Food Emulsions Research Articles

Polysaccharide from Thymelaea hirsuta L. leaves: Structural characterization, functional properties and antioxidant evaluation

In this study, we successfully extracted a new polysaccharide from Thymelaea hirsuta L., which we named THP, with a yield of 13.94 % through aqueous extraction. The polysaccharide comprises 46.83 % neutral sugars and 7.08 % uronic acids. This heteropolysaccharide contains glucose, glucuronic acid, rhamnose, arabinose, and galactose with relative molar ratios of 29.68: 25.73: 21.31: 13.47 and 9.8, respectively. Analysis of glycosylation positions via methylation and structural features using Fourier transform infrared (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) spectroscopy revealed that THP has a repeating unit (1 → 3 and 1 → 4)-linked β-d-glucopyranosyl backbone, with the d-glucopyranosyl residue as the branch point at O-6. The scanning electron microscopy (SEM) examination showed ellipsoidal granules with smooth surface. This polysaccharide also has good foaming capacity and emulsion stability, and a water holding capacity of 1.81 g/g. The THP dispersion at 1 % showed shear thinning behavior, demonstrating that it is a promising natural additive in various food formulations. The polysaccharide also demonstrated significant antioxidant properties, with a total antioxidant capacity of 315 mg α-tocopherol equivalents/g and an IC50 value of 8.01 mg/mL using the β-carotene bleaching method, surpassing those of synthetic antioxidants. Additionally, when added at a concentration of 0.13 % to an oil/water emulsion system, THP effectively delayed lipid oxidation during storage at 37 °C. The kinetic study of THP-stabilized oil/water emulsion is anticipated to provide valuable insights for its future applications in food and pharmaceutical emulsions.

Interfacial Rheological Study of β-Casein/Pectin Mixtures at the Air/Water Interface.

Colloidal food products, such as emulsions, foams, gels, and dispersions, are complex systems that need the presence of stabilizing agents to enable their formation and provide stability. Proteins are often used for food foams and emulsions because of their ability to lower interfacial tension and make viscoelastic interfaces. Generally, to improve the resistance against rupture, polysaccharides are used in association with the proteins. Pectin is a complex polysaccharide that can help to stabilize foams or emulsions. This work aims at studying the mechanical resistance of the interface formed by mixtures of β-casein and pectin at high and low methoxylation degrees at the air/water interface using dilatational and shear kinematics. Frequency sweep tests, in the linear region, were performed in shear at different aging times and in dilatational mode, and the rheological data were analyzed. The transient data of the surface tension were analyzed by kinetic models to obtain the characteristic rates of the interfacial phenomena. The kinetic mechanisms of the protein/pectin mixed systems are controlled by protein and show a weak gel behavior for short aging times. The interfaces obtained with both pectins in a mixture with β-casein evolved with time, gelling and showing a solid-like behavior at concentrations of 1 and 10 g/L and after 3.5 h of aging time. The interfacial shear trend obtained suggests a good stabilizing effect of the pectins from citrus with long aging times.

Effect of lemon balm (Melissa officinalis L.) essential oil on some characteristics of oil/water food emulsions

Food emulsions are used on a daily basis by people, therefore it is of great importance to study the factors that can influence their stability. The aim of this work is to track the influence of lemon balm essential oil (Melissa officinalis L.) on the change of some physical and chemical indicators, kinetic (turbidity) and thermodynamic (Gibbs free energy, enthalpy and entropy) parameters, which are related to their stability. 24 food emulsions were developed with oleic type sunflower oil acting as an oil phase in concentrations of 20 and 30%, soybean protein emulsifier in concentrations of 1, 2, and 3% and lemon balm essential oil in concentrations of 0.1, 0.2 and 0.3%. The pH of the emulsions was determined, microscopic photographs were taken to measure the sizes of the colloidal particles, turbidity was observed for 15 days, their absorbance was determined, Gibbs energy, enthalpy and entropy were calculated. The most stable is the emulsion with 30% oil phase, 3% soybean protein emulsifier and 0.3% lemon balm essential oil.

Emulsifying mechanisms of phospholipids in high-pressure homogenization of perfluorocarbon nanoemulsions.

