Investigation into the physicochemical stability and rheological properties of rutin emulsions stabilized by chitosan and lecithin

Enhancing Bovine Embryo Development In Vitro Using Oil-in-Water Nanoemulsions as Specific Carriers for Essential Lipids

Worldwide meat consumption and production have nearly quintupled in the last 60 years. In this context, research and the application of new technologies related to animal reproduction have evolved in an accelerated way. The objective of the present study was to apply nanoemulsions (NEs) as carriers of lipids to feed bovine embryos in culture media and verify their impact on the development of embryos produced in vitro. The NEs were characterized by particle size, polydispersity, size distribution, physical stability, morphology using atomic force microscopy (AFM), surface tension, density, pH, and rheological behavior. The NEs were prepared by the emulsification/evaporation technique. A central composite rotatable design (CCRD) was used to optimize the NE fabrication parameters. The three optimized formulations used in the embryo application showed an emulsion stability index (ESI) between 0.046 and 0.086, which reflects high stability. The mean droplet diameter analyzed by laser diffraction was approximately 70-80 nm, suggesting a possible transit across the embryonic zona pellucida with pores of an average 90 nm in diameter. AFM images clearly confirm the morphology of spherical droplets with a mean droplet diameter of less than 100 nm. The optimized formulations added during the higher embryonic genome activation phase in bovine embryos enhanced early embryonic development.

Study on the structural characteristics and emulsifying properties of chickpea protein isolate-citrus pectin conjugates prepared by Maillard reaction

Chickpea protein isolate (CPI) typically exhibits limited emulsifying properties under various food processing conditions, including pH variations, different salt concentrations, and elevated temperatures, which limits its applications in the food industry. In this study, CPI-citrus pectin (CP) conjugates were prepared through the Maillard reaction to investigate the influence of various CP concentrations on the structural and emulsifying properties of CPI. With the CPI/CP ratio of 1:2, the degree of graft reached 35.54 %, indicating the successful covalent binding between CPI and CP. FT-IR and intrinsic fluorescence spectroscopy analyses revealed alterations in the secondary and tertiary structures of CPI after glycosylation modification. The solubility of CPI increased from 81.39 % to 89.59 % after glycosylation. Moreover, freshly prepared CPI emulsions showed an increase in interfacial protein adsorption (70.33 % to 92.71 %), a reduction in particle size (5.33 μm to 1.49 μm), and a decrease in zeta-potential (-34.9 mV to -52.5 mV). Simultaneously, the long-term stability of the emulsions was assessed by employing a LUMiSizer stability analyzer. Furthermore, emulsions prepared with CPI:CP 1:2 exhibited excellent stability under various environmental stressors. In conclusion, the results of this study demonstrate that the glycosylation is a valuable approach to improve the emulsifying properties of CPI.

Characterization, Stability and Antioxidant Activity of Vanilla Nano-Emulsion and Its Complex Essential Oil

As a natural flavoring agent, vanilla essential oil has a special aroma and flavor, but its volatility and instability limit its value. Therefore, in this study, vanilla essential oil was compounded with cinnamon essential oil to prepare nano-emulsions (composite nano-emulsions called C/VT and C/VM), and the stability of the composite essential oil emulsions was investigated. Transmission electron microscopy (TEM) images showed that the nano-emulsions were spherical in shape and some flocs were observed in C/VM and C/VT. The results showed that the average droplet sizes of C/VM and C/VT increased only by 14.99% and 15.01% after heating at 100 °C for 20 min, and the average droplet sizes were less than 120 nm after 24 days of storage at 25 °C. Possibly due to the presence of reticulated flocs, which have a hindering effect on the movement of individual droplets, the instability indices of C/VM and C/VT were reduced by 34.9% and 39.08%, respectively, in comparison to the instability indices of C/VM and C/VT. In addition, the results of antioxidant experimental studies showed that the presence of composite essential oil flocs had no significant effect on the antioxidant capacity. These results indicate that the improved stability of the composite essential oil nano-emulsions is conducive to broadening the application of vanilla essential oil emulsions.

