Synergetic effects of whey protein isolate and naringin on physical and oxidative stability of oil-in-water emulsions

Application of soy protein isolate-naringenin complexes as fat replacers in low-fat cream: Based on protein conformational changes, aggregation states and interfacial adsorption behavior

In this study, changes in the structural and functional properties of soybean protein isolate (SPI)-naringenin (NG) complexes under different amounts of naringenin treatments were explored, elucidating the effect of the complexes as fat replacers at the 15 % substitution level on the properties of low-fat cream. Finally, the correlation between the structure and function of the complex and the properties of low-fat cream was further analyzed. The addition of NG promotes the increase of SPI aggregation and particle size, and reduces the interfacial tension of the complex. Meanwhile, at the mass ratio of 48:3, NG and SPI formed a dendritic network structure suitable for stabilizing cream. The fat properties of cream indicate that low-fat creams stabilized by appropriate proportions of SPI-NG complexes displayed small and dense fat crystal network structures. In addition, low-fat cream stabilized by the SPI-NG complexes have improved whipping time, overrun, firmness, storage stability and rheological properties compared to natural SPI. It is worth noting that the overall quality of the cream stabilized by the SPI-NG complex with a mass ratio of 48:3 was almost close to that of full-fat cream. Therefore, this study promotes the potential applications of protein-polyphenol complexes as fat replacers in the food industry.

Thermal stability, antioxidant activity and bioavailability of pea protein-naringin Pickering emulsion for enhanced delivery applications

After successfully addressing to mitigate bitterness of naringin through construction Pickering emulsion using pea protein (PP) and naringin (NG) in our previous study, we now probed thermal stability, antioxidant efficacy, and bioavailability. FTIR analysis and UV-vis spectroscopy indicated predominant interactions between PP and NG were hydrogen and hydrophobic bonds. TGA and DSC analyses demonstrated that PP-NG complexes exhibited superior heat-resistance compared to pure PP and NG. Thermal stability assessments indicated a significant retention of NG in the PP-NG Pickering emulsion than the control NG across varied temperatures (4 °C, 25 °C, 37 °C, and 65 °C). Moreover, the antioxidant activity of PP-NG emulsion was dependent on the concentration of NG, as evidenced by DPPH and ABTS free radicals scavenging abilities, ferric reducing power, and lipid peroxidation resistance. Additionally, PP-NG Pickering emulsion exhibited substantially high bioavailability (92.01 ± 3.91%). These results suggest a promising avenue for the application of NG with improved characteristics.

Ultrasound modification on milk fat globule membrane and soy lecithin to improve the physicochemical properties, microstructure and stability of mimicking human milk fat emulsions

Starting from the consideration of the structure of human milk fat globule (MFG), this study aimed to investigate the effects of ultrasonic treatment on milk fat globule membrane (MFGM) and soy lecithin (SL) complexes and their role in mimicking human MFG emulsions. Ultrasonic power significantly affected the structure of the MFGM-SL complex, further promoting the unfolding of the molecular structure of the protein, and then increased solubility and surface hydrophobicity. Furthermore, the microstructure of mimicking MFG emulsions without sonication was unevenly distributed, and the average droplet diameter was large. After ultrasonic treatment, the droplets of the emulsion were more uniformly dispersed, the particle size was smaller, and the emulsification properties and stability were improved to varying degrees. Especially when the ultrasonic power was 300 W, the mimicking MFG emulsion had the highest encapsulation rate and emulsion activity index and emulsion stability index were increased by 60.88 % and 117.74 %, respectively. From the microstructure, it was observed that the spherical droplets of the mimicking MFG emulsion after appropriate ultrasonic treatment remain well separated without obvious flocculation. This study can provide a reference for the screening of milk fat globules mimicking membrane materials and the further utilization and development of ultrasound in infant formula.

Simultaneous ultrasound and microwave application in myosin-chlorogenic acid conjugation: Unlocking enhanced emulsion stability

This study investigated the grafting chlorogenic acid (CA) onto myosin, utilizing various techniques including conventional method, ultrasound, microwave, and combination of ultrasound and microwave (UM). The grafting efficiency was as follows: conventional method < microwave < ultrasound < UM. The UM technique manifested the highest CA-binding capacity (80.26 μmol/g myosin) through covalent bonding, and a much shorter time was required for conjugation than conventional method. The conjugation of polyphenol significantly increased the solubility of myosin with reduced aggregation behavior, which was accompanied by structural alterations from ordered structures (α-helix and β-sheet) to disordered forms. The emulsion stabilized by UM-myosin-CA conjugate exhibited the most homogeneous microstructure with favorable creaming stability. Moreover, the resulting emulsion presented strong oxidation resistance and storage stability. These results illustrate the promising potential of employing CA-grafted myosin, especially when processed using the UM technique, in the development of highly efficient emulsifiers.

