantarum and E. hirae), churning, processing butter granules, and shaping. The sour-cream butter sample produced with the symbiotic starter contained 25.2% moisture and 71.4% fat; it had a caloric value of 665.0 kcal. It was yellow, dense, and shiny, with a characteristic sour-cream taste and smell. The experimental sour-cream butter demonstrated excellent sensory indicators and could be recommend for industrial production with strains of L. plantarum and E. hirae in a ratio of 1:1.

Bacterial cellulose differs from plant cellulose: its unique properties include a strong crystalline nanostructure and a high degree of polymerization. In addition, it is more pure than traditional cellulose as it contains neither lignin nor hemicellulose. These qualities make it a promising alternative to plant cellulose in several industries. Bacterial cellulose with the specific physicochemical profile can be obtained only if the metabolizing properties of its producer have been considered. This article describes the effect of nutrient medium compositions with different carbon sources, vitamins, mineral salts, and acids on the yield and properties of bacterial cellulose. Acetic acid bacteria Acetobacterium xylinum B-12429 were cultivated statically at 28°C for 72 h on the Hestrin-Schramm medium with varying carbon sources and growth factors. The highest biomass yield (4.4 g/L) was obtained on cultivation day 10 in the sample with 20.0 g/L fructose. Glucose provided a lower productivity of 3.6 g/L. The bacterial cellulose yield also proved to depend on the concentration of the main carbon source: it was at its maximum at 10%. Adding ascorbic acid and MgSO4 also catalyzed the biosynthesis. The structural profile was studied using infrared spectroscopy and scanning electron m icroscopy. It included such physicochemical properties as water-holding capacity and crystallinity indices Iα and Iβ. The biofilms produced from the media fortified with xylose and sorbitol demonstrated excellent water-holding capacity; all the samples demonstrated a stable crystalline structure regardless of the carbon source. The composition of the nutrient media had a significant effect on the yield and quality of biosynthesis. An optimized nutrient composition was able to boost biosynthesis, making the method applicable to industrial scales of high-quality bacterial cellulose production.

Synthetic food packaging remains a looming environmental hazard. Biodegradable alternatives from renewable natural raw materials may be a solution to this problem. Edible packaging films can be produced from fish waste gelatin and seaweed sodium alginate. They combine environmental benefits with the functional characteristics required by the food industry. This article introduces a new environmentally friendly packaging film and its physicochemical profiles depending on the ratio of cold-water fish waste and sodium alginate. The experiment also included selecting the optimal type and concentration of plasticizer for safe and long food storage. The experimental films consisted of different mixes of cold-water fish skin gelatin, brown algae sodium alginate, and glycerol or sorbitol. The films were tested for thickness, moisture content, vapor permeability, moisture absorption, tensile strength, flexibility, and thermal properties. Optical microscopy, IR spectroscopy, and differential scanning calorimetry made it possible to analyze the structure, physicochemical properties, and thermal stability. The statistical processing relied on the Student’s t-test method. An optimal ratio of components yielded films with improved mechanical and barrier properties, low hygroscopicity, low vapor permeability, and high melting temperatures (135–138 °C). The samples with sorbitol as plasticizer demonstrated a more uniform structure, resulting in low vapor permeability (829–1,122 g/m2), reduced moisture absorption (≤ 98%), and high tensile strength. The samples with glycerol had better plasticizing properties, but higher vapor permeability (1,572–1,895 g/m2) and moisture absorption (114–179%). The established patterns may help to control the properties of industrial biopolymer compositions by adjusting the type of plasticizer and the concentration and ratio of components to obtain novel food films with improved mechanical characteristics and low hygroscopicity.

Galacto-oligosaccharides are known for their prebiotic activity. They are obtained from lactose using bacterial or fungal betagalactosidases. This article describes the factors that affect the biosynthesis and purification of galacto-oligosaccharides using Kluyveromyces yeasts, as well as summarizes some prospective research areas in this sphere. The research covered ten years of scientific publications on the production of galacto-oligosaccharides with yeast beta-galactosidases. The review pool included 87 articles published in peer-reviewed journals and registered in Scopus, Web of Science, PubMed, and eLIBRARY.RU. The yield, composition, and properties of galacto-oligosaccharides depend on the enzyme, its application, biosynthesis optimization, and purification conditions. Beta-galactosidases from Kluyveromyces can simultaneously catalyze hydrolysis and transgalactosylation reactions. The biosynthesis conditions vary a lot across the review pool, as does the yield of galacto-oligosaccharides, which usually remains below 30–40% while the total lactose conversion reaches 80–90%. Kluyveromyces beta-galactosidases can be used as whole-cell enzymes in immobilized form or together with other enzymes. They improve the economic indicators of biosynthesis, and / or the yield and / or the structure of galacto-oligosaccharides. If synthesized directly in milk or whey, galacto-oligosaccharides may yield new functional dairy products and additives. The method of selective bioconversion with Kluyveromyces yeast brings the purity of galacto-oligosaccharides up to 90% in an economical and sustainable way. Eventually, galacto-oligosaccharides can be obtained from dairy by-products. Other promising areas include the enzymic mixes of different producers, as well as a comprehensive use of Kluyveromyces beta-galactosidases for galacto-oligosaccharide biosynthesis and purification.

