INTRODUCTIONMicroorganisms have long been widely used in thefood industry: in winemaking and beverage production,dairy production, silage making and fermentation ofplant materials, as well as in seafood fermentation [1–17].Products of animal origin make up a significantpart of total food consumption. Like any products, theyundergo biochemical transformations during productionand are exposed to microorganisms during long-termstorage [18–19].Literature describes various methods for producingfoods under the influence of microorganisms containedin animal raw materials. One of such methods – aging– is mainly used to produce dry-cured products. Thisprocess involves curing raw materials and semi-productsunder certain conditions to expose them to a gradual,and sometimes fairly long, effect of the microorganisms’enzyme systems. As a result, the main food componentstransform and develop certain flavoring characteristics[20–22].Today, formulators forcibly introduce starter culturesof microorganisms into raw materials to reduce processtime. In particular, for food systems based on animalraw materials, they use Staphylococcus (St. xylosus,St. carnosus), Lactobacillus (L. pentosus, L. plantarum,L. sakei, L. curvatus), and Pediococcus (P. pentosaceus,P. acidilactici) [23–26]. Microorganisms canproduce different effects and form a wide varietyof flavors [27–28].For convenience, microorganisms are commonly usedas lyophilized solids, with culture cells deposited on thesurface of a solid carrier, usually sugars. For products ofanimal origin, 1–2 g of a freeze-dried culture containing(1–10)×1012 CFU/100 g sucrose is usually added per every5 or 10 kg of raw material [21, 29].Although the action of microbiological cultureson various food materials is fully described, scientificliterature lacks systematic data on the quantitativechanges in the most important minor components ofanimal materials (individual amino acids, fatty acids,and monosugars) under the influence of L. planta-rumand S. carnosus.We aimed to identify the effects of microorganismcultures on protein, lipid, and carbohydrate componentsof animal-based food systems.STUDY OBJECTS AND METHODSOur objects of the study included a model foodsystem – a mixture of beef muscle tissue Longissimusdorsi and pork fat tissue Telae adipem with 2% sodiumchloride (75:25%) homogenized in a Buchi Mixer B400blender (Switzerland), as well as a model protein. Themodel food system contained 18.5% protein, 23% fat,2.5% carbohydrates, and 54% moisture.The model protein was obtained by a 6 h extractionat 25°C of Longissimus dorsi of Bubulae beef with a 5%sodium chloride solution followed by desalting on G25and freeze-drying [30]. The isolated protein was 93%pure and had a 6% moisture.Lactobacillus plantarum ATCC 8014 (LP) andStaphylococcus carnosus ATCC 51365 (SC) were addedin an amount of 1×107 CFU/g of raw material. We usedpreparations of culture on freeze-dried sucrose in anamount of 2×1010 CFU/g.The model mixture was treated as follows. First,animal raw materials were kept in salt for 24 h at2 ± 2°С. Then, we introduced starter cultures and packedthe mixture in plastic bags to keep in the chamber for5 days at 2–4°С, relative humidity (W) 85%, and an airflow speed of 0.1 m/s. Further treatment was carriedout during 5 days (15°C, W 82%) and 10 days (12°C,W 75%). The control sample was kept in salt for 24 h at2 ± 2°C.The model protein was treated with starter culturesin a 2% sodium chloride solution (hydromodule 1:5)under similar conditions at pH 7.0.To measure the proteolytic activity, we placeda 1% casein solution in 0.05 M Tris-PO4 buffer(pH 7.0) into two tubes (5 mL in each) and added10 mL of distilled water to the first tube and 1 mL ofa 1×1010 CFU/mL enzyme