Natural Emulsifiers Research Articles

Characterization of astaxanthin-loaded Pickering emulsions stabilized by conjugates of pea protein isolate and dextran with different molecular weights.

Pea protein isolate (PPI) is gaining increasing popularity in the food industry. It provides a diverse range of health benefits, such as hypoallergenic and gluten-free characteristics. However, the functional performance of PPI is hindered by its low solubility and poor stability. Therefore, in this article, PPI and dextran (DX) of different molecular weights were grafted to investigate the effects of grafting DX with different molecular weights on the interface properties and antioxidant properties of PPI. Additionally, the stability and digestive properties of the glycated PPI nanoemulsion system were explored. The result showed that the grafting degree of PPI-DX conjugates (PPI-DC) decreased with an increase in the molecular weight of DX. Surface hydrophobicity, antioxidant activity and solubility of PPI-DC were significantly improved after grafting compared with PPI and PPI-DX mixtures (PPI-DM). Astaxanthin-loaded emulsions stabilized by grafted conjugates had smaller droplets and higher astaxanthin encapsulation rate compared to PPI emulsions. In vitro digestion demonstrated that the bioavailability of PPI-DC emulsions was higher than of PPI emulsion. Furthermore, after 24 days of storage, retention rate of astaxanthin-loaded emulsions prepared by conjugates remained above 70%, surpassing that of PPI emulsion. These results indicated that DX grafting can improve the emulsion properties of PPI. In addition, the DX with a molecular weight of 5 kDa showed the most significant improvement. This study contributes to the advancement of natural emulsifiers by modifying PPI through glycation, and furnishes a valuable reference for its utilization in functional foods. © 2024 Society of Chemical Industry.

Formulation and evaluation of herbal makeup primer

The burgeoning interest in natural and sustainable beauty products has driven the development of herbal makeup primers, which combine cosmetic functionality with the benefits of botanical ingredients. This abstract explores the formulation, efficacy, and advantages of herbal makeup primers. Unlike traditional primers that often rely on synthetic chemicals, herbal primers leverage plant-based extracts known for their skin-enhancing properties, such as aloe Vera& Orange oil. These ingredients offer soothing, anti-inflammatory, and antioxidant benefits that can improve skin texture and promote a healthier complexion. The formulation of herbal makeup primers typically includes a blend of herbal extracts, essential oils, and natural emulsifiers. These components work synergistically to create a smooth base for makeup application while also addressing skin concerns such as redness, dryness, and uneven tone. Clinical and consumer studies suggest that herbal primers can enhance makeup longevity and performance, while simultaneously contributing to overall skin health. In summary, herbal makeup primers represent a significant advancement in cosmetics science by integrating the therapeutic benefits of herbal ingredients into everyday beauty routines. Their growing popularity underscores a shift towards more eco-friendly and skin-conscious beauty solutions, aligning with consumer demand for products that offer both cosmetic and therapeutic benefits. Future research and development in this field are likely to expand the range of available formulations and further validate the efficacy of these natural alternatives.

Egg Yolk, a Multifunctional Emulsifier: New Insights on Factors Influencing and Mechanistic Pathways in Egg Yolk Emulsification

Egg yolk is a highly effective natural emulsifier used in various food products. Its emulsifying properties are influenced by food product chemical conditions, and processing methods. Nevertheless, to effectively utilize egg yolk in food products, a more comprehensive understanding of these factors is crucial. This review discusses recent developments regarding how factors like pH, ionic strength, thermal treatments, enzymatic treatments, and novel non-thermal treatments affect egg yolk emulsifying properties. It also explores the underlying mechanisms involved in egg yolk emulsification. Food products involve different ingredients leading to varying pH values and ionic strength, which affect egg yolk protein adsorption and emulsion stability. Processing steps like thermal treatment can damage egg yolk proteins, reducing their emulsifying capabilities and leading to unstable products. Incorporating sugar, salt, and amino acids can enhance egg yolk’s resistance to heat and preserve its ability to form stable emulsions. As an alternative to thermal treatment, non-thermal techniques such as high-pressure processing and high-intensity ultrasound can be employed to preserve egg yolk. Furthermore, forming egg yolk–polysaccharide complexes can enhance egg yolk emulsifying properties. These advancements have facilitated the creation of egg yolk-based products such as high internal phase Pickering emulsions (HIPEs), low-fat mayonnaise, and egg yolk gels. A comprehensive understanding of the emulsifying mechanisms and factors involved in egg yolk will be instrumental in improving food quality and creating novel egg yolk-based products.