Yeast cultures with advanced metabolic indicators improve various industrial biotechnological processes. New sources of biostimulators involve mainly natural resources, e.g., Taraxacum officinale Wigg. or Trifolium pratense L., as well as non-destructive extraction methods, e.g., supercritical fluid extraction (SCFE). This research featured the effect of CO2 extracts of T. officinale and T. pratense on the enzymatic and physiological profiles of yeast culture. The experiment involved CO2 extracts of T. officinale and T. pratense obtained by SCFE at 8.0–20.0 MPa and 40°C, as well as industrial brewer’s yeast. The method of gas chromatography made it possible to reveal the chemical composition of the extracts while the Warburg method revealed the fermentation activity of the yeast. The rational parameters of SCFE for T. officinale included a working pressure of 15.0 MPa while for T. pratense it was 8.0–15.0 MPa. The separate fractions of CO2 extracts obtained with SCFE differed in many aspects. The appearance varied from liquid to waxy. The refractive index correlated with the working pressure. The chemical composition was represented by different mixes of hydrocarbons, phenolic compounds, fatty acids, ketones, aldehydes, and alcohols. The bioactive potential demonstrated antibacterial, antioxidant, and other properties. The analysis involved the chemical composition of the CO2 extracts during longterm storage based on spectrograms and chemical composition. It showed a decrease in the concentration and transformation of polyphenols, flavonoids, and other essential oil components. The microbiological profile of the CO2 extracts was as follows: on storage day 30 at 20–24°C, they contained gram-negative bacteria. However, no microflora was detected when the storage conditions were 2–4°C in the dark. The initial extracts were also microflora-free. When treated with aqueous solutions of CO2 extracts of T. officinale and T. pratense for 20–30 min in an amount of 0.2–2.0% biomass volume, the yeast increased their fermentation activity by an average of 220% while the dead cell count went d own. In this research, the CO2 extracts of T. officinale and T. pratense demonstrated good prospects as industrial yeast biostimulators.

Lactic fermentation is one of the oldest biotechnologies. The modern dairy industry requires new starter cultures to obtain products with target properties and qualities. This review systematizes scientific publications on advanced biotechnological solutions in the field of database formation and prediction of the properties of lactic acid microorganisms, as well as on the isolation and selection of cultures with optimal industrial qualities. The review included publications in Russian and English registered in Scopus, Google Scholar, and eLIBRARY.RU in 1999–2024. The industrial value of strains depends on their biochemical activity, fermentation rate, resistance to salts and acids, and the range of biologically active compounds they are able to synthesize. Novel lactic acid strains create active industrial consortia for functional products with probiotic properties. The modern principles of biocompatibility assessment for multicomponent microbial consortia include species authenticity, inter-consortium synergism, safety for human microflora, and combinability with prebiotics, microelements, vitamins, and antioxidants. Genetic engineering is another advanced option: it provides targeted modification of the metabolic pathways of the producer. It is more efficient than conventional methods and decreases the cost of the product. Domestic industrial production of probiotic starter cultures ensures food security and technological independence, as well as improves the national health.

The man-induced impact caused by agriculture and industry depletes the biosphere and its resources. Sorption is an effective means of removing heavy metals from water. This research featured manganese adsorption patterns in surface, underground, and wastewater sources. The study involved conventional activated carbon SKD-515, a coconut carbon sorbent, and a mineral sorbent of MS brand. The surface structure was studied using the methods of X-ray structural analysis, electrothermal atomic absorption spectrometry, and scanning electron microscopy. Other experiments tested the results of manganese adsorption under different equilibrium, kinetic, and dynamic conditions. The tests revealed an insignificant change in the structural and sorption parameters. The samples of coconut carbon and SKD-515 were microporous while the MS sample proved to be mesoporous. The static test made it possible to range the sorbents by their absorption capacity as follows: MS > coconut carbon > SKD-515. According to the kinetic test, the limiting stage of the adsorption process started at the external diffusion mass transfer (20–45 min). The modeling stage involved a sorption column with a fixed material bed and different column diameters, loading layer heights, flow rates, and initial concentrations of manganese ions. Under dynamic conditions, the highest purification degree (87%) belonged to the MS samples followed by the coconut carbon samples (45%) and the conventional SKD-515 material (37%). The MS mineral sorbent proved to be the most effective manganese sorbent under static, kinetic, and dynamic conditions, demonstrating good prospects as a cheap industrial wastewater and natural water filter.