solution or 1 mL of the testsolution to the second tube. After a 10-min exposureat 37°C, we added 5 Ml of a 10% trichloroacetic acidsolution to the test samples, filtered them through a0.45 μm filter, and measured the optical densities ofthe transparent solutions against the control at 280 nm.The proteolytic activity (units/mg) was calculated asA = (D280 sample – D280 control)/10·g, where g is thenominal enzyme concentration in the test sample. Thestandard unit of peptidase activity is the amount ofenzyme required to release free amino acids duringproteolytic decomposition. It is equivalent to a changein the absorption rate of the test solution (0.001D280) perminute at 37°C and pH 7.0 [31].The materials were treated with L. plantarum andS. carnosus in a 1:5 ratio: 1 g of the enzyme preparationper 5 kg of the formulation and 1 mg of the preparationper 5 g of animal protein.The content of amino acids was determined ona Biotronic 6001 amino acid analyzer (Germany) bydistribution chromatography after acid hydrolysis ofproteins [31].Free amino acids were determined after proteinprecipitation by adding 10% trichloroacetic acid,followed by neutralization with a 10M sodium hydroxidesolution to pH 2.0 and filtration through a Milliporemembrane filter with a pore diameter of 0.22 μm. Then,the filtrate was diluted in a buffer solution (pH 2.2). Toquantify individual amino acids, we compared the peakareas in the aminogram obtained with the WinpeakEppendorf-Biotronic integration system (Germany)by analyzing a standard mixture of amino acids thatcontains 2.5 μmol of each amino acid in 1 ml of thesolution [31].Fatty acids and chemical components responsiblefor the product’s taste and aroma were determined bychromatography-mass spectrometry [21, 31].The components were analyzed on a 7890A gaschromatograph with a 5975C VLMSD mass selectivedetector (Agilent Technologies, USA) using a modifiedFolch method. In particular, a 1 g sample was subjectedto a mixture of 10 mL chloroform and 10 mL methanolin the presence of a 1% KCl solution for 24 h todissolve the lipid components. The extract was filteredthrough paper. After removing the excess solvents byevaporation to dryness, the residue was subjected to acidhydrolysis to obtain methyl esters of fatty acids, whichwere analyzed by gas chromatography.A 0.01 g amount of lipids was treated with 3 mLof a 15% solution of acetyl chloride in methanol at100°C for 2 h. Then, the mixture was neutralizedby KOH (1.25 mL) in СН3ОН to pH 5.0–6.0. A fewminutes after adding 3 mL of a saturated aqueous NaClsolution and 3 mL of hexane, we took for analysis 0.2 μlfrom a clear hexane layer containing methyl estersof fatty acids. Chromatography was performed on a30 m × 0.32 mm × 0.5 mkm HP-Innowax capillarycolumn under the following conditions: the columntemperature in the thermostat increasing from 100°Cto 260°C at a rate of 10°C/min; injector temperature250°C, detector temperature 300°C; hydrogen flow279Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285from the generator at 35 cm3/min; nitrogen flow at20 cm3/min; flow division 1:100; analysis time30 min; injection of 1 μl of the sample. A NIST08 MSLibrary was used to measure the content of isomers,an automatic search and identification program for gaschromatography-mass spectrometry with a probability ofpeaks correlation above 65%.The content of free fatty acids was determined by anacid-base titration of the samples according to the acidnumber. In 2 mg KOH/g of the product, it correspondedto 1% of the mass content of free fatty acids [31].The composition of free carbohydrates was analyzedusing a BioLC chromatographic system, including aGS50 gradient pump, an ED50 electrochemical detector,an EG50 eluent generator