Characterization of Novel Exopolysaccharides from Weissella cibaria and Lactococcus lactis Strains and Their Potential Application as Bio-Hydrocolloid Agents in Emulsion Stability

The aim of the present study was the isolation of high exopolysaccharide (EPS) producers, Lactic Acid Bacteria (LAB) strains, from three types of milk: goat, sheep, and camel milk. Among 112 LAB isolates tested for their ability to produce EPS on MRS-sucrose agar, only 11 strains were able to produce EPS and only three higher producers’ strains were identified by 16S rRNA gene sequencing as two strains of Lactococcus lactis subsp. lactis (SP255, SP257) isolated from camel milk and one strain of Weissella cibaria (SP213) isolated from goat milk. The physicochemical characterization of the purified EPSs revealed a significant sugar yield, with concentrations ranging from 2.17 to 2.77 g/L, while the protein content remained relatively low (0.03 g/L). The UV-visible spectrum showed high Ultra Violet (UV) absorption at 240–280 nm and the Fourier-Transform Infrared (FTIR) spectra showed the presence of a large number of functional groups, including hydroxyl (-OH), carbonyl (-C=O), and methyl groups (-CH3). The EPS solubility indicated their hydrophilic properties and the investigation of interfacial properties indicated that these EPSs could be used as natural emulsifiers and stabilizers in both acidic and neutral emulsions. Moreover, a new type of emulsion system was developed by the utilization of EPSs in the formation of multilayer interfaces in oil-in-water (O/W) emulsions stabilized by sodium caseinate (CAS). Thus, the impact of an EPS addition on the particle size distribution and electrical charge has been studied. At pH 3, the studied EPSs adhered to the surfaces of caseinate-coated droplets and the stability of O/W emulsions was improved by adding certain concentrations of EPSs. The minimum concentration required to stabilize multilayer emulsions for EPSs SP255, EPS SP257, and EPS SP213 was 1.5, 1.5, and 1.7 g/L, respectively. These findings reveal a new EPS with significant potential for industrial use, particularly as an emulsion stabilizer.

Influence of resins, asphaltenes and petroleum acid interactions on water/model oil interfacial properties and emulsion stability

The presence of natural lipophilic emulsifiers, such as asphaltenes (A), resin (R) and petroleum acids (PA) in crude oil, plays a crucial role in stabilizing the W/O emulsions. This study primarily focuses on elucidating the influence of their interactions on the interfacial properties of the water/model oil system, as well as its emulsion stability. First, equilibrium interfacial tension (IFT), interfacial dilational modulus (IDM) and phase angle are measured. Then, emulsion stability experiments are performed. Finally, microscopic images of the emulsions were captured to evaluate droplet size and dispersity. Results show that the addition of petroleum acid to both asphaltene-only and resin-only system reduces IFT and dilational modulus, weakening the strength of the interfacial film. The inhibitory effect of petroleum acid on resins’ adsorption at the interface is more pronounced compared to asphaltenes’. A low proportion of resin and petroleum acid (A/R ≥ 5, A/PA ≥ 7) enhances emulsion stability by co-adsorbing with asphaltenes at the oil–water interface. Conversely, a high proportion of resin and petroleum acid leads to a decrease in IDM and emulsion stability. For asphaltene/petroleum acid–water system, when A/PA ≤ 5, the presence of petroleum acid decreases the droplet size but enhances droplet dispersion while decreasing emulsion stability. It can be inferred that the presence of petroleum acids contributes more to the formation rather than stabilization of emulsions. This work deepens insights into the emulsion behavior of natural surfactants, providing theoretical guidance for the formation of stable emulsions underground and efficient demulsification above ground.