Chemical characterization-function relationship of pectins from persimmon fruit within different ripeness

This study investigated the structural and functional characteristics of two different molecular weight persimmon pectin extracted from unripe persimmon (PP-1) and ripe persimmon (PP-2). The molecular weight was determined as 117.8 kDa and 61.3 kDa for PP-1 and PP-2, which consisting of glucose, rhamnose, mannose, galactose, and xylose. AFM results indicated PP-1 with many linear chains, and short chains in while short chains, branching points, and heterogeneous clumps were found in PP-2.Emulsion characterization and storage stability experiments revealed that PP-1 with more stable emulsifying properties than PP-2 and commercial citrus pectin. In vitro fermentation of PP-1 and PP-2 by gut microbiota indicated that PP-1 and PP-2 groups were higher than inulin group in total SCFAs production after 48 h of fermentation. This study provided useful information for high value utilization of persimmon pectin.

Microfluidization of soybean protein isolate-tannic acid complex stabilized emulsions: Characterization of emulsion properties, stability and in vitro digestion properties

Emulsion stability and sustained-release can be improved with a non-covalent complexing of a soybean protein isolate (SPI) with -tannic acid (TA) and dynamic high-pressure microfluidization (DHPM). The microstructure, physicochemical properties, and interfacial properties were investigated. The properties of the DHPM-treated emulsions were improved significantly, with the 120 MPa DHPM-treated SPI-TA emulsion (SPI-TA 120) having the best microstructure. The highest interface protein content, viscosity and viscoelasticity at 120 MPa of pressure facilitated the stability of the emulsion. The oxidation kinetics of emulsions was established. It was demonstrated that the oxidation stability of SPI-TA 120 was higher than SPI and SPI-TA emulsions without DHPM treatment. In addition, DHPM-treated SPI-TA emulsions showed the most positive effect on the slow release of curcumin compared to the control group. The formation of non-covalent protein complexes with polyphenols and DHPM treatment effectively increases the stability of emulsions.

Analysis of non-covalent interaction between β-lactoglobulin and hyaluronic acid under ultrasound-assisted treatment: Conformational structures and interfacial properties

Hyaluronic acid (HA) used as a food ingredient is gaining acceptance and popularity. However, the studies available for the effect of HA concentrations on the properties of β-lactoglobulin (β-LG) were limited. In this study, we investigated that the molecular characterization and functional properties of the complex formed by the non-covalent binding of β-LG and HA, as well as the ultrasound-assisted treatment at acidic pH. The optimal pH and ratio of β-LG/HA were set as 7 and 4:1, respectively. The fluorescence spectroscopy, circular dichroism spectroscopy, and molecular docking results revealed that the addition of HA and ultrasound induced a decrease in random coil and α-helix and an increase in β-sheet contents in β-LG. By the complexation with HA, the thermal stability, freezing stability, and antioxidant properties of β-LG were all improved under ultrasound treatment. The results of the present study can be useful for the modulation of HA based biopolymer complexes and the exploitation as encapsulating or structuring agents in food industry.

Curcumin-loaded oil body emulsions prepared by an ultrasonic and pH-driven method: Fundamental properties, stability, and digestion characteristics

In this study, oil bodies (OBs) loaded with curcumin (Cur) were successfully prepared via an ultrasonic and pH-driven method. Ultrasonic treatment significantly improved the encapsulation efficiency (EE) and loading capacity (LC) of Cur, producing OB particles with small size, uniform distribution, and high ζ-potential absolute values. When the ultrasonic power was 200 W, the EE, LC, and ζ-potential absolute value were the greatest (88.27 %, 0.044 %, and -25.71 mV, respectively), and the OBs possessed the highest yellowness, representing the best treatment result. The confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (cryo-SEM) results was also intuitionally shown that. Moreover, circular dichroism (CD) proved that ultrasonic treatment could unfold the surface protein structure, further enhancing the stability. Therefore, the cream index (CI), peroxide value (POV), and thiobarbituric acid reactive substances (TBARS) were the lowest when the ultrasonic power was 200 W. In this case, the Cur loaded in OBs was well protected against hostile conditions, evidenced by the highest Cur retention rate and the lowest degradation rate constant. Finally, the in vitro gastrointestinal digestion simulation results showed that the ultrasonic treatment effectively increased the release of FFA, bioaccessibility, and stability of Cur, especially when the ultrasonic power was 200 W. This research offers a new OB-based delivery system to stabilize, deliver, and protect Cur for food processing.