with 10mN NaOH, and anLC25 chromatographic thermostat with a CarboPacPA20 column (Dionex, Germany). The content of freecarbohydrates was determined in aqueous extracts of0.01 g of the sample in 100 ml of demineralized HPLCgradewater filtered through a 0.45 μm filter at 25°C.The water retention capacity was determined bya standard method, recording bound moisture underload [31].Our study used casein, tris (hydroxymethyl)aminomethane (tris), phosphoric acid, sodium chloride,sodium hydroxide, potassium hydroxide, and SephadexG-25 (Sigma, USA). As standards of amino acids, weused a solution of mixed individual amino acids in amolar concentration of 2.5 μmol/ml (Supelco, USA):glycine, alanine, valine, leucine, isoleucine, proline,phenylalanine, tyrosine, methionine, cysteine, asparticacid, glutamic acids, lysine, arginine, histidine, serine,and threonine.As standards of fatty acids, we used a solution ofmixed C6–C24 fatty acid methyl esters in methylenechloride with a mass concentration of 10 mg/mL(Supelco, USA): caproic (C6:0), octanoic (C8:0),decanoic (C10:0), decenoic (C10:1), undecanoic (C11:0),dodecanoic (C12:0), tridecanoic (C13:0), tetradecanoic(C14:0), cis-9-tetradecenoic (C14:1), pentadecanoic(C15:0), cis-10-pentadecenoic (C15:1), hexadecanoic(C16:0), cis-9-hexadecenoic (C16:1), heptadecanoic(C17:0), cis-10-heptadecenoic (C17:1), octadecanoic(C18:0), cis-9-octadecenoic (C18:1n9c), trans-9-octadecenoic (С18:1n9t), cis-9,12-octadecadienoic(С18:2n6), cis-6,9,12-оctadecatrienoic (С18:3n6), cis-9,12,15-оctadecatrienoic (С18:3n3), nonadecanoic(С19:0), eicosanoic (С20:0), Cis-9-eicosenoic (С20:1n9),cis-11,14,17-eicosatrienoic (C20:3n3), cis-8,11,14-eicosatrienoic (C20:3n6), cis-11,14,17-eicosatrienoic(C20:3n3), cis-5,8,11,14-eicosatetraenoic (C20:4n6),eicosapentaenoic (C20:5n3), heneicosanoic (C21:0),docosanoic (C22: 0), cis-13-docosenoic (C22:1n9),cis-13,16-docosadienoic (C22:2n6), cis-7,10,13,16,19-docosapentaenoic (C22:5n3), cis-4,7,10,13,16,19-docosahexaenoic (C22:6n3), tricosanoic (C23:0),tetracosanoic (C24:0), and cis-15-tetracosenoic (C24:1).As carbohydrate standards, we used arabinose(Ara, C5H10O5, D-(−)-arabinose ≥ 99%, A3131 Sigma),galactose (Gal, C6H12O6, D-(+)-galactose ≥ 99%, G0750Sigma-Aldrich), glucose (Glc, C6H12O6, D-(+)-glucose≥ 99.5%, G8270 Sigma), xylose (Xyl), mannose (Man,C6H12O6, D-(+)-mannose from wood, ≥ 99% M2069Sigma), fructose (Fru, C6H12O6, D-(−)-fructose ≥ 99%,F0127 Sigma), sucrose (Sug, C12H22O11, α-D-glucose-(1→2)-β-D-fructose, sucrose ≥ 99.5% S9378 Sigma),ribose (C5H10O5, D-(−)-ribose ≥ 99% R7500 Sigma),lactose (Lac, C12H22O11·H2O, β-D-galactose-(1→4)-α-Dglucose,α-Lactose monohydrate reagent grade L3625Sigma-Aldrich), aqueous solutions in a concentration of0.001 mg/mL.RESULTS AND DISCUSSIONAnimal-based products have a protein content of 10to 25% [18, 29]. Fresh raw materials of animal originusually contain from 0.001 to 0.01% of free amino acids,and their content increases with prolonged storage due tointernal enzyme systems. We determined the amino acidcomposition of the model protein and the meat systemprotein before and after introducing Lactobacillusplantarum and Staphylococcus carnosus (Table 1). Wefound that the starter cultures significantly increasedthe total content of free amino acids both in the modelprotein and in the formulation. In the formulation,their content increased to 2.0 ± 0.1%, 2.2 ± 0.1%,and 2.8 ± 0.1% after using Lactobacillus plantarum,Staphylococcus carnosus, and an equimolar mixture ofLactobacillus plantarum and Staphylococcus carnosus,respectively.With the same total concentration of introducedcultures at 4×109 CFU/kg, the mixture of Lactobacillusplantarum and Staphylococcus carnosus increased therate of protein hydrolysis