Mechanism study on the improvement of egg white emulsifying characteristic by ultrasound synergized citral: Physicochemical properties, molecular flexibility, protein structure

As a natural emulsifier, egg white protein (EWP) has great interfacial characteristics and high security, and has broad development prospects. This study explored the impact of ultrasound synergized citral (CI) treatment on the microstructure, molecular flexibility and emulsifying property of EWP, and predicted the interaction between CI and ovalbumin (the main protein in EWP) through molecular docking. The decrease in free amino content and the growth in molecular weight of EWP suggested that CI and proteins were successfully grafted. The results of physicochemical properties revealed that UCEWP (ultrasound synergized citral-treated EWP) had smaller particle size and larger ζ-potential absolute value, which meant that the stability of UCEWP system was enhanced. From the perspective of interfacial characteristics, UCEWP had lower interfacial tension, which remarkably improved its emulsifying property. The emulsifying activity index (EAI) and emulsifying stability index (ESI) of UCEWP were 1.99 times and 3.19 times higher than that of natural EWP (NEWP). Analysis of Fourier transform infrared spectroscopy (FT-IR) and fluorescence spectroscopy illustrated that the secondary and tertiary structures of UCEWP were more disordered and stretched than those of EWPs. Protein microstructure demonstrated that UCEWP presented loose small particle distribution, and correlation analysis reflected that the improvement of molecular flexibility was positively correlated with the enhancement of emulsifying property. These results elucidated that ultrasound synergized CI treatment is an effective mean to improve the molecular flexibility and emulsifying property of EWP, which provides a valuable reference for further application of EWP.

The instability of pectin-based emulsions in the upper digestive tract investigated based on the molecular structure and interfacial properties of pectin

Pectin is a widely used natural emulsifier that is thought to stabilize emulsions in the upper gastrointestinal tract (GIT). However, changes in the structural characteristics and interfacial properties of pectin during its digestive treatment in the upper GIT and the effects on the stability of pectin-based emulsions are still unclear. This study showed that the stability of pectin-based emulsions steadily decreased in the upper GIT. Reductions in the molecular weight of pectin (from 2.74× 105 to 1.61× 105 g/mol) occurred mainly in the stomach, whereas the degree of esterification (from 61.2 % to 42.1 %) decreased throughout the digestive treatment. The change in the structure of pectin reduced its hydrophobicity in the upper GIT, and led to form a cross-linked network with Ca2+ in small intestine rather than adsorbing to the oil-water interface. The behavior was reflected in the increased interfacial tension and the decreases in the interfacial modulus and thickness of pectin. Our insights into the structural characteristics and interfacial properties of pectin and thus into the mechanism of pectin instability in the upper GIT will contribute to the development of more efficient encapsulation methods and improved targeted delivery for active substances or probiotics using pectin-based emulsions.

Characteristics of ice cream from black soybean sprout juice – red dragon fruit with yolk emulsifier

Black soybean germination into sprouts reportedly improved nutrition digestibility and bioactive compound content. Red dragon fruit (RDF) and egg yolk (EY) can be used as natural and halal colorants and emulsifiers. Black soybean sprout (BSS) juice made non-dairy ice cream with red dragon fruit and egg yolk as an emulsifier. This research aimed to measure the effect of various red dragon fruit and egg yolk concentrations on the characteristics of ice cream made from BSS juice. A completely randomized design was applied to six formulations made using the ratio of RDF : EY of FA (20%: 3%), FB (20%: 4%), FC (20%: 5%), FD (40%: 3%), FE (40%: 4%), and FF (40%: 5%). BSS juice was made using 48 hours of room temperature incubated sprout and water at a 1:4 (b/v) ratio. Filtrate was then mixed with sugar, cornstarch, and salt into a dough, which was then mixed with RDF and EY at various concentrations. Nutritional proximate composition, radical scavenging activity, phenolic content, total anthocyanin content, vitamin C, and sensory acceptance were analyzed. Data was then statistically analyzed using one-way ANOVA, followed by Duncan’s Multiple Range Test. Results showed that higher RDF significantly changed overrun, melting rate, increased moisture content, vitamin C (20.4 – 40.23 mg/100 g), antioxidant activity (34.9 – 62.78 % radical scavenging activity), total phenolics (0.341 – 0.536 mg/g GAE), and total anthocyanin (3.905 – 9.726 mg/kg), and hedonic score, but shorter melting time. The shortest melting time was obtained by ice cream made using 20% RDF and 5% EY, the lower concentration of fruit, and the highest concentration of egg yolk, respectively. The results indicated that BSS juice could be used as the main ingredient to make non-dairy ice cream, with red dragon fruit and egg yolk as natural colorants and emulsifiers, respectively. Keywords: Black soybean sprout, Non-dairy ice cream, Red dragon fruit