Phospholipids are the most ubiquitous emulsifiers in foods, beverages, pharmaceuticals, and human physiology, but their emulsifying properties are extremely complex. Differential analyses of mechanisms contributing to their functionality are presented in a modular approach. Addition of cholesterol to a natural phospholipid blend disturbs emulsification beyond specific thresholds for size, polydispersity and formation of emulsifying monolayers. Beyond a ratio of lipid concentration to dispersed volume of 1 mM per 1% (v/v) of perfluorocarbon (PFC), phospholipids no longer form monolayers but instead form triple layers that emulsify the PFC. Using synthetic saturated phospholipids, it can be shown that emulsification is most successful for fatty acids closely below their main transition temperature. Phospholipid head groups are more effective for emulsification the more they increase the area per molecule or the zeta potential. Including a comparison with literature results, it can be shown that high molecular weight emulsifiers like proteins are not dependent on the ratio of viscosities η of the dispersed phase to the continuous phase, ηD/ηC. In contrast, smaller molecular weight emulsifiers like phospholipids show a mild increase in effectiveness with rising ηD/ηC, although this increase is not as strong as that observed for low molecular weight detergents. Ruptures of highly resistant emulsifying interfacial layers obviously lead to direct droplet break-up, irrespective of the resistance of a high-viscosity droplet. The lower the break-up resistance of an emulsifier, the more is it governed by the bulk viscosity of the dispersed phase. Our results allow the preparation of a phospholipid-stabilized emulsion with optimized emulsification settings for pharmaceutical applications.

Possible application of green algae as emulsifiers in foods and nutritional supplements

The high protein content (43.4 %) and the ability of dietary fiber in Spirulina (Arthrospira platensis) to retain water or vegetable oil make the alga suitable for use as an emulsifier in colloidal or emulsion systems. This study aimed to investigate the influence of Spirulina (Arthrospira platensis) (4%, 8%, 12%) as emulsifier on the physical and thermodynamic stability of model emulsions by determining parameters such as Gibbs energy, enthalpy, and entropy. Thermodynamic stability was estimated spectrophotometrically, and physical stability was determined by the Kozin method. It was shown that increasing the Spirulina concentration leads to a decrease in Gibbs free energy and an increase in the physical stability of all emulsions (20%, 40%, 60% oil phases) that are finely dispersed and microscopically determined. The highest percentage of retained emulsion (100 %) was at 12 % Spirulina with an oil phase content of 40 % or 60 %. From a rheological point of view, emulsions with Spirulina at 20 % oil phase showed plastic body behavior, and those with 40 % and 60 % oil phase showed pseudo-plastic behavior.

Effect of heat-treated flaxseed lignan macromolecules on the interfacial properties and physicochemical stability of α-linolenic acid-enriched O/W emulsions.

Flaxseed lignan macromolecules (FLMs) are important polyphenols present in flaxseeds with interfacial adsorption behavior. However, FLMs are easily degraded during thermal treatment in emulsions, which further influences their interfacial properties and application. In this work, the interfacial properties of FLMs between oil and water were evaluated using compression isotherms and interfacial tension to investigate the regulation mechanism of FLMs and their heat-treated products on the stability of O/W emulsions. Furthermore, the improvement mechanism of FLM heat-treated products on the physicochemical stability of flaxseed oil emulsions was clarified. Studies showed that thermal degradation occurred on terminal phenolic acids in FLMs when treated under 100 and 150 °C (FLM-100 and FLM-150) without any decrease in antioxidant activity. FLM-100 and FLM-150 improved the physicochemical stability of sunflower lecithin (S90)-stabilized flaxseed oil emulsions and reduced the concentration of hydroperoxides and TBARS by 26.7% and 80% (p < 0.05), respectively, during storage. This was due to the high interfacial anchoring of FLM-100 and FLM-150, which further strengthened the interface of oil droplets and improved the interfacial antioxidant effect of FLMs. This implies that FLM-100 and FLM-150 could act as new efficient antioxidants for application in food emulsions.