New Insight into Food-Grade Emulsions: Candelilla Wax-Based Oleogels as an Internal Phase of Novel Vegan Creams

Cream-type emulsions containing candelilla wax-based oleogels (EC) were analyzed for their physicochemical properties compared to palm oil-based creams (EP). The microstructure, rheological behavior, stability, and color of the creams were determined by means of non-invasive and invasive techniques. All the formulations exhibited similar color parameters in CIEL*a*b* space, unimodal-like size distribution of lipid particles, and shear-thinning properties. Oleogel-based formulations were characterized by higher viscosity (consistency index: 172-305 mPa·s, macroscopic viscosity index: 2.19-3.08 × 10-5 nm-2) and elasticity (elasticity index: 1.09-1.45 × 10-3 nm-2), as well as greater resistance to centrifugal force compared to EP. Creams with 3, 4, or 5% wax (EC3-5) showed the lowest polydispersity indexes (PDI: 0.80-0.85) 24 h after production and the lowest instability indexes after environmental temperature changes (heating at 90 °C, or freeze-thaw cycle). EC5 had particularly high microstructural stability. In turn, candelilla wax content ≥ 6% w/w accelerated the destabilization processes of the cream-type emulsions due to disintegration of the interfacial layer by larger lipid crystals. It was found that candelilla wax-based lipids had great potential for use as palm oil substitutes in the development of novel vegan cream analogues.

Impact of Incorporating Free Calcium and Magnesium on the Heat Stability of a Dairy- and Soy-Protein-Containing Model Emulsion

This study investigated the impact of calcium chloride (CaCl2) and magnesium chloride (MgCl2) at varying concentrations on a model milk formulation's physical and chemical properties after thermal treatment. The model milk was subjected to two-stage homogenization and pasteurization before being supplemented with different concentrations of CaCl2 or MgCl2. The findings revealed that elevating the concentration of either calcium or magnesium resulted in the milk emulsion having a higher viscosity and median particle size following heating. CaCl2 had a slightly stronger impact than MgCl2, particularly at higher concentrations. The milk samples also exhibited a reduction in the zeta potential as the ionic strength of the salt solution increased, with the CaCl2-fortified milk displaying a slightly lower negative surface charge than the MgCl2-fortified milk at the same dose. The model milk's viscosity was evaluated after adding various salt concentrations and a temperature ramp from 20 to 80 °C. Notably, the viscosity and particle size changes demonstrated a non-linear relationship with increasing mineral levels, where a significant increase was observed at or above 5.0 mM. An emulsion stability analysis also revealed that the de-stabilization pattern of the high salt concentration sample differed significantly from its low salt concentration counterparts. These findings could serve as a basis for the future development of fortified UHT milk with nutritionally beneficial calcium and magnesium in industrial applications.

Interfacial Rheological and Emulsion Properties of Self-Assembled Cyclodextrin-Oil Inclusion Complexes

To investigate the effect of the molecular size of alkanes and the cavity size of cyclodextrins (CDs) on the formation of interfacial host-guest inclusion complexes, the interfacial tension (IFT) of CD (α-CD, β-CD, γ-CD) solutions against oils (hexadecane, dodecylbenzene) was determined by interfacial dilational rheology measurements. The results show that the "space compatibility" between CDs and oil molecules is crucial for the formation of interface host-guest inclusion complexes. Hexadecane with a smaller molecular size can form host-guest inclusion complexes with small cavities of α-CD and β-CD, dodecylbenzene with a larger molecular size can form interfacial aggregates with the medium-sized cavity of β-CD easily, and the polycyclic aromatic hydrocarbon molecules in kerosene can form inclusion complexes with the large cavity of γ-CD. The formation of interfacial inclusion complexes leads to lower IFT values, higher interfacial dilational modulus, nonlinear IFT responses to the interface area oscillating, and skin-like films at the oil-water interface. What's more, the phase behavior of Pickering emulsions formed by CDs with different oils is explored, and the phenomena in alkane-CD emulsions are in line with the results in dilatation rheology. The interfacial active host-guest structure in the kerosene-γ-CD system improves the stability of the Pickering emulsion, which results in smaller emulsion droplets. This unique space compatibility characteristic is of great significance for the application of CDs in selective host-guest recognition, sensors, enhanced oil recovery, food industries, and local drug delivery.

