Eugenol improves physical and chemical stabilities of nanoemulsions loaded with β-carotene

Self-assembly of sophorolipid and eugenol into stable nanoemulsions for synergetic antibacterial properties through alerting membrane integrity

Exploring the natural, safe, and effective antimicrobial is one of the preferable ways to control foodborne bacteria. In this work, novel oil-in-water nanoemulsions were formulated with sophorolipids and eugenol without any co-surfactant using a self-assembling strategy. These nanoemulsions showed high stability with sizes less than 200 nm when exposure to low concentrations of salt ions, various pH values (5.0, 7.0, 10.0), storage temperature and time. The synergistic antibacterial effects against both Gram-negative Escherichia coli and Gram-positive Bacillus cereus were determined with a minimum inhibitory concentration (MIC) value of 0.5 mg/mL and 0.125 mg/mL, respectively. Further microscopy (SEM, TEM, LCSM) examination and ATP/Na+-K+-ATPase assay results showed that the morphological changes, intensive cell membrane permeability, leakage of ATP, and decreased Na+-K+-ATPase contributed to the antibacterial effects. Moreover, the bonding mechanism between nanoemulsions and cell membranes were further evaluated by FTIR and ITC using a DPPC vesicle model, which demonstrated that the nanoemulsions adsorbed on the surface of bilayer, interacted with the hydrophobic chains of DPPC membrane mainly through the hydrophobic interaction, and altered the structural integrity of the lipid bilayer. These results not only provide a facile green strategy for fabricating stable nanoemulsions, but also highlight a new perspective for stabilizing essential oils for their widely application in food industry.

Improving stability and bioavailability of curcumin by quaternized chitosan coated nanoemulsion

This study aims to enhance the stability and bioavailability of curcumin (Cur) using nanoemulsion coating technology. The nanoemulsion system was developed by encapsulating Cur with quaternized chitosan (QMNE), and the nanoemulsion containing Cur and medium-chain triglyceride (MCT) oil (MNE) was used as control sample. The microstructure of the nanoemulsion was examined using Dynamic light scattering (DLS), Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The storage, thermal, ionic strength, and pH stability of QMNE were also evaluated, respectively. The results indicate that QMNE demonstrates superior stability, in vitro gastric fluid stability, bioavailability compared to MNE. QMNE exhibits excellent emulsification activity and stability. In addition, QMNE shows significant protection against oxidation in both emulsion systems after different heat treatments. The antimicrobial activity results reveal that QMNE exhibits greater efficacy than that of MNE. Consequently, this study provides valuable insights into the formulation of a system to encapsulate Cur and the improvement of its stability and bioavailability.

Enhancing the stability of lutein emulsions with a water-soluble antioxidant and a oil-soluble antioxidant

Lutein is critical for protecting the eye against light damage. The low solubility and high sensitivity of lutein to environmental stresses prevent its further application. The hypothesis is that the combination of one water-soluble antioxidant and one oil-soluble antioxidant will be beneficial to improve the stability of lutein emulsions. A low-energy method was performed to prepare lutein emulsions. The combination of a lipid-soluble antioxidant (propyl gallate or ethylenediaminetetraacetic acid) and a water-soluble antioxidant (tea polyphenol or ascobic acid) were investigated for improving the lutein retention rates. It was shown that the highest lutein retention rate was achieved by using propyl gallate and tea polyphenol, 92.57%, at Day 7. It was proven that the lutein retention rates of emulsions with propyl gallate and tea polyphenol were 89.8%, 73.5% and 55.2% at 4 °C, 25 °C and 37 °C, respectively, at Day 28. The current study is helpful to prepare for the further application of lutein emulsions for ocular delivery.

Lycopene-loaded emulsions stabilized by whey protein covalently modified with pectin or/and chlorogenic acid: Enhanced physicochemical stability and reduced bio-accessibility

Lycopene-loaded emulsions were formulated with whey protein isolate (WPI) covalently modified with high methoxylated pectin (HMP) or/and chlorogenic acid (CA) prepared by dry heating or/and alkali grafting. Covalent WPI products were confirmed by SDS-PAGE and degree of graft/CA binding equivalent values. The α-helix and β-sheet percentage, surface hydrophobicity and fluorescence intensity of WPI decreased significantly (p < 0.05) upon binding. Both binary and ternary complexes enhanced the stability of the emulsions, and lycopene retained more after UV irradiation, thermal treatment, storage, compared with emulsions stabilized by WPI, with the best protection by both ternary complexes. In vitro simulated digestion results showed that free fatty acids were released in the order of WPI > WPI-HMP > WPI-CA > WPI-HMP-CA ≈ WPI-CA-HMP. Bio-accessibility analysis showed the same trend as the fatty acid release rate. These results may provide a theoretical basis for applications of conjugating protein with polysaccharide or/and polyphenol emulsions.