Effects of food emulsifiers on gut microbiota

Effects of food emulsifiers on gut microbiota

Исследование композитов для создания стабильной красящей пищевой системы эмульсионного типа

Composites to create a food system of the W/O emulsion type with a maximum yield of coloring substances were determined. Refined deodorized sunflower oil, beet juice and its concentrates with a dry matter content of 12.23; 18.73; 30.12 and 64.61, a mixture of mono-, diglycerides and glycerin were studied. By gas chromatography, the mass fraction of fatty acid in sunflower oil was determined from the sum of saturated, mono- and polyunsaturated fatty acids, including palmitic (6.5%), oleic (20.9%), and linoleic (66.4%). The content of betanin, conformational changes in mono-, di- and polysaccharide components, and the presence of peptide structures were determined by spectrophotometric methods in beet juice and concentrates. Flow curves of composites for the emulsion were studied by rheometric methods, and interfacial tension was studied by the hanging drop method. To check the physical and sensory properties of the emulsion, the selected composites were dispersed: sufficient conditions for the process were set for its duration – 10 minutes at a rotation speed of 6000 rpm. It is shown that, to create a food emulsion W/O with stable color characteristics during storage, beet juice concentrates with a dry matter content of 64.61% and betanin 0.54% can be used as a dispersed phase. The critical concentration of micelle formation of the emulsion is achieved by adding 0.5% surfactant. The phenomenon of syneresis at a storage temperature of 4 ±0.5℃ for 30 days was not detected.

Polysaccharides as food system stabilizers

From the point of view of the modern healthy nutrition concept, dietary fiber (DF) occupies a leading position among functional ingredients. Expanding the range of food products with the help of DF can strengthen public health and human immune response. Insoluble natural polysaccharides (which make up the main group of polysaccharides) serve as an alternative to surfactants as stabilizers for food emulsions. The quality of ready-to-use food products such as ketchups and mayonnaises deteriorates during long-term refrigeration due to changes in physical and chemical properties. The present research aims to justify the use of disaggregated bacterial cellulose (BC) as a food system stabilizer for mayonnaise sauces and tomato ketchups. It is a unique structurizer of food systems due to its properties: high water-retaining and lipid-binding capacity, fibrillar structure, and lack of toxicity, hence the commercial interest in it as a food additive and functional ingredient. Using scanning probe microscopy, the sizes of BC fibrils were determined: length &gt; 10 μm, width 100-150 nm. Physicochemical parameters of mayonnaise sauce and ketchup samples containing BC were analyzed and compared. The impact the amount of BC has on the organoleptic characteristics of ketchup and mayonnaise was determined.

Modulation of Lipid Digestion by Nanoarchitectonics of Complex Interfacial Structures with Tween 80 and Lecithin.

In recent years, there has been a growing interest in regulating lipid digestion through the construction of various interfacial structures. In the present work, a series of complex interfacial structures were designed by combining Tween 80 in the aqueous phase and lecithin in the oil phase at different concentration ratios. The emulsification properties, the roles in regulating lipid digestion, and the interfacial dilatational rheological properties of the composite emulsifying systems were characterized. The results showed that the combination of Tween 80 and lecithin at different ratios could effectively modulate the rate of lipid digestion. The polyoxyethylene chains of Tween 80 formed a network, that provided a spatial obstacle for the adsorption of bile salts and lipases. Thus, Tween 80 significantly delayed the lipid digestion. The introduction of lecithin gradually replaced Tween 80 molecules at the interface, thus providing space for the adsorption of bile salts and lipases. In addition, as the ratio of lecithin concentration to Tween 80 increased, lecithin gradually became the dominant factor in the interfacial properties. As a result, the rate of lipid digestion was accelerated. Therefore, by compounding different ratios of lecithin and Tween 80, a series of emulsions with different lipid digestion rates were obtained. This research provides a basis for rationally designing food emulsions according to specific needs.