Ultrasonic treatment of rice bran protein-tannic acid stabilized oil-in-water emulsions: Focus on microstructure, rheological properties and emulsion stability

Rice bran protein (RBP)-tannic acid (TA) complex was prepared and the RBP-TA emulsions were subjected to ultrasonic treatment with different powers. Ultrasonic treatment has a positive effect on improving the properties of RBP-TA emulsion. This study investigated the influence of different ultrasonic power levels on the physicochemical properties, microstructure, rheological properties, and stability of emulsions containing RBP-TA. Under the ultrasonic treatment of 400 W, the particle size, zeta potential, and adsorbed protein content of the RBP-TA emulsion were 146.86 nm, -20.7 eV, and 61.91%, respectively. At this time, the emulsion had the best emulsifying properties, apparent viscosity, energy storage modulus and loss modulus. In addition, the POV and TBARS values of RBP-TA emulsions were 6.12 and 7.60 mmol/kg, respectively. The thermal, salt ion, pH and oxidative stability of the emulsions were investigated, and it was shown that ultrasonic treatment was effective in improving the stability of RBP-TA emulsions.

Molecular mechanisms affecting the stability of high internal phase emulsions of zein-soy isoflavone complexes fabricated with ultrasound-assisted dynamic high-pressure microfluidization

In this study, zein-soy isoflavone complex (ZSI) emulsifiers were fabricated using ultrasound-assisted dynamic high-pressure micro fluidization to stabilise highinternal phase pickering emulsions. Ultrasound-assisted dynamic high-pressure micro-fluidization enhanced surface hydrophobicity, zeta potential, and soy isoflavone binding capacity, while it decreased particle size, especially during ultrasound and subsequent microfluidization. The treated ZSI could produce small droplet clusters and gel-like structures, with excellent viscoelasticity, thixotropy and creaming stability owing to their neutral contact angles. Ultrasound and subsequent micro fluidization treatment of the ZSI complexes were highly effective in preventing droplet flocculation and coalescence after long-term storage or centrifugation due to their higher surface load, thicker multi-layer interfacial structure, and stronger electronic repulsion between the oil droplets. This study provides insights and extends our current knowledge of how non-thermal technology affects the interfacial distribution of plant based particles and the physical stability of emulsions.

Enhancing the stability of oil-in-water emulsions by non-covalent interaction between whey protein isolate and hyaluronic acid

This study aimed to investigate the effect of non-covalent interactions between different concentrations (0.1-1.2 %, w/v) of hyaluronic acid (HA) and 3 % (w/v) whey protein isolate (WPI) on the stability of oil-in-water emulsions. Non-covalent interactions between WPI and HA were detected using Fourier-transform infrared spectroscopy. The addition of HA increased the electrostatic repulsion between molecules and reduced the particle size of WPI. Circular dichroism spectroscopy results indicated that the addition of HA caused an increase in β-sheet content and a decrease in α-helix and random coil content in WPI. Moreover, HA increased the emulsion viscosity and strength of the interfacial network structure. Micrographs obtained using confocal laser scanning microscopy indicated that the emulsion with 0.8 % (w/v) HA exhibited good dispersion and homogeneity after storage for 14 d. Complexation with HA significantly altered the rheological and emulsifying properties of WPI, providing an emulsion with excellent stability under heating treatment, freeze-thawing treatment and centrifugation. The results provide a potential for HA application in emulsified foods.