to free amino acids by 30–40%(P > 0.96), compared to their separate action.To determine the treatment time, we observedchanges in the release of free amino acids and thecorrelating values of water retention (Fig. 1). We foundFigure 1 Content of free amino acids (curves 1, 4) and waterretention (curves 2, 3) vs. treatment time with Lactobacillusplantarum and Staphylococcus carnosus (1) and withoutthem (4)Amino acids, g/100 gTime, wk.280Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285that the optimal treatment time was three weeks. Thistime ensured optimal quality parameters of the product,including water retention (Fig. 1).According to Fig. 1, a joint use of the bacterialcultures ensured the maximum concentration of freeamino acids in two weeks. In addition, the waterretention capacity of the food system – an importanttechnological indicator of product quality – was almosttwice as high as when the process lasted a monthwithout using bacterial cultures.The proteolytic activity with respect to the modeland food system proteins showed a synergistic effect ofL. plantarum and S. carnosus on the protein components(Table 2). Their joint use increased the efficiency ofhydrolytic decomposition of the system proteins leadingto a release of free amino acids (Table 1).Table 3 shows the composition of fatty acids in theanimal-based food system and changes in their contentsunder the influence of L. plantarum and S. carnosus.At the initial stages, we found a decrease in thecontents of lower C6–C10 and unsaturated fatty acids,especially essential omega-3 acids (α-оctadecatrienoicC18:3, eicosapentaenoic C20:5, and docosapentaenoicC22:5). However, there was an increase in cis-11,14,17-eicosatrienoic С20:3 acid that is important for propernutrition of mammals. Three weeks of treating thefood system with L. plantarum and S. carnosus led toa decrease in unsaturated fatty acids and an increasein saturated acids by 1–5% (P > 0.95). Similar changesin contents of saturated and unsaturated fatty acids areusually observed for animal-based products subjected tolong-term storage at low temperatures [22, 23].We did not evaluate the direct lipolytic activity ofL. plantarum and S. carnosus in the presence ofsynthetic substrates commonly used for this purpose.However, Table 3 shows that a combined action of thecultures on the system led to a more efficient breakdownof animal fats and a release of free fatty acids, comparedto their individual action. Yet, this effect was notexpressed clearly.Thus, the action of L. plantarum and S. carnosuson the fat components of the food system not onlytransformed the fatty acid composition, but also, to amuch greater extent, increased the amount of free fattyacids.Fig. 2 shows a kinetic curve of changes in thecontent of free fatty acids as a result of treatment withL. plantarum and S. carnosus. Longer treatment timeled to a higher mass fraction of free fatty acids in allcases. We found no differences in the kinetics of freefatty acids formation under individual or joint action ofthe cultures, apparently due to their comparable lipolyticactivity.Table 1 Amino acid composition of model and food system proteins and the content of free amino acids after treatment withLactobacillus plantarum and Staphylococcus carnosusNameof amino acidModelproteinFood system proteins Model protein Food system proteinsg/100g product g/100g protein LP SC LP+SC LP SC LP+SCAsparagine 7.98 1.43 7.24 0.14 0.04 0.17 0.19 0.17 0.16Glutamine 16.4 2.95 15.9 0.81 0.31 0.54 0.87 0.73 0.56Serine 1.59 0.28 1.52 0.01 0.01 0.10 0.03 0.13 0.13Histidine 3.46 0.62 3.38 0.08 0.01 0.08 0.08 0.08 0.14Glycine 2.24 0.40 2.19 0.08 0.01 0.12 0.11 0.13 0.11Threonine 5.91 1.06 5.94 0.04 0.02 0.06 0.03 0.07 0.09Arginine 