Specialized fat-and-oil emulsion food systems for the prevention of hyperlipidemia and obesity

The development of specialized fat-and-oil emulsion food systems for the prevention of hyperlipidemia and obesity is an important task of health concern in the Russian Federation. The aim of the study was to develop specialized fat-and-oil emulsion food systems for the prevention of hyperlipidemia and obesity, the distinctive features of which are the presence of functional ingredients and bioactive compounds that meet modern safety requirements, have a hypolipidemic effect and influence on body weight. Material and methods. As a source of fucoxanthin, an oil extract from the thallom (stratum) of the annual Undaria pinnatifida brown algae was used, obtained by re-extraction with soy oil for 8 hours from a glycerin extract (extractant - 60% glycerin solution, the duration of the process - 8 h). The determination of organoleptic parameters was carried out at a temperature of 20 °C 12 h after manufacture using standard methods. Organoleptic parameters were determined in the following sequence: consistency, appearance, color, smell, taste. Physical and chemical characteristics (mass content of fat, moisture, egg products in terms of dry yolk, acidity in terms of acetic acid, emulsion stability), acid and peroxide values were studied by standard methods. Fatty acid analysis of lipids was performed by gas-liquid chromatography. The fucoxanthin content was determined by spectrophotometric method. Results. The presented formulations of lipid compositions as the fat base of specialized oil-fat emulsion food systems for the prevention of hyperlipidemia and obesity included Schizochytrium sp. microalgae oil in a mass fraction of 3-6% as a source of ω-3 polyunsaturated fatty acids (PUFAs) (eicosapentaenoic and docosahexaenoic acids). An oil extract of U. pinnatifida brown algae in a mass fraction of 48-54% was used as a source of fucoxanthin. The total content of PUFA was significantly high - at least 73%, ω-6 PUFA prevailed (48.0-49.1%). However, the high content of ω-3 PUFA (at least 25%) should be also noted. The ratio of ω-3 to ω-6 PUFA was 1:1.72-1:1.90, which is atypical for individual vegetable oils traditionally used as the fat phase in fat-and-oil emulsion systems. The fucoxanthin content in the presented lipid compositions was 6.4-7.2 mg/100 ml. Edible fat-and-oil emulsion food systems for the prevention of hyperlipidemia and obesity (mayonnaise and mayonnaise sauces) with a given ratio of ω-3:ω-6 PUFA containing eicosopentaenoic and docosahexaenoic acids, as well as fucoxanthin, have been obtained. The extract of U. pinnatifida brown algae, containing fucoxanthin, significantly slowed down the processes of lipid oxidation and hydrolysis, as evidenced by changes in the peroxide and acid values of fat isolated from specialized fat-and-oil emulsion systems for the prevention of hyperlipidemia and obesity. Conclusion. Specialized fat-and-oil emulsion food systems for the prevention of hyperlipidemia and obesity (mayonnaise and mayonnaise sauces with different oil phase content), containing fucoxanthin, having an optimized fatty acid composition, a given ratio of ω-3:ω-6 PUFA, high content of essential PUFA (eicosopentaenoic and docosohexaenoic acids) are safe food products with traditional organoleptic characteristics and specified physical and chemical parameters.

Investigation of vanillin-loaded O/W, W/O, and W/O/W emulsion systems as a proof of concept for sugar reduction strategy: Preparation, characterization, and evaluation

Achieving food sugar reduction based on odor-taste cross-modal interaction requires careful design of food emulsion systems, which are a promising delivery mechanism with controlled flavor release. Hence, we designed the single (O/W, W/O) and W/O/W double emulsions, which distributed the flavor component (vanillin) and sugar substitute (d-allulose) in the oil and aqueous phase, respectively. In this work. we acquired the optimal formulations for three emulsions and characterized the physical properties of each emulsion. Furthermore, we investigated the stability of three emulsions under various environmental stresses and found that high-temperature short-time (HTST) sterilization had no effect on the quality of the three emulsions, but autoclaving, heat treatment, and freeze-thawing all caused structural integrity damage to the emulsions. Additionally, the storage results indicated that 4 °C might be the optimal temperature for all emulsions. According to these results, W/O emulsions possess the best overall stability, which has great potential for applications to meet the current sugar reduction strategy.