Effects of papain hydrolysate of Pseudosciaena crocea roe on the physical and oxidative stability of water-in-oil emulsions

This study investigates the effects of hydrolysates from Pseudosciaena crocea roe on the physical and oxidative stability of oil-in-water emulsions, emphasizing the structure-activity relationship between peptide structure and emulsifying properties. The results showed that, compared to other proteases, hydrolysates prepared with papain (PCRHs) at moderate degrees of hydrolysis (DH 4.68% and 6.8%) exhibited superior emulsifying activity index (EAI) and emulsifying stability index (ESI). PCRHs with DH of 4.68%, 6.8% formed smaller particle sizes (89.8 ± 3.52 nm, 112 ± 2.65 nm) and more stable emulsions. EAI and ESI of PCRHs were significantly negatively correlated with emulsion particle size and significantly positively correlated with surface hydrophobicity, amino acid composition, relative molecular mass, random coil content and total sulfhydryl groups. Additionally, although PCRHs with DH of 4.68% produced smaller and more stable emulsion particles, PCRHs with DH of 6.8% significantly inhibited primary and secondary lipid oxidation products formation. Correlation analysis revealed that emulsions with smaller particle sizes exhibited poorer oxidative stability, and secondary volatile oxidation products better reflected the oxidative stability of emulsions. Therefore, hydrolysates from Pseudosciaena crocea roe protein with moderate hydrolysis, particularly PCRHs with DH of 6.8%, demonstrate potential as natural emulsifiers to maintain the physical and oxidative stability of oil-in-water emulsions.

The influence of asphaltene and resin on the stability of crude oil emulsion and its demulsification mechanism

Currently, the effects of natural emulsifiers such as resin and asphaltene in crude oil on the stabilities of the emulsions as well as the demulsification mechanism of oil–water separation are still not well understood. In this study, the changes in oil–water wetting angle and interfacial tension (IFT) of crude oil emulsions were compared by extracting resin and asphaltene from crude oil to expound the effects of resin and asphaltene on the stabilities of crude oil emulsions. Meanwhile, the mechanism of demulsifier was discussed based on the competitive adsorption test of demulsifier and asphaltene. It was found that asphaltene was the main emulsifier in the process of oil–water emulsification. With the increase of asphaltene contents, the oil–water wetting angle decreased from 72.9° to 37°, the IFT decreased from 27.13 mN/m to 11.23 mN/m, and the emulsion droplet decreased from 10.3 mm to 1 mm. Demulsifier mainly reduced the stability of crude oil emulsion and realized oil–water separation by the replacement of the interface film-forming substances, the reduction of the oil–water interface tension, and the neutralization of interface charges. The results provide useful information for the demulsification and oil removal of oil-bearing wastewater emulsion.

Formulation and Evaluation of Solid Perfume based on Bees Wax

Solid perfume based on beeswax is a unique and natural fragrance product that provides a long-lasting scent while being gentle on the skin. This type of perfume is made from a combination of natural ingredients, including beeswax, carrier oils, and essential oils. The beeswax acts as a natural emulsifier, which helps to blend the other ingredients and create a solid, compact texture. The carrier oils and essential oils provide the fragrance, which is released slowly and subtly throughout the day. Solid perfume based on beeswax is an excellent alternative to traditional liquid perfumes, as it is more portable, easy to apply, and environmentally friendly. It is also a perfect choice for those with sensitive skin, it contains no alcohol or synthetic ingredients that can irritate the skin. To ensure the success of the presented collection, several quality factors have been established, which will be the same for all four perfumes in the collection, as well as the evaluation indexes of these factors. Quality factors have been classified as sensory, with factors such as the applicability of the product to the skin, and physicochemical, establishing the melting point and stability of the product.mm/second, melting point 90°C and pH value 4.

