The stability of three different citrus oil-in-water emulsions fabricated by spontaneous emulsification

Enzymatically produced acylglycerol and glycerin monostearate additives improved the characteristics of gelatin-stabilized omega-3 emulsions and microcapsules

The impacts of enzymatically produced acylglycerol and glycerin monostearate on the characteristics of gelatin-stabilized omega-3 emulsions and microcapsules were investigated. Tuna oil was enzymatically produced and the resulting acylglycerol was mixed with tuna oil at 12.5% (w/w) to prepare a novel oil phase. This oil phase was stabilized by gelatin to prepare oil-in-water emulsions and subsequent microcapsules via complex coacervation. The tuna oil with glycerin monostearate (GMS) at 1 and 2% (w/w) were used as controls. Results showed that both acylglycerol and GMS significantly reduced the emulsion droplet size and zeta potential, while increasing the viscoelasticity and stability. The diacylglycerol/monoacylglycerol were involved in the oil/water interfacial layer formation by lowering interfacial tension and increasing droplet surface hydrophobicity. Overall, the changed emulsion properties promoted the complex coacervation and contributed to the formation of microcapsules with improved oxidative stability. Therefore, enzymatically produced acylglycerol can develop high-quality stable omega-3 microencapsulated novel food ingredients.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

Optimization of vitamin B12 nano-emulsification and encapsulation using spontaneous emulsification

In this study, the use of low-energy methods for nanoemulsification of vitamin B12 was investigated to protect this bioactive substance. The effects of sunflower oil concentrations (4-8%), Tween 80 (8-16%), and vitamin B12 (5-15%) on the physicochemical properties of B12 nanoemulsion were evaluated using response surface methodology (RSM). The results indicated that the quadratic model was the most fitting model for experimental data. Optimization revealed that the optimal formulation contained 6.5% sunflower oil, 9.6% Tween 80, and 13% vitamin B12, resulting in maximum efficiency, viscosity, and vitamin B12 content, as well as minimum pH, turbidity, p-Anisidine index, particle size, and polydispersity index (PDI). Under optimal conditions, pH, viscosity, turbidity, efficiency, vitamin B12, p-Anisidine index, PDI, and particle size were 7.24, 17.0024 cp, 2.19, 51.98%, 5.54 ppm, 0.01, 0.34, and 322 nm, respectively. This study highlights the effectiveness of spontaneous emulsification as a carrier for the encapsulation of bioactive compounds.

Citrus essential oils - Based nano-emulsions: Functional properties and potential applications

Citrus essential oils are natural products with various bioactive properties (e.g., antimicrobial, antioxidant, and antimutagenic activities), that are generally recognized as safe (GRAS) by Food and Drug Administration (FDA) to be used as flavorings and food additives. Nonetheless, due to their high volatility, low solubility in water, low thermal stability, susceptibility to oxidation, and strong flavor, their applications in the food industry are limited. Nanotechnology allows the incorporation of citrus essential oils into nano-emulsion systems, thus protecting them from the deterioration caused by external factors and maintaining or even improving their functional properties. This study aims to summarize the antioxidant, antimicrobial, and antimutagenic effects of the nano-emulsions based on essential oils from citrus peels with emphasis on their mechanisms of action and potential applications in, e.g., foods, pharmaceuticals, and cosmetics.

Preservation of Fresh-Cut 'Maradol' Papaya with Polymeric Nanocapsules of Lemon Essential Oil or Curcumin

Papaya is one of the most consumed fruits in the world; however, tissue damage caused by cuts quickly leads to its decay. Therefore, this study aimed to prepare and characterize lemon oil and curcumin nanocapsules to evaluate their capacity for preserving fresh-cut papaya. Lemon essential oil and curcumin nanocapsules were prepared using ethyl cellulose (EC) and poly-(ε-caprolactone) (PCL) by the emulsification-diffusion method coupled with ultrasound. The particles had sizes smaller than 120 nm, with polydispersity indices below 0.25 and zeta potentials exceeding -12 mV, as confirmed by scanning electron microscopy. The nanoparticles remained stable for 27 days, with sedimentation being the instability mechanism observed. These nanoparticles were employed to coat fresh-cut papaya, which was stored for 17 days. The results demonstrated their remarkable efficacy in reducing the respiration rate. Furthermore, nanocapsules maintained the pH and acidity levels of the papayas for an extended period. The lemon oil/EC nanocapsule treatment retained the color better. Additionally, all systems exhibited the ability to minimize texture loss associated with reduced pectin methylesterase activity. Finally, the nanocapsules showed a notable reduction in polyphenol oxidase activity correlating with preserving total phenolic compounds in the fruit. Therefore, the lemon oil and curcumin nanoparticles formed using EC and PCL demonstrated their effectiveness in preserving fresh-cut 'Maradol' papaya.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 → and →4)-α-GalpA-6-O-methyl-(1→, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