Characterization of food emulsions and dispersions based on nonlinear friction dynamics

AbstractMany foods are emulsions or dispersions containing lipids. The friction properties of foods are evaluated because they affect food texture and processability. Here, we evaluated the friction characteristics of 55 liquid or semisolid foods using a sinusoidal motion friction evaluation system to classify them based on friction dynamics. The contact surface was made to resemble a biological surface using agar gel, which exhibited a fractal structure, and the movement of the contact probe mimicked living movement by sinusoidal motion. The change in average friction coefficient (Δμ), static friction coefficient (Δμs) in a round trip, delay time (Δδ), and friction profile depended on the condition and rheological properties. Principal component analysis showed that all the friction parameters of Δμ, Δμs, Δδ, and the appearance ratio of the profile were involved in the principal components, Z1 and Z2 which are composite variables obtained by the contraction of many friction parameters in a principal component analysis. In addition, the foods were classified into three groups by cluster analysis using Z1 and Z2. The condition of the foods, rheological properties, and the presence or absence of lipids was the factors that defined each group.

A Review of the Utilization of Canola Protein as an Emulsifier in the Development of Food Emulsions.

Canola is the second-largest cultivated oilseed crop in the world and produces meal consisting of about 35-40% proteins. Despite this, less than 1% of the global plant-based protein market is taken up by canola protein. The reason behind such underutilization of canola protein and its rapeseed counterpart could be the harsh conditions of the industrial oil extraction process, the dark colour of the meal, the presence of various antinutrients, the variability in the protein composition based on the source, and the different properties of the two major protein components. Although academic research has shown immense potential for the use of canola protein and its rapeseed counterpart in emulsion development and stabilization, there is still a vast knowledge gap in efficiently utilizing canola proteins as an effective emulsifier in the development of various emulsion-based foods and beverages. In this context, this review paper summarizes the last 15 years of research on canola and rapeseed proteins as food emulsifiers. It discusses the protein extraction methods, modifications made to improve emulsification, emulsion composition, preparation protocols, and emulsion stability results. The need for further improvement in the scope of the research and reducing the knowledge gap is also highlighted, which could be useful for the food industry to rationally select canola proteins and optimize the processing parameters to obtain products with desirable attributes.

Oil-water interfacial behavior of zein-soy protein composite nanoparticles in high internal phase Pickering emulsion

We investigated the interfacial properties of zein-soy protein isolate (SPI) composite particles (ZSCPs) at the oil-water (O/W) interface through pH-shift treatment, along with the preparation and stability of high internal phase Pickering emulsions (HIPPEs). Fourier transform infrared spectroscopy (FTIR), three-dimensional fluorescence, and scanning electron microscopy (SEM) revealed hydrogen bonds and hydrophobic interactions within ZSCPs, altering their structure based on mass ratios. Increasing SPI content in ZSCPs decreased particle size, dynamic interfacial tension (γ), and molecular entanglement, promoting diffusion, penetration, and rearrangement processes. Zein particles (ZPs) exhibited fast diffusion and penetration rates due to higher surface hydrophobicity (H0) and lower zeta potential, while rearrangement was hindered. ZSCPs formed viscoelastic films at the O/W interface, strengthened by SPI. Protein films displayed strain softening during extension in the dilatational measurement under relatively large amplitude (>20%). However, during compression at large amplitude, the protein particle with zein to SPI mass ratios of 10:0 and 7:3 interface films showed strain hardening, while 5:5, 3:7 and 0:10 strain softening. HIPPEs stabilized by ZSCPs showed enhanced interface performance, ensuring long-term stability (upto 30 days). These findings offer new prospects for ZSCP applications in food emulsions, while enhancing our understanding of protein particle adsorption at the O/W interface.

Role of the pea protein aggregation state on their interfacial properties

HypothesisPlant protein ingredients from similar sources can vary in functionality not only because of compositional differences, but also because of differences in their structure depending on their processing history. It is essential to understand these distinctions to develop novel food emulsion using plant proteins. It is hypothesized that differing interfacial properties can be attributed to their structures, aggregation, and colloidal states. ExperimentsThe adsorption behavior of a commercial protein isolate, homogenized or non-homogenized, was compared to a mildly extracted isolate to evaluate the effect of aggregation state and structural differences. After characterization of the particle size and protein composition, the interfacial properties were compared. FindingsAtomic force microscopy provided evidence of interfaces packed with protein oligomers regardless of the treatment. Differences in adsorption kinetics and interfacial shear rheology depending on oil polarity suggested different interfacial structures. A polydisperse mixture of protein oligomers resulted in increased rearrangements and protein-protein interactions at the interface. Homogenization of commercial proteins resulted in a lower interfacial tension and less elastic interfaces compared to those of native proteins due to the presence of larger aggregates. This study highlights how the interfacial properties can be related to the protein aggregation state resulting from differences in processing history.