Enzymatically and chemically starch nanoparticles preparation using ultrasonication, precipitation and lyophilization post-treatments: Screening and characterization

Starch nanoparticles (SNPs) have been used in food emulsions as natural stabilizer and emulsifier. SNPs in colloidal form were produced using enzymatically, acidic and alkaline hydrolyses in combination to ultrasonication and precipitation methods. X-Ray diffraction test for produced SNPs indicated that enzymatically and acidic prepared SNPs had amorphous structure while, the resulted SNPs using alkaline hydrolysis had lower relatively crystallinity. Results indicated that, enzymatically prepared SNPs, had minimum particle size (225 ± 10 nm) and polydispersity index (0.472 ± 0.05), and maximum zeta potential (−26.3 ± 1 mV), antioxidant activity (3.36 ± 0.05 %) and specific surface area (1.8 ± 0.1 m2g−1). Transmission electron microscopy revealed that prepared SNPs had spherical shape and enzymatically prepared SNPs had mean particle size of <100 nm. SNPs in powder form were prepared using freeze drying (pressure and temperature of 100 Pa and − 70 °C). Atomic force microscopy results demonstrated that starch granules had smooth surface, with polyhedral shape and particle size ranging 5 to 25 μm, and after hydrolysis, SNPs had particle size in nanometer scale. Emulsion ability test indicated that oil separation time from the prepared emulsions containing 10 % (W/V) starch, and enzymatically, acidic and alkaline prepared SNPs powder were 41, 70, 82 and 101 s, respectively.

Rice protein hydrolysates as natural emulsifiers for an effective microencapsulation of orange essential oil by spray drying

This study aimed to identify the influence of rice protein hydrolysates (RPH) (degree of hydrolysis DH of 2, 6, and 10%) and rice protein isolate (RPI) on the formation and stabilization of the volatile oil droplets and to verify how protein hydrolysate affects the distribution of components on the surface and physicochemical properties of the spray-dried microparticles. In general, RPHs could reduce the interfacial tension (3.78–4.04 mN/m) compared to non-hydrolyzed protein (4.74 mN/m). However, no significant difference was observed between RPH samples. A positive correlation was observed between the interfacial tension and the oil droplet size, in which RPH emulsions showed 8.29–8.66 µm while RPI was 9.06 µm. DH influenced the surface composition of the spray-dried RPH emulsions. RPH10 powder showed a greater presence of protein (3.3%) on the particle surface and consequently exhibited high oil retention (50.0%). In contrast, this sample presented high hygroscopicity attributed to the protein surface. This study provides insights into differences between RPH powders, which can potentially impact the powder functionality and protection of the active compound.

Effects of Exidia yadongensis polysaccharide as emulsifier on the stability, aroma, and antioxidant activities of fat-free stirred mango buffalo yogurt

Because of the poor stability and rheological properties of fat-free stirred yogurt fortified with fruit pulp, new functional polysaccharides as a natural emulsifier, which can increase viscosity in the aqueous phase, may be needed. This study aimed to evaluate the effects of Exidia yadongensis polysaccharide (EYP) as emulsifier on the stability, aroma, and antioxidant activities of mango buffalo yogurt at 4 °C for 25 days. The yogurt with 15 g/L EYP gave a higher content of 215 g/L total solids, 11.3 g/L exopolysaccharides, 0.10 g/L total polyphenols, 630.5 g/L water-holding capacity, and 11.43 g/kg total free amino acids, and maintained better texture, DPPH scavenging activity of 54.05 % and OH scavenging rates of 67.16 %. Moreover, the EYP exhibited the expected ability to weaken postacidification, syneresis, and growth of microorganism, and greatly promote the textural, rheological properties, suspension stability, microstructure, and aroma profiles of stirred mango-flavored buffalo yogurt (p < 0.05). In addition, the addition of 15 g/L EYP can inhibit protein degradation and improve the stability of secondary structure of the protein complex in mango yogurt during 25 days of storage. Therefore, EYP (15 g/L) could be used as natural positive functional factors and emulsifiers in such fat-free stirred yogurt industry.