7.80 1.40 7.77 0.10 0.05 0.13 0.12 0.13 0.12Alanine 3.63 0.65 3.54 0.18 0.04 0.13 0.16 0.15 0.15Tyrosine 3.98 0.71 3.76 0.04 0.01 0.09 0.05 0.07 0.12Cysteine 1.18 0.21 1.15 0.02 0.01 0.04 0.01 0.02 0.04Valine 5.56 1.00 5.48 0.07 0.01 0.08 0.07 0.06 0.09Methionine 3.35 0.60 3.41 0.02 0.02 0.04 0.01 0.02 0.05Phenylalanine 4.55 0.81 4.53 0.01 0.01 0.12 0.02 0.04 0.09Isoleucine 4.93 0.88 4.91 0.01 0.02 0.14 0.02 0.08 0.13Leucine 8.57 1.54 8.49 0.03 0.04 0.12 0.03 0.07 0.13Lysine 10.6 1.91 10.5 0.22 0.17 0.58 0.16 0.17 0.54Proline 3.10 0.55 3.06 0.03 0.03 0.08 0.03 0.06 0.12Tryptophan 1.32 0.23 1.31 0.04 0.01 0.03 0.01 0.02 0.03Ʃ 96.2 17.23 94.1 1.93 0.82 2.65 2.00 2.2 2.8LP – Lactobacillus plantarum; SC – Staphylococcus carnosusTable 2 Proteolytic activity of Lactobacillus plantarumand Staphylococcus carnosus in relation to proteins of animalbasedfood systems, units/mgName LP SC LP+SCModel protein 12 14 17Food system protein 6 4 8LP – Lactobacillus plantarum; SC – Staphylococcus carnosus281Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285The synergistic effect of L. plantarum andS. carnosus on the fat components of the animalbasedfood system did not manifest reliably, since theamounts of free fatty acids in the final products wereapproximately the same.Thus, the action of L. plantarum and S. carnosusresulted in not only the hydrolytic decompositionof fat components, but also in their biochemicaltransformation into ultimate chemical structures. Theincreased content of saturated acids found in our studyshould be considered critically, in light of current trendsin the production of foods with an increased amount ofunsaturated, especially polyunsaturated, fatty acidsof the omega-3 family. This problem should be takeninto account in further development of methods forproducing animal-based foods.Table 3 Changes in the fatty acid composition of the animal-based food system treated with Lactobacillus plantarum,Staphylococcus carnosus and their mixture, % of totalName of fatty acid Initialmixture3 weeks 4 weeks withoutLP SC LP+SC culturesCaproic С 6:0 0.06 0.05 nd – –Octanoic С 8:0 0.17 – – 0.04 –Decanoic С10:0 1.05 1.24 0.48 0.88 0.65Decenoic С 10:1 0.14 0.12 0.08 0.07 0.03Undecanoic C11:0 0.12 0.06 0.06 – 0.02Dodecanoic С12:0 0.75 0.79 1.28 1.14 1.23Tridecanoic C13:0 – – 0.07 – 0.08Tetradecanoic С14:0 2.61 2.18 2.16 2.2 2.34Cis-9-tetradecenoic С 14:1 0.52 0.21 0.18 0.16 0.15Pentadecanoic C15:0 – – 0.12 – 0.12Cis-10-pentadecenoic C15:1 0.29 0.22 0.17 0.16 0.14Hexadecanoic С16:0 19.3 21. 22.8 22.6 23.1Cis-9-hexadecenoic С16:1 4.23 2.24 2.55 2.45 3.18Heptadecanoic С17:0 0.51 – 0.16 0.15 0.33Cis-10-heptadecenoic С17:1 0.18 0.14 0.1 0.12 0.24Octadecanoic С18:0 21.6 24.1 22.4 23.9 23.6Cis-9-octadecenoic С18:1n9c 18.8 19.8 19.2 19.1 18.7Trans-9-octadecenoic С18:1n9t – – 0.01 – 0.02Cis-9,12-octadecadienoic С18:2n6 4.56 3.62 4.23 3.56 3.88Cis-6,9,12-оctadecatrienoic С18:3n6 3.44 3.02 3.17 2.34 2.51Cis-9,12,15-оctadecatrienoic С18:3n3 0.55 0.44 0.61 0.23 0.43Nonadecanoic С19:0 0.07 0.16 0.41 0.28 0.25Eicosanoic С20:0 0.35 0.48 0.49 0.61 0.56Cis-9-eicosenoic С20:1n9 0.45 0.43 0.47 0.45 0.38Cis-11,14-eicosadienoic С20:2n6 3.0 4.45 4.13 4.65 3.62Cis-8,11,14-eicosatrienoic С20:3n6 2.05 3.0 3.23 3.18 3.17Cis-11,14,17-eicosatrienoic С20:3n3 0.41 0.5 0.38 0.44 0.39Cis-5, 8, 11, 14-eicosatetraenoic С20:4n6 0.45 – 0.32 0.11 0.24Cis-5, 8,11,14,17-eicosapentaenoic С20:5n3 0.06 0.02 0.12 0.13 0.07Heneicosanoic C21:0 0.11 0.11 0.06 – 0.15Docosanoic С22:0 0.12 – 0.13 0.12 0.16Cis-13-docosenoic С22:1n9 0.11 0.25 0.2 0.11 0.11Cis-13,16-docosadienoic C22:2 n6 0.46 0.19 0.11 – –Cis-7,10,13,16,19-docosapentaenoic С22:5n3 0.05 0.03 – 0.04 0.01Cis-4,7,10,13,16,19-docosahexaenoic С22:6n3 0.04 0.02 – – 0.03Tricosanoic