Fabrication of telechelic DNA-bridged food emulsion gel as edible ink for 3D printing

Abstract Objectives Interdroplet interactions affect the properties and textures of emulsions. In this study, we creatively introduced telechelic DNA to link oil droplets directly at molecular scale to further improve the viscoelastic properties of emulsions. Materials and Methods A stable emulsion with 70% oil fraction was prepared by adding 40 mg/mL of whey protein isolate and peach gum polysaccharide complex (WPI–PGP complex). The addition of telechelic DNA (0.125–0.375 μmol/L) made the emulsion change from a cream-like state to a self-supporting gel. Results Rheological experiments confirmed that the telechelic DNA could improve the yield stress, storage modulus/loss modulus (Gʹ/Gʹʹ) and apparent viscosity of the emulsion gel in a concentration-dependent manner (0–0.375 μmol/L). Inverted fluorescence images clearly showed the interdroplet network of the emulsion gel linked by telechelic DNA. For 3D printing, the emulsion gel with a higher concentration (0.375 μmol/L) of telechelic DNA displayed better surface quality and dimensional resolution, indicating improved printability. Conclusion This study successfully designed a novel telechelic DNA-bridged emulsion gel, which showed great potential as edible ink for 3D printing.

Properties of Heat-Assisted pH Shifting and Compounded Chitosan from Insoluble Rice Peptide Precipitate and Its Application in the Curcumin-Loaded Pickering Emulsions.

Curcumin exhibits antioxidant and antitumor properties, but its poor chemical stability limits its application. Insoluble peptide precipitates formed by proteolysis of rice glutelin are usually discarded, resulting in resource waste. The coupled treatment of heat-assisted pH shifting and compounded chitosan (CS) was used to fabricate rice peptide aggregate-chitosan complexes (RPA-CS). The structure, interfacial behavior, emulsion properties, and digestibility of curcumin-loaded RPA-CS Pickering emulsions were investigated. Increasing the CS concentration led to lower interfacial tension but larger particle size, and the three-phase contact angle of the RPA-CS complexes approached 90°. Quartz crystal microbalance with dissipation (QCM-D) indicated that RPA-CS complexes with 6 g·kg-1 of CS (RPA-CS6) had the highest K1 (0.592 × 106 Hz-1) and K4 (0.487 × 106 Hz-1), suggesting that the softest interfacial layers were formed. The solid-liquid balance of RPA-RPA-CS emulsions was lower than 0.5, declaring that they had more elastic behavior than that of RPA emulsions. RPA-RPA-CS4-and RPA-CS6 emulsions had better storage stability, lower FFA release (79.8% and 76.3%, respectively), and higher curcumin bioaccessibility (65.2% and 68.2%, respectively) than RPA emulsions. This study showed that a low-value insoluble rice peptide precipitate could be used as a valuable emulsifier in foods, which may increase the economics and sustainability of the food supply.

Synthesis and application of a new antibacterial surfactant from apricot kernel oil