Pullulan-stabilized Soybean Phospholipids/Cinnamaldehyde emulsion for Flammulina velutipes preservation

Fresh mushrooms (Flammulina velutipes) are very perishable and easily brown; also they undergo postharvest loss of nutritive constituents. In this study, cinnamaldehyde (CA) emulsion was prepared by using soybean phospholipids (SP) as emulsifier and pullulan (Pul) as stabilizer. The effect of emulsion on the quality of mushroom during storage was also studied. The experimental results indicated that the emulsion obtained by adding 6 % pullulan was found to the most uniform and stable, which is beneficial to its application. Emulsion coating maintained the storage quality of Flammulina velutipes. The incorporation of CA emulsion into the coating system showed a positive effect on inhibiting the accumulation of reactive oxygen species, resulting from improving the effectiveness of delaying active free radical scavenging enzymes. The shelf life of mushrooms coated with emulsion was significantly prolonged, which indicates its potential application in food preservation.

Rutin: Family Farming Products' Extraction Sources, Industrial Applications and Current Trends in Biological Activity Protection

In vitro and in vivo studies have demonstrated the bioactivity of rutin, a dietary flavonol naturally found in several plant species. Despite widespread knowledge of its numerous health benefits, such as anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects, industrial use of rutin is still limited due to its low solubility in aqueous media, the characteristic bitter and astringent taste of phenolic compounds and its susceptibility to degradation during processing. To expand its applications and preserve its biological activity, novel encapsulation systems have been developed. This review presents updated research on the extraction sources and methodologies of rutin from fruit and vegetable products commonly found in a regular diet and grown using family farming approaches. Additionally, this review covers quantitative analysis techniques, encapsulation methods utilizing nanoparticles, colloidal and heterodisperse systems, as well as industrial applications of rutin.

Recent developments in improving the emulsifying properties of chitosan

Chitosan is one of the valuable products obtained from crustacean waste. The unique characteristics of chitosan (antimicrobial, antioxidant, anticancer, and anti-inflammatory) have increased its application in various sectors. Besides unique biological properties, chitosan or chitosan-based compounds can stabilize emulsions. Nevertheless, studies have shown that chitosan cannot be used as an efficient stabilizer because of its high hydrophilicity. Hence, this review aims to provide an overview of recent studies dealing with improving the emulsifying properties of chitosan. In general, two different approaches have been reported to improve the emulsifying properties of chitosan. The first approach tries to improve the stabilization property of chitosan by modifying its structure. The second one uses compounds such as polysaccharides, proteins, surfactants, essential oils, and polyphenols with more wettability and emulsifying properties than chitosan's particles in combination with chitosan to create complex particles. The tendency to use chitosan-based particles to stabilize Pickering emulsions has recently increased. For this reason, more studies have been conducted in recent years to improve the stabilizing properties of chitosan-based particles, especially using the electrostatic interaction method. In the electrostatic interaction method, numerous research has been conducted on using proteins and polysaccharides to increase the stabilizing property of chitosan.

Multiscale combined techniques for evaluating emulsion stability: A critical review

Emulsions are multiscale and thermodynamically unstable systems which will undergo various unstable processes over time. The behavior of emulsifier molecules at the oil-water interface and the properties of the interfacial film are very important to the stability of the emulsion. In this paper, we mainly discussed the instability phenomena and mechanisms of emulsions, the effects of interfacial films on the long-term stability of emulsions and summarized a set of systematic multiscale combined methods for studying emulsion stability, including droplet size and distribution, zeta-potential, the continuous phase viscosity, adsorption mass and thickness of the interfacial film, interfacial dilatational rheology, interfacial shear rheology, particle tracking microrheology, visualization technologies of the interfacial film, molecular dynamics simulation and the quantitative evaluation methods of emulsion stability. This review provides the latest research progress and a set of systematic multiscale combined techniques and methods for researchers who are committed to the study of oil-water interface and emulsion stability. In addition, this review has important guiding significances for designing and customizing interfacial films with different properties, so as to obtain emulsion-based delivery systems with varying stability, oil digestibility and bioactive substance utilization.