Microbiological indicators make it possible to reveal potential safety risks in the dairy industry. Bacteriophages affect the lysis of starter cultures because they can disrupt fermentation processes in dairy production. This study featured the seasonal factors that affect the phage status during dairy fermentation, the newly isolated bacteriophages, and the defense systems used by lactococci strains. The research featured raw milk, cream, and skim milk; whole and skim milk powders; curd and cheese whey; strains of lactococci from different species with different phage resistance (Uglich Biofabrika Ltd; Bioresource Center of All-Russian Collection of Industrial Microorganisms); two new bacteriophages ph. 1622 and ph. 1623. The research relied on a number of standard microbiological, genetic, and mathematical methods. The mesophilic aerobic and anaerobic microbial count was performed by inoculation on a dense nutrient medium (State Standard GOST 32904-2014) while the two-layer inoculation method revealed the bacteriophage titer. The genomic DNA analysis involved a phenol–chloroform extraction followed by precipitation with isopropanol and electrophoretic separation in agarose gel. The experiments yielded reliable data on the quantitative change of phage particles in the raw material, the seasonal variability of mesophilic lactococci phages, and the genetics of the new industrial bacteriophages. The highest count of phage particles belonged to the samples obtained in the summer whereas the lowest was associated with the winter samples. The count of phage particles correlated with the bacterial contamination of the samples. The phage resistance index in Lactococcus lactis subsp. lactis, L. lactis subsp. cremoris, and L. lactis subsp. lactis biovar. diacetylactis had a seasonal character, the highest variability being recorded in L. lactis subsp. lactis, i.e., an acid former of starters. The DNA and amino acid sequences of phage proteins in phages ph. 1622 and ph. 1623 isolated from industrial samples made it possible to create panels of phage alternative strains. The seasonal variability in lactic acid bacteria cultures and bacteriophage activity may affect the quality and safety of dairy products. The DNA of ph. 1622 and ph. 1623 differed in restriction patterns, which means they were distinct phages. Comparative genomics revealed their similarity to the well-known L. lactis-infecting c2 phage. The new phages exhibited different lactococcal cell infection mechanisms. The ph. 1623 genome insertion encoded an orphan DNA methyltransferase that could potentially suppress bacterial immune systems. Further research may reveal lactococcal phage sensitivity and defense mechanisms.

Hydrolyzed collagen modifies the structure of cheese spreads: it develops a hybrid casein-collagen matrix and stabilizes the fat emulsion. This research featured the effect of hydrolyzed collagen on the microstructure and rheology of cheese spreads. The study involved experimental cheese spread with 3.1% hydrolyzed collagen and a collagen-free control sample. The method of optical microscopy and image analysis (Fiji ImageJ2) made it possible to study the microstructure. The rheological profile was investigated on an experimental Reokon tensile strength tester with a knife indenter. Hydrolyzed collagen improved the structural and mechanical properties of the finished product. As the protein matrix grew more compact and the fat emulsion became more stable, the average size of fat globules dropped from 26.5 to 14.8 μm without coagulating or clustering. In addition, the porosity of the protein matrix reduced by 20% while the aqueous phase distribution became more homogeneous. Hydrolyzed collagen improved the adhesion and viscosity properties of the experimental cheese spread by 40% but not its tensile strength. As a result, viscosity prevailed over elasticity, and the experimental cheese spread retained its plasticity. Hydrolyzed collagen proved to be an effective component in the formulation of cheese spreads that require high adhesion and plasticity. However, it is likely to spoil the targeted structural properties of smoked or sliced cheeses. The results open up new prospects for further optimization of the texture of domestic cheese spreads.

Pathogenic microorganisms cause food spoilage. Food science knows a number of methods to prevent it without compromising the original food quality. Plant extracts are effective and safe components that contain organic acids and polyphenols capable of inhibiting the growth of pathogenic microorganisms. This in-vitro research featured the antimicrobial and metabolomic profiles of plant extracts from the Kemerovo Region, Western Siberia, Russia, as well as their antiseptic and antimicrobial prospects. The aqueous-alcohol extracts of Heracleum sibiricum L., Pulmonaria officinalis L., and Syringa vulgaris L. in various concentrations (40, 55, 60, 70%) were tested for antimicrobial activity in vitro using the disc diffusion method. The method of high-performance liquid chromatography with a UV detector made it possible to identify the metabolomic composition. The concentration was calculated mathematically, by calibration equations (3–5% mean error). The extracts of H. sibiricum, P. officinalis, and S. vulgaris demonstrated different antimicrobial activities. The broadest range belonged to the 40 and 60% aqueous-alcoholic extracts of H. sibiricum, which were able to inhibit Escherichia coli, Enterococcus faecalis, Pseudomonas putida, and Pseudomonas aeruginosa. These extracts also contained coumarin compounds that destroyed cell membranes and prevented biofilm formation. P. officinalis inhibited Bacillus cereus and P. aeruginosa. The test samples of S. vulgaris contained anthocyanins and organic acids that served as natural preservatives while inhibiting Candida albicans and E. coli. Siberian H. sibiricum, P. officinalis, and S. vulgaris proved to contain a wide range of bioactive compounds that could be used to develop new natural antiseptic and antimicrobial drugs. Despite the confirmed antimicrobial activity, the extracts of these plants require further research to be used in the food industry. So far, their safety status, stability, effect on food sensory profile, and interaction with other ingredients remain unknown.