Effect of high-intensity ultrasonic treatment on the emulsion of hemp seed oil stabilized with hemp seed protein

In this study, hemp seed oil (HSO) emulsions stabilized with hemp seed protein (HPI) were prepared and treated with high intensity ultrasonic (HIU). The effects of different treatment powers (0, 150, 300, 450, 600 W) on the properties, microstructure and stability of emulsions were investigated. HIU-treated emulsions showed improved emulsifying activity index and emulsifying stability index, reduced particle size, and increased absolute values of ζ-potential, with the extreme points of these indices occurring at a treatment power of 450 W. Here, the emulsion showed the best dispersion and the smallest particle size in fluorescence microscopy observation, with the highest adsorbed protein content (30.12%), and the highest tetrahydrocannabinol (THC) retention rate (87.64%). The best thermal and oxidative stability of the emulsions were obtained under HIU treatment with a power of 450 W. The D₄₃ and the peroxide values (POV) values after 30 d storage were the smallest at 985.74 ± 64.89 nm and 4.6 μmol/L, respectively. Therefore, 450 W was optimal HIU power to effectively improve the properties of HPI-stabilized HSO emulsion and promote the application of HSO and its derivatives in food processing production.

Coating of betanin and carvone Co-loaded nanoliposomes with synthesized cationic inulin: A strategy for enhancing the stability and bioavailability

Betanin (BET) and carvone (CAR) as antioxidant and antibacterial compounds were co-loaded in the coated nanoliposomes (NLPs) with cationic inulin to improve their stability and bioavailability. A cationic inulin was successfully synthesized and used for surface coating of the NLPs. The zeta potential, particle size, and PDI values of the coated NLPs were 21.70 ± 7.00 mV, 143.5 ± 15.2 nm, and 0.35 ± 0.03 respectively. The encapsulation efficiency values of the coated NLPs for BE and CAR were 86.1 ± 3.9 and 77.2 ± 5.2 %, respectively. Electron microscopy results showed that the coated NLPs had spherical and core-shell structures. The slowest sustained release profile in the simulated gastrointestinal condition was obtained for the coated NLPs. The physical and oxidative stability of NLPs, as well as the physical stability of loaded compounds were improved by surface coating. In conclusion, the developed nanocarrier is a suitable platform to use all benefits of BET and CAR in the food industry.

Effects of antioxidants, proteins, and their combination on emulsion oxidation

Lipid oxidation largely determines the quality of emulsion systems as well as their final products. Therefore, an increasing number of studies have focused on the control of lipid oxidation, particularly on its mechanism. In this review, we discuss the factors affecting the efficiency of antioxidants in emulsion systems, such as the free radical scavenging ability, specifically emphasizing on the interfacial behavior and the influence of surfactants on the interfacial distribution of antioxidants. To enhance the antioxidant efficiency of antioxidants in emulsion systems, we discussed whether the combination of antioxidants and proteins can improve antioxidant effects. The types, mixing applications, structures, interface behaviors, effects of surfactants on interfacial proteins, and the location of proteins are associated with the antioxidant effects of proteins in emulsion systems. Antioxidants and proteins can be combined in both covalent and non-covalent ways. The fabrication conditions, conjugation methods, interface behaviors, and characterization methods of these two combinations are also discussed. Our review provides useful information to guide better strategies for providing stability and controlling lipid oxidation in emulsions. The main challenges and future trends in controlling lipid oxidation in complex emulsion systems are also discussed.

Encapsulation and delivery of bioactive citrus pomace polyphenols: a review

Citrus pomace consists of the peel, pulp, and membrane tissues remaining after juice expression. Globally, around one million tons of citrus pomace are generated annually, which contains a variety of bioactive constituents that could be used as value-added functional ingredients in foods. However, the polyphenols in citrus pomace are not currently being utilized to their full potential, even though they can be used as nutraceuticals in functional foods and beverages. Citrus phenolics face significant roadblocks to their successful incorporation into these products. In particular, they have poor water solubility, chemical stability, and bioavailability. This review describes the diverse range of colloidal systems that have been developed to encapsulate and deliver citrus phenolics. Examples of the application of these systems for the encapsulation, protection, and delivery of polyphenols from citrus pomace are given. The use of colloidal delivery systems has been shown to improve the stability, dispersibility, and bioaccessibility of encapsulated polyphenols from citrus pomace. The selection of an appropriate delivery system determines the handling, storage, shelf life, encapsulation efficiency, dispersibility, and gastrointestinal fate of the citrus polyphenols. Furthermore, the purity, solubility, and chemical structure of the polyphenols are key factors in delivery system selection.