С23:0 0.1 0.2 0.16 0.15 0.15Tetracosanoic C24:0 0.21 – 0.12 – 0.18Cis-15-tetracosenoic С24:1 – 0.23 0.06 – –Unidentified fatty acids 13.1 10.7 9.8 10.6 9.7Mass fraction of free fatty acids 0.01 0.2 0.2 0.3 0.3nd – not detected282Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285Table 4 shows the quantitative identification offree carbohydrates in the food system treated withL. plantarum and S. carnosus. As we can see, thecontent of some sugars (galactose, glucose, fructose)decreased, while the content of others increased.It appears that the decrease was caused by theconsumption of those sugars by the cultures themselves,whereas the increase was associated with proteolyticand carbohydrolase activity, leading to the breakdownof animal polysaccharides. The mass fraction of suchpolysaccharides in animal raw materials is 2–3%,but their decomposition can lead to the formation of0.1–100 mg% free carbohydrates [18, 23].According to Table 4, free monosaccharides formedmost intensively under the joint action of L. plantarumand S. carnosus. It manifested through changes inthe content of galactose, glucose, xylose, and riboseand through a higher rate of disaccharides (lactoseand sucrose) formation in the food system. In fact, theamount of free lactose was almost twice as high as whenthe cultures were used individually. As a result, theproduct acquired a sweetish taste. Thus, L. plantarumand S. carnosus produced a synergistic effect on thechanges in carbohydrate components of the animalbasedfood system.Further, treating food systems with microculturestotally changes the chemical composition of organicsubstances in raw materials and intermediates or thosesubstances formed as a result. Table 5 shows changesin some minor components of the food system in thepresence of L. plantarum and S. carnosus. The massspectrometric analysis made it possible to identify over250 organic compounds which could be consideredas a result of biochemical effects that microorganismshad on protein, lipid, and carbohydrate components ofthe food system. A large amount of those compoundswere derivatives of fatty acids. Table 5 lists the mainsubstances identified, whose content exceeded 0.001%.As can be seen in Table 5, the joint use ofL. plantarum and S. carnosus resulted in morepronounced changes in almost all compounds, comparedto their individual action. To some extent, this resultindicated a synergistic mechanism of action of bothcultures used to treat animal raw materials.Given that all identified substances can affect thetaste and aroma of final products, varying the use ofstarter cultures – both individual and joint – can makeit possible to obtain products with a wide range ofconsumer properties [21].Finally, the biochemical transformations ofcholesterol require our special attention (Table 5). Thissubstance is a significant component of food systemsbased on animal raw materials. Its high content inproducts is considered as an unfavorable factor leadingto the development of atherosclerosis. In our case,the combined action of the cultures led to a moreconsiderable degradation of cholesterol, which is animportant advantage of using these cultures together.CONCLUSIONThus, the joint use of starter cultures, Lactobacillusplantarum and Staphylococcus carnosus, to treatanimal-based food systems not only increased the yieldof the product, but also had a synergistic effect on theprotein, lipid, and carbohydrate components of thesystem. This may allow us to change the componentcomposition of the system and form the desiredcharacteristics of the food product.Figure 2 Changes in the acid number of the animal-based foodsystem caused by treatment with Lactobacillus plantarum andStaphylococcus carnosus (1), Staphylococcus