Determination of the best interaction of inulin with different proteins by using interfacial rheology: the relationship with the emulsion activity and stability in emulsion systems

This study aimed to develop functional emulsions with dietary fibre/proteins and to examine the role of interfacial rheological properties on the emulsion stability. Emulsions with inulin and various animal/vegetable proteins were prepared, and their emulsifying and interfacial rheological properties were appraised for their possible applications in stabilizing oil-in-water emulsions. Interfacial measurements including the frequency, time and strain sweep test were determined depending on the protein differences. The results revealed that the adsorption behaviour of proteins at the two interfaces was quite different. The apparent viscosity (η 50) of the emulsions ranged between 0.006 and 0.037 Pa s. The highest interfacial viscosity (η i) values at low shear rates were determined in the mixture of egg protein-inulin at the oil/water interface. In particular, the interfacial properties of egg protein were not similar to those of other proteins. This study indicated that interfacial rheological properties and emulsifying properties of the proteins were influenced by the presence of inulin which contributes to the existing body of knowledge on the preparation of the prebiotic emulsions with proteins.

Single-cell Raman-activated sorting and cultivation (scRACS-Culture) for assessing and mining in situ phosphate-solubilizing microbes from nature

Due to the challenges in detecting in situ activity and cultivating the not-yet-cultured, functional assessment and mining of living microbes from nature has typically followed a 'culture-first' paradigm. Here, employing phosphate-solubilizing microbes (PSM) as model, we introduce a 'screen-first' strategy that is underpinned by a precisely one-cell-resolution, complete workflow of single-cell Raman-activated Sorting and Cultivation (scRACS-Culture). Directly from domestic sewage, individual cells were screened for in-situ organic-phosphate-solubilizing activity via D2O intake rate, sorted by the function via Raman-activated Gravity-driven Encapsulation (RAGE), and then cultivated from precisely one cell. By scRACS-Culture, pure cultures of strong organic PSM including Comamonas spp., Acinetobacter spp., Enterobacter spp. and Citrobacter spp., were derived, whose phosphate-solubilizing activities in situ are 90-200% higher than in pure culture, underscoring the importance of 'screen-first' strategy. Moreover, employing scRACS-Seq for post-RACS cells that remain uncultured, we discovered a previously unknown, low-abundance, strong organic-PSM of Cutibacterium spp. that employs secretary metallophosphoesterase (MPP), cell-wall-anchored 5'-nucleotidase (encoded by ushA) and periplasmic-membrane located PstSCAB-PhoU transporter system for efficient solubilization and scavenging of extracellular phosphate in sewage. Therefore, scRACS-Culture and scRACS-Seq provide an in situ function-based, 'screen-first' approach for assessing and mining microbes directly from the environment.

Modifying the Stability and Surface Characteristic of Anthocyanin Compounds Incorporated in the Nanoliposome by Chitosan Biopolymer

In this study, a novel approach was investigated to improve the stability of anthocyanin compounds (AC) by encapsulating them in nanoliposomes resulting from rapeseed lecithin alongside chitosan coating. The results indicate that the particle size, electrophoretic mobility, encapsulation efficiency, and membrane fluidity of nanoliposomes containing anthocyanin compounds were 132.41 nm, −3.26 µm·cm/V·S, 42.57%, and 3.41, respectively, which changed into 188.95 nm, +4.80 µm·cm/V·S, 61.15%, and 2.39 after coating with chitosan, respectively. The results also suggest improved physical and chemical stability of nanoliposomes after coating with chitosan. TEM images demonstrate the produced particles were spherical and had a nanoscale, where the existence of a chitosan layer around the nanoparticles was visible. Shear rheological tests illustrate that the flow behavior of nanoliposomes was altered from Newtonian to shear thinning following chitosan incorporation. Further, chitosan diminished the surface area of the hysteresis loop (thixotropic behavior). The oscillatory rheological tests also show the presence of chitosan led to the improved mechanical stability of nanoliposomes. The results of the present study demonstrate that chitosan coating remarkably improved encapsulation efficiency, as well as the physical and mechanical stability of nanoliposomes. Thus, coating AC-nanoliposomes with chitosan is a promising approach for effective loading of AC and enhancing their stability to apply in the pharmaceutic and food industries.