Food emulsifier are mostly prepared from a lipophilic lipid tail with a hydrophilic sugar head. In this study, the lipophilic tail was obtained from apricot kernels, which are food waste, and the hydrophilic head was gluconic acid instead of sugar, in order to draw attention to the non-cyclic poly hydroxyl compounds. Thus, oleic acid of apricot kernel was used as the lipophilic moiety of the prepared surfactant. So, apricot kernel was grinned and dried, oil was extracted using soxhlet apparatus, Physical and chemical parameters and fatty acids composition of the extracted oil had been determined. The extracted oil was then hydrolyzed into glycerol and a mixture of free fatty acids. The fatty acids mixture was separated. Then, oleic acid was extracted individually in pure form using supercritical CO2 extractor, it was then confirmed according to its melting point, Gas chromatography–mass spectrometry (GC–MS) after esterification, elemental analysis, Proton nuclear magnetic resonance (H1NMR), and mass spectrometry (MS) to detect the corresponding molecular ion peak. The pure individual oleic acid was converted to hydroxy stearic acid, which was then converted to an amphiphilic compound (surfactant) via esterification reaction with the hydrophilic gluconic acid, and afforded a new surfactant known as 2,3,4,5-tetrahydroxy-6-((9-((-2,3,4,5,6-pentahydroxyhexanoyl) oxy)octadecanoyl) oxy)hexanoic acid or stearyl gluconate for simplification. The structures elucidation of all synthesized compound was established according to elemental analysis and spectral data (Fourier transform infrared IR, 1H NMR, 13C NMR and MS). Moreover, the prepared compound was tasted for its antibacterial activity, and showed good activities against some types of bacteria. The surface-active properties, foamability, foaming stability and emulsion stability of stearyl gluconate were studied and compared with the properties of the well-known surfactant sucrose stearate, and it was clear that, the activity of stearyl gluconate as a surfactant was higher than that of sucrose stearate. Moreover, establishment of safety of this compound was performed using albino rats by acute oral toxicity and kidney and liver functions of these mice. On the other hand, the prepared surfactant was used in the production of low fat—free cholesterol mayonnaise as egg replacer. Texture properties and the sensory evaluation of the prepared mayonnaise showed that the properties were improved by using the new prepared surfactant. Thus, the prepared gluconyl stearate can be used as a safe food additive.

Study on the use of food emulsion and xanthan gum in the composition of yogurt with blended oil

The work is to study the use of food emulsion and xanthan gum in the composition of a yogurt with blended oil. To obtain the yogurt with blended oil, we used skimmed cows milk, skimmed cows milk powder, and a food emulsion consisting of drinking water, blended oil (sunflower and linseed), sodium caseinate, and an emulsifier (a mixture of polyglycerol esters and higher fatty acids). Xanthan gum was used as a stabilizer. The control was yogurt obtained from dairy raw materials. The titrimetric method determined the titrated acidity, which is based on the neutralisation of acids contained in the investigational product with a sodium hydroxide solution in the presence of an indicator. The fatty acid content was determined by chromatographic. Organoleptic quality indicators were assessed by tasting and compared with standard indicators according to DSTU 4418. The number of viable lactic acid bacteria was determined by the method of sowing serial dilutions in agar nutrient media. Samples of the milk-vegetable sour-milk base with 2.0 %, 4.0 % and 6.0 % fat content were obtained by fermenting the milk-vegetable normalized mixture, consisting of a food emulsion, cow's skimmed milk and cow's skimmed milk powder. It had been established that for the minimum value of the titrated acidity of the sour-milk curd of the milk-vegetable sour-milk base of 80 °T to be achieved, the fermentation duration of the milk-vegetable normalized mixture is different compared to the fermentation duration of the milk normalized mixture. Thus, the fermentation duration of the milk normalized mixture and the milk-vegetable normalized mixture with 2.0 % fat content is 8.0 hours and 10.5 hours, respectively, 4.0 % - 8.5 hours and 11.0 hours, respectively, 6.0 % - 8.5 hours and 12.0 hours, respectively. The samples of the obtained milk-vegetable sour-milk base with 2.0 %, 4.0 % and 6.0 % fat content have the number of viable lactic acid bacteria of 1.0 × 107 that corresponds to the standard indicator for the traditional yogurt. For obtaining the yogurt with blended oil of a homogenous, fine, creamy, thick consistency, 0.15-0.20 % xanthan gum should be added to the milk-vegetable sour-milk base with 6.0 % fat content. The content of omega-3 and omega-6 polyunsaturated fatty acids in the yogurt with blended oil with 6.0 % fat content is 1.06 % and 5.44 %, respectively, which is a higher indicator in comparison with the traditional yogurt. The possibility of using a food emulsion as part of a yogurt-type product was established. The resulting yogurt with blended oil is characterized by normative indicators of titrated acidity, the number of viable lactic acid bacteria, organoleptic quality indicators and a high content of polyunsaturated fatty acids. The developed yogurt with blended oil will make it possible to expand the range of the milk-containing sour-milk products and it is recommended for the consumption as the finished product as well as for the use as the semi-finished product.