Comparative Analysis of Imidazole and Urtica dioica Emulsions in the Management of Dermatophytic Infections

This study explores the epidemiological distribution and antifungal efficacy of treatments against common dermatophytic infections, which predominantly include species from the genera Trichophyton, Microsporum, and Epidermophyton. These infections are significant due to their prevalence and the challenge posed by recurrence and resistance. Between January and September 2022, 35 fungal samples were collected from a dermatological clinic and analyzed using various growth media. Our research focused on evaluating the antifungal effectiveness of a synthetic imidazole emulsion (CSI), an antibiotic, and a natural emulsion from Urtica dioica (CSP). Results revealed that CSI and antibiotic treatments were significantly more effective across all tested species compared to CSP, with CSI often showing superior or comparable efficacy to antibiotics. The findings underscore the robust antifungal properties of imidazole derivatives and suggest a potential limitation in the therapeutic utility of U. dioica extracts. The study highlights the need for continued exploration of innovative treatments and the development of effective management strategies for fungal infections, considering the variance in species prevalence and treatment response.

Lactobacillus-isolated exopolysaccharide as emulsifier ensure extended stability of eugenol encapsulation, potent anti-microbial activity, and application on fresh produce

In this study, we employed a novel encapsulation approach to develop a stable eugenol oil-in-water (O/W) emulsion by using Lactobacillus plantarum ATCC 8014 isolated exopolysaccharide (EPS) as a natural emulsifier. The emulsion was optimized and analyzed for physical stability, microstructure, rheology, and chemical behavior using fourier-transform infrared analysis (FTIR). The eugenol emulsion consisting of a 40:60 O/W ratio with 3 % w/v EPS exhibited a desired droplet size of 192 ± 1.89 nm with multimodal size distribution, polydispersity index of 0.362 ± 0.01 and zeta-potential of −32 ± 1.90 mV. Scanning electron microscopy (SEM) revealed porous and granulated structures with profound consistency. EPS maintained its emulsifying activity across processing conditions (−20 to 70 °C, pH 3–9, salinity 1 %–30 %), with stability over 90 days. Both EPS and eugenol synergistically enhanced the antimicrobial activity of emulsion against Listeria monocytogenes B600 and Salmonella Poona 36. The practical application of optimized emulsion was assessed by demonstrating a reduction in microbial load on the lettuce surface. Microbial load was determined by immersion and sprayed treatment methods which resulted in more than 3.0 log reduction. This potential application of lactobacillus–derived EPS as a natural emulsifier for encapsulating bioactive essential oils will enable its future applications for food safety.

Emulsification characteristics and dehydration of shale oil emulsions under high-frequency electric field

In the face of depleting conventional oil and natural gas reserves, the exploitation of shale oil resources increasingly important. However, the high stability of shale oil emulsions presents a significant challenge to its extraction. In this paper, the differences between shale oil and conventional crude oil and the reasons for the stability of shale oil emulsions were explored. In addition, different dehydration technologies for shale oil emulsions were compared and optimum operating parameters were determined through laboratory-scale experiments. The results show that shale oil emulsions contain much smaller droplets (< 2.25 μm) compared with conventional crude oil emulsions. Further, the high wax content of shale oil allows it to form a high-strength interfacial film at the oil-water interface under the combined action of fracturing fluids and natural emulsifiers, making the emulsion highly stable. Demulsification experiments showed that the use of high-frequency alternating current (AC) pulsed electric fields is an effective method for breaking shale oil emulsions. The optimal demulsification parameters were found to be an electric field frequency of 4 kHz, a field strength of 150 kV·m-1, a residence time of 50 min, an operating temperature of 55 °C, and a demulsifier concentration of 100 ppm. Under these conditions, the dehydrated shale oil was able to meet the standards for commercial crude oil.

Effects of Emulsifiers on Physicochemical Properties and Carotenoids Bioaccessibility of Sea Buckthorn Juice.