Improved stability of liposome-stabilized emulsions as coencapsulation delivery system for vitamin B2, vitamin E and β-carotene

To realize the co-encapsulation of multiple nutraceuticals with different solubilities, Pickering emulsions stabilized by freshly-prepared liposome suspension stabilized emulsion (Fre-Lip-Sus-E) and hydrated lyophilized liposome stabilized emulsion (Hyd-Lyo-Lip-E) were prepared, in...

Characterization, Bioactivity and Application of Chitosan-Based Nanoparticles in a Food Emulsion Model

In this study, chitosan nanoparticles (CNPs) were prepared by the ionic gelation technique with tripolyphosphate (TPP), and the effect of CNP composition and physicochemical characteristics were evaluated. After the synthesis optimization, CNPs were used as carriers for a fish protein hydrolysate (FPH) with bioactive properties (CNPH). The physicochemical characteristics, antioxidant capacity and antimicrobial, antihypertensive and emulsifier properties of unloaded and loaded CNPs in a food system model were studied. CNPH showed a uniform particle distribution, size ~200 nm, high stability (zeta potential around 30 mV), radical scavenging activity and increased antimicrobial activity against Staphylococcus aureus, Shigella sonnei and Aeromonas hydrophila. Additionally, CNPH showed an angiotensin I-converting enzyme (ACE)-inhibitory activity of 63.6% and, when added to a food emulsion model, this system containing CNPs, with or without FHP, exhibited improved food emulsion stability. Thus, CNPs were able to carry the FPH while maintaining their bioactive properties and can be an alternative to the delivery of bioactive peptides with potential as an emulsion stabilizer for food applications.

Advances in biopolymeric active films incorporated with emulsified lipophilic compounds: a review

The attention towards active films has increased due to consumer demand for high-quality foods without chemical additives. Active biopolymer-based films have shown great potential for active films by impacting food safety, acting as the carriers of various natural antioxidant and antimicrobial compounds, and decreasing environmental pollution from petrol-derived packaging materials. However, there is a wide range of challenges concerning the different characteristics of biopolymers and plasticizers, often hygroscopic/hydrophilic, compared to numerous lipophilic bioactive compounds. Therefore, recent studies have focused on applying oil-in-water emulsion-based systems to enhance the lipophilic bioactive compounds' dispersibility into the film matrix, improving their performance. It is worth emphasizing that resulting complex systems give rise to new challenges such as (i) dispersion technology of the bioactive compounds with minimum adverse effects on its bioactivities, (ii) interactions between different components of the active films, giving rise to new physicochemical properties, and (iii) the change of the diffusion properties of bioactive compounds into the active films, resulting in different release properties. These challenges are profound and critically discussed in this review, as well as the encapsulation techniques employed in preparing emulsions loaded with lipophilic bioactive compounds for the active film development. An outlook of future directions in the research, development, and application of these active films are given.

The attention towards active films has increased due to consumer demand for high-quality foods without chemical additives.