Research advances of in vivo biological fate of food bioactives delivered by colloidal systems

Food bioactives exhibit various health-promoting effects and are widely used in functional foods to maintain human health. After oral intake, bioactives undergo complex biological processes before reaching the target organs to exert their biological effects. However, several factors may reduce their bioavailability. Colloidal systems have attracted special attention due to their great potential to improve bioavailability and bioefficiency. Herein, we focus on the importance of in vivo studies of the biological fates of bioactives delivered by colloidal systems. Increasing evidence demonstrates that the construction, composition, and physicochemical properties of the delivery systems significantly influence the in vivo biological fates of bioactives. These results demonstrate the great potential to control the in vivo behavior of food bioactives by designing specific delivery systems. We also compare in vivo and in vitro models used for biological studies of the fate of food bioactives delivered by colloidal systems. Meanwhile, the significance of the gut microbiota, targeted delivery, and personalized nutrition should be carefully considered. This review provides new insight for further studies of food bioactives delivered by colloidal systems, as well as scientific guidance for the reasonable design of personalized nutrition.

Influence of Surfactant Concentration on Spontaneous Emulsification Kinetics

The kinetics of spontaneous emulsification is investigated on aqueous pendant drops in paraffin oil. Optical microscopy in transmission mode is used for high-spatial-resolution image recording. The influence of a lipophilic surfactant (Span 80) and two water-soluble surfactants (CTAB and SDS) is investigated. As time runs, the drop interface turns opaque due to the formation of microstructures associated with spontaneous emulsification. The time evolution of this phenomenon is shown to depend upon temperature and surfactant concentration, which leads to an overall shrinkage due to gradual water uptake and transport into paraffin oil. Spontaneous emulsification kinetics depends upon the chemical composition. Higher concentrations of Span 80 and CTAB (resp. SDS) are shown to promote (resp. hinder) water transport. This work provides new insights into the understanding of spontaneous emulsification when combining the properties of non-ionic and ionic surfactants.

Flavoring properties that affect the retention of volatile components during encapsulation process

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Flavor retention during encapsulation.

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Emulsion stability plays an important role in the encapsulation efficiency.

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Protection of sensitive compounds can be improved using an optimized formulation.

Flavorings are widely used in food and beverage industries and spray drying is the most cost-effective encapsulation technique to deliver stable products. Generally, the same slurry is used to encapsulate both hydrophilic and hydrophobic flavors which led sometimes to lower retention. The same slurry formulation composed by Modified Starch and Maltodextrin 20DE was loaded with 35% of two different flavorings (orange and passion fruit) and, spray dried under the same conditions. The flavorings selected had different octanol/water partition coefficients and their composition affected the emulsion stability. Orange flavoring presented clearly better emulsion stability than passion fruit flavoring, confirmed by size distribution and Turbiscan Stability Index (TSI _orange ≪ TSI _{passion fruit}). A key learning from this work is that the best infeed emulsion achieved by the most hydrophobic flavoring, presented the lowest droplet size and yielded in final bigger particle size and the best encapsulation efficiency result (>92%).

Characteristics of two cedarwood essential oil emulsions and their antioxidant and antibacterial activities

Cedarwood essential oil (CEO) has the effect of anti-inflammatory and anti-bacteria. However, the application of this essential oil is limited due to its strong volatility and poor water solubility. To address this issue, two types of oil-in-water CEO emulsions including CEO nanoemulsion (CEO-NE) and CEO Pickering emulsion (CEO-PE) were prepared. CEO-NE with 5% surfactant, had a smaller particle size (135.14 ± 1.1 nm) and higher absolute zeta potential value (32.75 mV) compared with CEO-PE (1% starch) which particle size was 626.21 ± 6.05 nm, zeta potential was 27.58 mV. The stability of CEO-NE and CEO-PE were tested by multiple light scattering, results showed that Turbiscan Stability Index (TSI) value of CEO-NE was much lower than that of CEO-PE. CEO-NE and CEO-PE exerted higher free radical scavenging activities, iron reducing power and antibacterial ability than CEO itself. These results indicated that emulsification is a feasible method to extend application of CEO.