carnosus (2) andwithout starter cultures (3)Table 4 Changes in free carbohydrate contents in the animal-based food system caused by Lactobacillus plantarum,Staphylococcus carnosus and their mixture, % (g/100 g of sample weight)Name Initial mixture LP LP+SC SC Without starter culturesarabinose 0.016 0.13 0.33 0.16 0.23galactose 1.85 0.0025 0.004 0.0018 0.0015glucose 0.03 0.002 0.003 0.002 0.001xylose + mannose 0.03 0.008 0.05 0.022 0.028fructose + sucrose 0.08 0.006 0.13 0.095 0.053ribose 0.15 0.095 0.19 0.11 0.12lactose 0 0.08 0.18 0.085 0.12LP – Lactobacillus plantarum; SC – Staphylococcus carnosus0.000.200.400 1 2 3 4Acid number, mg KOH/gTime, wk.1 2 3283Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285Table 5 Chemical components in products with Lactobacillus plantarum and Staphylococcus carnosus (n = 6, P = 0.95)Name CAS No. Relative intensity ofmass spectrum mainsignals, unitsProbability of massspectrometric peakidentification fromthe mass spectralibrary, %Rawmaterial,mg/kgFinal product, mg/kg Time,LP SC LP+SC minutes2-phenyl-4-quinolinol 001144-20-3 221(999), 193(44),220(183), 222(171),165(134)66 nd nd 0.003 0.008 4.1232,5-diphenyl-oxazole 000092-71-7 221(999), 165(617),166(388), 892(386),77(351)70 nd nd 0.003 0.002 4.174Cyclobarbital 000052-31-3 207(999), 141(195),81(189), 67(132),79(122)66 0.002 0.003 0.009 0.013 4.237Nonanal dimethyl acetal 018824-63-0 75(999), 157(97),41(88), 69(86),43(83)78 nd 0.001 0.012 0.013 4.3468H-dinaphtho[2,3-b:2’,3’-g]carbazole003557-50-4 367(999), 368(243),366(168), 183(106),184(98)72 0.001 0.001 0.004 0.01 6.603Decanoic acid, methylester **000110-42-9 74(999), 87(585),55(249), 43(205),143(198)96 0.002 0.004 nd 0.006 8.9337-methoxy-9-(3-methyl-2-butenyl)-furo[2,3-b]quinolin-4(9H)-one018904-40-0 215(999), 283(222),216(133), 284(42),172(37)74* 0.002 0.001 0.003 0.011 10.271Ethyl-6-amino-4-[pchloroanilino]-5-nitro-2-pyridincarbamate021271-60-3 351(999), 43(432),353(338), 352(297),270(208)88 0.003 0.006 0.003 0.005 10.8891-hexadecenyl methylester015519-14-9 71(999), 41(330),82(270), 43(170),96(150)96 nd 0.005 0.423 0.579 14.0071,1-dimethoxy-9-octadecene015677-71-1 31(999), 71(850),32(730), 29(520),41(430)91 nd 0.046 0.061 0.067 15.112Methyl-1-octadecenylether026537-06-4 71(999), 82(370),41(300), 43(210),68(190)93 0.009 nd 0.017 0.169 15.2522-methyl-1H-indole 000095-20-5 130(999), 131(657),77(131), 103(110),51(83)63 0.056 0.108 0.106 0.680 16.970cis-11-hexadecenal 053939-28-9 55(999), 41(554),69(436), 67(392),81(376)90 0.03 0.027 0.037 0.082 18.298Cholesterol 000057-88-5 43(999), 55(886),57(744), 105(686),86(681)98 0.331 0.097 0.145 0.065 22.854nd – not detected* – not detected at less than 0.001 mg/kg** – compounds identified as methyl esters by the methodLP – Lactobacillus plantarum; SC – Staphylococcus carnosusCONTRIBUTIONA.N. Ivankin led the project; he set the researchproblem and the objects of study and decided on themethods. A.N. Verevkin conducted experimentalwork with the strains of cultures. A.S. Efremovdeveloped formulations and determined theirphysicochemical parameters. N.L. Vostrikova identifiedand experimentally confirmed the combined effectof the cultures on the protein components of the foodsystem. A.V. Kulikovskii identified and experimentallyconfirmed the microcultures’ effect on the lipidcomponents, as well as established, through massspectrometry, their synergistic action on the mainchemical components of the food system. M.I. Baburina284Ivankin A.N. et al. Foods and Raw Materials, 2020, vol. 8, no. 2, pp. 277–285identified and experimentally confirmed the combinedeffect of the cultures on the carbohydrate components ofthe food system.CONFLICTS OF INTERESTThe authors declare that there is no conflict ofinterests.