High-intensity ultrasound improves the physical stability of myofibrillar protein emulsion at low ionic strength by destroying and suppressing myosin molecular assembly

The specific molecular behavior of myofibrillar proteins (MPs) in low-salt media limits the development of muscle protein-based emulsions. This study aimed to evaluate the potential of high-intensity ultrasound (HIU; 150, 300, 450, and 600 W) to improve the physical stability of MP emulsion at low ionic strength and decipher the underlying mechanism. According to the physical stability analysis, HIU pretreatment, especially at 450 W power, significantly improved the physical stability of MP emulsions, as evidenced by the reduced particle size, enhanced inter-droplet interactions, and increased uniformity of the droplet size distribution (p < 0.05). The results of interfacial protein composition, Fourier transform infrared spectroscopy analysis, and microscopic morphology observation of the aqueous MP suspension suggested that HIU induced the depolymerization of filamentous myosin polymers and inhibited the subsequent self-assembly behavior. These effects may facilitate protein adsorption and molecular rearrangement at the oil-water interface, forming a complete interfacial layer and, thus, droplet stabilization. Confocal laser scanning microscopy observations further confirmed these results. In conclusion, these findings provide direct evidence for the role of HIU in improving the physical stability of MP emulsions at low ionic strength.

Recent advances in polysaccharides stabilized emulsions for encapsulation and delivery of bioactive food ingredients: A review

Many bioactive food ingredients were encapsulated in different forms to improve their stability and bioavailability. Emulsions have showed excellent properties in encapsulation, controlled release, and targeted delivery of bioactives. Polysaccharides are widely available and have different structures with different advantages including non-toxic, easily digested, biocompatible and can keep stable over a wide range of pH and temperatures. In this review, the most common polysaccharides and polysaccharide based complexes as emulsifiers to stabilize emulsions in recent ten years are described. The close relationships between the types and structures of polysaccharides and their emulsifying capacities are discussed. In addition, the absorption and bioavailability of bioactive food components loaded in polysaccharide stabilized emulsions are summarized. The main goal of the review is to emphasize the important roles of polysaccharides in stabilizing emulsions. Moreover, speculations regarded to some issues for the further exploration and possible onward developments of polysaccharides stabilized emulsions are also discussed.

Environmental fungi and bacteria facilitate lecithin decomposition and the transformation of phosphorus to apatite

Organophosphorus compounds (OP) are stable P source in nature, and can increase eutrophication risk in waterbodies. Lecithin was the most difficult OP to be broken down. In this study, two typical phosphate-solubilizing microorganisms, Aspergillus niger and Acinetobacter sp., were applied to evaluate their ability to decompose both inorganic phosphates and lecithin. A. niger and Acinetobacter sp. could solubilize calcium phosphates by secreting various organic acids, e.g., oxalic and formic acids. The fungus, A. niger, shows significantly higher ability of solubilizing these inorganic phosphates than Acinetobacter sp., primarily due to its secretion of abundant oxalic acid. However, the bacterium, Acinetobacter sp., could secrete more acid phosphatase than A. niger for lecithin decomposition, i.e., 9300 vs. 8500 μmol L-1 h-1. Moreover, after addition of CaCl2, the released P from lecithin was transformed to stable chlorapatite in the medium. To the contrast, Ca cations inclined to form calcium oxalate (rather than stable phosphate mineral) after the incubation of A. niger, as it induced relatively acidic environment after breaking down lecithin. Therefore, this work sheds light on the bright future of applying bacteria and Ca cations in OP pollutant management.

Chitosan-coated different particles in spouted bed and their use in dye continuous adsorption system

In this work, three polymer suspensions were used for coating glass beads (GB), porcelain beads (PB), and polyethylene pellets (PP) in spouted bed. Subsequently, the continuous adsorption assays of the food dye Brilliant Blue FCF in a fixed bed column were performed, which was packed with the covered particles. Also, the static adsorption assays were carried out. The adsorption equilibrium isotherms were fitted by Freundlich, Langmuir, and Temkin models, being that the Temkin model was the most suitable to represent the equilibrium data. The particle coating in the spouted bed showed promising results due to the high efficiency of the process. The PB, GB, and PP obtained coating efficiency values in the range to 92-96% when using the suspension of chitosan and hydroxyethyl cellulose. However, only the polyethylene particles coated with the chitosan suspension maintained its coating efficiency (95%). The maximum adsorption capacities at equilibrium of the coated particles of PP and GB were achieved with the chitosan suspension, being the values of around 800 mg g^-1. Thus, the chitosan-coated polyethylene particles showed to be a promising adsorbent for fixed bed column. Graphical abstract.