The need to improve the physicochemical properties of sea buckthorn juice and the bioavailability of carotenoids is a major challenge for the field. The effects of different natural emulsifiers, such as medium-chain triglycerides (MCTs), tea saponins (TSs) and rhamnolipids (Rha), on the physical and chemical indexes of sea buckthorn juice were studied. The particle size of sea buckthorn juice and the carotenoids content were used as indicators for evaluation. The effects of different addition levels of MCT, Rha and TS on the bioavailability of carotenoids in sea buckthorn juice were investigated by simulating human in vitro digestion tests. The results showed that those emulsifiers, MCT, Rha and TS, can significantly reduce the particle size and particle size distribution of sea buckthorn juice, improve the color, increase the soluble solids content, turbidity and physical stability and protect the carotenoids from degradation. When the addition amount of Rha was 1.5%, the total carotenoids content (TCC) of sea buckthorn juice increased by 45.20%; when the addition amount of TS was 1.5%, the total carotenoids content (TCC) of sea buckthorn juice increased by 37.95%. Furthermore, the bioaccessibility of carotenoids was increased from 36.90 ± 2.57% to 54.23 ± 4.17% and 61.51 ± 4.65% through in vitro digestion by Rha and TS addition, respectively. However, the total carotenoids content (TCC) of sea buckthorn juice and bioaccessibility were not significantly different with the addition of MCT. In conclusion, the findings of this study demonstrate the potential of natural emulsifiers, such as MCT, Rha and TS, to significantly enhance the physicochemical properties and bioavailability of carotenoids in sea buckthorn juice, offering promising opportunities for the development of functional beverages with improved nutritional benefits.

Modification of casein with oligosaccharides via the Maillard reaction: As natural emulsifiers

In the present study, different oligosaccharides (fructooligosaccharide (FOS), galactooligosaccharide (GOS), isomaltooligosaccharide (IMO), and xylooligosaccharide (XOS)) were modified on casein (CN) via Maillard reaction. The CN-oligosaccharide conjugates were evaluated for modifications to functional groups, fluorescence intensity, water- and oil-holding properties, emulsion foaming properties, as well as general emulsion properties and stability. The results demonstrated that the covalent combination of CN and oligosaccharides augmented the spatial repulsion and altered the hydrophobic milieu of proteins, which resulted in a diminution in water-holding capacity, an augmentation in oil-holding capacity, and an enhancement in the emulsification properties of proteins. Among them, CN-XOS exhibited the most pronounced changes, with the emulsification activity index and emulsion stability index increasing by approximately 72% and 84.3%, respectively. Furthermore, CN-XOS emulsions have smaller droplet sizes and higher absolute potential values than CN emulsions. Additionally, CN-XOS emulsions demonstrate remarkable stability when ion concentration and pH are varied. These findings indicate that oligosaccharides modified via Maillard reaction can be used as good natural emulsifiers. This provides a theoretical basis for using oligosaccharides to modify proteins and act as natural emulsifiers.

Effect of protein concentration, pH, and ionic strength on the adsorption properties of rice bran protein concentrates at the oil-water interface

Changes in protein concentration (PC), pH, and ionic strength (IS) influenced the physicochemical, structural, and rheological properties of emulsions made with natural emulsifiers. This study used rice bran protein concentrates (RBPC) to create RBPC-stabilized emulsions (RBP-E) and examined their emulsifying function by changing protein concentration, ionic strength, and pH. The results showed that increasing the PC resulted in a decrease in particle size, which caused the creaming rate and viscosity of RBP-E to increase, leading to the depletion flocculation phenomenon. Incorporating PC into the emulsion system improved adsorbed protein performance in particular pH, which positively correlates to the reduction of emulsion capacity in 3 % PC at neutral conditions. The introduction of IS decreased viscosity, enhanced solubility, and increased protein adsorption, thereby improving emulsion stability within a 3 % protein concentration. FTIR analysis revealed that as the pH shifted from 3 to 7, the α-helical structures increased, while β-sheet and β-turn structures reduced compared to untreated protein, decreasing surface hydrophobicity. Incorporating 1 % PC improved RBP-E performance at pH 7 and 0.5 M, while 2 % PC optimized emulsion capacity at 0.25 M and pH 3. Increasing PC from 1 % to 2 % improved emulsion stability and capacity by 35.4 and 34.4 %, respectively, at 0 M, particularly at pH 5. Therefore, the study concludes that IS, pH, and PC affect the adsorption of plant-derived protein at the O/W interface and enhance the emulsification capabilities of RBPC and the stability of RBP-stabilized emulsions. RPB-E can potentially be used in cake batter, ice cream mix, and margarine premix, a sustainable substitute for animal-based proteins.