Fabrication of zein/alginate delivery system for nanofood model based on pumpkin

Gastrectomy is among the most crucial types of surgeries proposed to treat gastric cancer and obesity. Gastrectomy patients experience difficulties such as energy deficit, anorexia, and malnutrition. The objective of the present study was to introduce nanofood as a fruitful strategy to supply the needed energy and nutrients for these patients and particularly control the release of proteins, lipids, and carbohydrates on the simulated gastrointestinal tract (GIT). Cooked pumpkin puree (CPP), sodium caseinate, sesame oil, rice bran oil, rice starch, sugar and pectin were applied to prepare oil in water nanoemulsion. Six delivery systems were prepared including various concentrations of zein (0.02-0.15% w/v) and alginate (0.01-0.16% w/v) in acidic (2.45-2.81) and alkaline (11.45-11.82) pH ranges. The particle size (83.5-207.0 nm) and calorific values (467.2-498.4 Cal/100 g) of samples were measured. Encapsulated food matrix nanoemulsion with zein/alginate's biopolymers delivery system (0.15:0.16 w/v, pH = 8.30) with 489.9 Cal/100 g exhibited the least digestible nutrients in the mouth (0.10%>) and gastric phase (6.91%>). It has high release nutrients in the small intestine phase (72.14%>). Therefore, it is introduced as the optimal formulation. The use of CPP in nanoemulsion formulation besides other ingredients is a good strategy to prepare nanofood for gastrectomy patients.

Food-Grade Nanoemulsions: Preparation, Stability and Application in Encapsulation of Bioactive Compounds

Nanoemulsions have attracted significant attention in food fields and can increase the functionality of the bioactive compounds contained within them. In this paper, the preparation methods, including low-energy and high-energy methods, were first reviewed. Second, the physical and chemical destabilization mechanisms of nanoemulsions, such as gravitational separation (creaming or sedimentation), flocculation, coalescence, Ostwald ripening, lipid oxidation and so on, were reviewed. Then, the impact of different stabilizers, including emulsifiers, weighting agents, texture modifiers (thickening agents and gelling agents), ripening inhibitors, antioxidants and chelating agents, on the physicochemical stability of nanoemulsions were discussed. Finally, the applications of nanoemulsions for the delivery of functional ingredients, including bioactive lipids, essential oil, flavor compounds, vitamins, phenolic compounds and carotenoids, were summarized. This review can provide some reference for the selection of preparation methods and stabilizers that will improve performance in nanoemulsion-based products and expand their usage.

Citrus Oil Emulsions Stabilized by Citrus Pectin: The Influence Mechanism of Citrus Variety and Acid Treatment

Citrus pectin and citrus oil are the main functional components of citrus residuals in the processing industry. In this study, citrus oil emulsions were fabricated for the first time using four different citrus pectins (orange, mandarin, grapefruit, and commercial citrus pectins) as the emulsifier. The influence mechanism of citrus variety and acid treatment (pH 1, 2, 3, 4, 5, 6, and 7) on the emulsifying capacity of citrus pectins was systematically investigated by understanding the relationship between molecular structure, solution property, interfacial property, and emulsion property. The results suggest that citrus variety and acid treatment can significantly influence the emulsifying capacity in relation to the molecular structure and molecular state of citrus pectins. A smaller molecular size of citrus pectin and lower pH between 2 and 7 produced a reduction in aggregate size, which improved the interfacial capacity and emulsifying ability by promoting their distribution at the interface. Although hydrolyzed citrus pectins at pH 1 with a lower molecular size exhibited better interfacial capacity, citrus oil emulsions were unstable due to electrostatic attraction caused by partially positive charged citrus pectins. Fine stable citrus oil emulsion was prepared using mandarin pectin with a relative high methyl ester content and small molecular size at pH 2. Our results provide a scientific basis for the fabrication of citrus oil emulsion based on citrus pectin and facilitate the application of citrus residuals in the food industry.