Fabrication of Oil-in-Water Emulsions with Whey Protein Isolate-Puerarin Composites: Environmental Stability and Interfacial Behavior

Protein-polyphenol interactions influence emulsifying properties in both directions. Puerarin (PUE) is an isoflavone that can promote the formation of heat-set gels with whey protein isolate (WPI) through hydrogen bonding. We examined whether PUE improves the emulsifying properties of WPI and the stabilities of the emulsions. We found that forming composites with PUE improves the emulsifying properties of WPI in a concentration-dependent manner. The optimal concentration is 0.5%, which is the highest PUE concentration that can be solubilized in water. The PUE not only decreased the droplet size of the emulsions, but also increased the surface charge by forming composites with the WPI. A 21 day storage test also showed that the maximum PUE concentration improved the emulsion stability the most. A PUE concentration of 0.5% improved the stability of the WPI emulsions against environmental stress, especially thermal treatment. Surface protein loads indicated more protein was adsorbed to the oil droplets, resulting in less interfacial WPI concentration due to an increase in specific surface areas. The use of PUE also decreased the interfacial tension of WPI at the oil-water interface. To conclude, PUE improves the emulsifying activity, storage, and environmental stability of WPI emulsions. This result might be related to the decreased interfacial tension of WPI-PUE composites.

Potential development of non-synthetic food additives from orange processing by-products—a review

Citrus is the largest fruit crop worldwide. Meanwhile, oranges account for 60 per cent of the total, with their main application in juice production. During orange juice production, only about 50 per cent of the fresh orange weight is transformed into juice, with the remaining 50 per cent comprised of residue (peel, pulp, seeds, orange leaves and whole orange fruits that do not reach the quality requirements). With the resulting tons of orange by-products, there has been an initiative to research possible ways to reutilize and revalorize citrus waste. Orange pomace, the by-product from juicing process, is currently used to extract the essential oils for fragrance and flavor, and a majority of the waste is used as cattle feed; however, these applications do not account for all of the waste or capture all of its potential value. Meanwhile, these by-products are put into landfills at the owner’s expense, and contribute to global warming through carbon emissions. On the other hand, orange by-products still contain many useful nutraceutical components, such as dietary fiber and phytochemicals, which could be utilized for value-added ingredients and new product development. Some research approaches in this area include the production of organic fertilizers and biofuels, or the extraction of essential oils, pectins, and antioxidant compounds. There is little information in the literature and in the food industry in terms of utilizing the orange pomace directly or with some simple treatments. Orange pomace may be used for food product development as a ‘clean-label’, non-synthetic preservative, which rationalizes this review.

Synergistic stabilization of oil in water emulsion with chitin particles and tannic acid

The aim of the present study was to explore the effect of CP and TA on stability of oil in water emulsion stabilized by the two components, so as to fabricate the most efficient chitin based emulsifying agents. It was found that there was synergistic effect for CP and TA in stabilizing emulsion, specifically, the complex of chitin particles (CP) (3 g/L) with tannic acid (TA) (2 g/L) produced the most physically and oxidatively stable oil-in-water emulsion compared with other groups in this study. This is because CP-TA (3/5) complex had the lowest zeta potential, the lowest the oil water interfacial tension, the highest viscosity and the highest content of TA with excellent antioxidant activity. Furthermore, this is because there was intense interaction between CP and TA in CP-TA complex from results of FTIR, XRD and ITC, which then result in the formation of large CP-TA particles.

Tannic acid enhanced the physical and oxidative stability of chitin particles stabilized oil in water emulsion

In this work, the stability of CP-TA complex stabilized emulsion was first characterized. It was found that the peak thickness, Turbiscan Stability Index (TSI) and droplet size of CP-TA complex stabilized emulsion gradually decreased with increasing content of TA, indicating the gradually enhanced physical stability of emulsion, which was attributed to the gradually decreased interfacial tension, zeta potential and increased viscosity of CP-TA complex. Moreover, the oxidative stability of CP-TA complex stabilized emulsion gradually enhanced with increasing of TA content due to the antioxidant activity of TA. XRD and FTIR results suggested that the interaction between CP and TA gradually enhanced with increasing content of TA in CP-TA complex, leading to the formation of larger CP-TA clusters shown in AFM results. In conclusion, the presence of tannic acid (TA) enhanced the physical and oxidative stability of chitin particles-tannic acid (CP-TA) complex stabilized oil in water emulsion.