Fabrication of alkali lignin-based emulsion electrospun nanofibers for the nanoencapsulation of beta-carotene and the enhanced antioxidant property

For the greater utilization of β-carotene in antioxidant material, β-carotene-loaded emulsion stabilized by alkali lignin (AL) was successfully electrospinning with poly (vinyl alcohol) (PVA) (PVA/AL/β-carotene nanofiber). Transmission electron microscopy demonstrated the core-shell structure of nanofiber with the average diameter being 356.31 nm, and 85.7 % of β-carotene was effectively encapsulated into the core section. Fourier transform infrared spectra and differential scanning calorimetry revealed the good compatibility and decreased crystallinity of β-carotene, favoring its stability and solubility, respectively. As expected, the PVA/AL/β-carotene nanofiber exhibited higher antioxidant activity than free β-carotene due to the protection of AL matrix and the special structure of nanofiber, as the DPPH free radical scavenging rate being 90.7 % at 7th day. The sustained release behavior of β-carotene and AL from fiber followed Fickian diffusion model, contributing to the greater protection for fish oil than that of emulsion. Thus, this study provides an approach to develop hydrophobic compounds-loaded emulsion electrospun antioxidant material with controlled release property and enhanced activity.

Preparation, characterization, and gel characteristics of nanoemulsions stabilized with dextran-conjugated clam Meretrix meretrix linnaeus protein isolate

In this study, the stability and flavor characteristics of nanoemulsions prepared with dextran-conjugated Meretrix meretrix clam protein isolate were studied by characterizing particle size, polydispersity index, zeta potential, turbidity, microstructure, e-tongue, e-nose and HS-GC-IMS. Compared with the N_CPI (CPI nanoemulsions) and N_{CPI-Dex Mix} (CPI-Dex Mix nanoemulsions), the N_{CPI-Dex Con} (CPI-Dex Con nanoemulsions) has better stability and flavor. The breaking strength and breaking strain of clam sausages were significantly (P > 0.05) affected by the addition of N_{CPI-Dex Con}. The gel strength with 8% N_{CPI-Dex Con} was the highest (5122.08 g‧mm), a 51.07% increase compared with the control group (3390.58 g‧mm). The clam sausages supplemented with the 8% N_{CPI-Dex Con} had the highest sensory score, with the densest and the most uniform gel structure. Therefore, CPI-Dex Con stabilized nanoemulsions could effectively improve the gel property and flavor of the clam sausages.

Improved stability and aqueous solubility of β-carotene via encapsulation in self-assembled bioactive oleanolic acid nanoparticles

Poor water solubility and stability of β-carotene (Car) greatly hinder its application in foods. Herein, naturally occurring bioactive oleanolic acid (OA) was used as a nanocarrier to overcome these shortcomings by fabricating Car-loaded OA nanoparticles (Car/OA NPs). Through optimization, the encapsulation efficiency and loading capacity reached 80.7% and 32.6%, respectively. Systematic characterization suggested that Car was successfully encapsulated, and hydrogen bonding and hydrophobic interactions are the main forces facilitating the self-assembly and encapsulation. Compared with free Car, Car/OA NPs exhibited significantly improved water dispersibility and enhanced stability against UV radiation, heat, ionic strength, and acidic conditions. Further, Car/OA NPs provided gastric protection, delayed-release in simulated gastric fluid (SGF) and controlled release in simulated intestinal fluid (SIF). Additionally, both OA NPs and Car/OA NPs showed markedly inherent hepatoprotective effects. This work demonstrates that OA NPs can be used as inherent bioactive nanocarriers to deliver hydrophobic nutrients and bioactive food components.

Formulation, Characterization, and In Vitro Mineral Absorption of Ficus Palmata Fruit Extract Nanoemulsion

OBJECTIVE

Loss of vital bioactive components of Ficus palmata fruit extract during food processing is a major issue. Therefore, to retain the antioxidant potential and to increase the mineral bioavailability, gum arabic stabilized nanoemulsion of Fig fruit extract was prepared.

METHOD

. Nanoemulsion was formulated using three different levels (1, 3, and 5%) of fig extract, however, to optimize the fig extract concentration, the amount of gum arabic and linoleic acid was kept constant.

RESULTS

The average droplet size of nanoemulsion was observed in the range of 22.88-37.87 nm, whereas the Fourier Transform Infrared (FTIR) Spectroscopy confirmed the presence of functional groups in the emulsion system. Also, increased ionic concentration significantly (p < 0.05) increased the average droplet size and zeta potential of nanoemulsion during storage. Increased shear rate and temperature unveiled a slight decrease in apparent viscosity of the nanoemulsion. Non-significant (p < 0.05) difference in TBA value confirmed the oxidative stability of the emulsion. Significantly (p < 0.05) higher mineral bioavailability for calcium was observed as compared to iron and zinc.

CONCLUSION

Our results manifested improved anti-oxidant activity, mineral bioavailability, and oxidative stability of Fig extract nanoemulsion, suggesting its potential use as a therapeutic alternative.

An overview of nanoemulsion characterization via atomic force microscopy

Nanoemulsion-based systems are widely applied in food industries for protecting active ingredients against oxidation and degradation and controlling the release rate of active core ingredients under particular conditions. Visualizing the interface morphology and measuring the interfacial interaction forces of nanoemulsion droplets are essential to tailor and design intelligent nanoemulsion-based systems. Atomic force microscopy (AFM) is being established as an important technique for interface characterization, due to its unique advantages over traditional imaging and surface force-determining approaches. However, there is a gap in knowledge about the applicability of AFM in characterizing the droplet interface properties of nanoemulsions. This review aims to describe the fundamentals of the AFM technique and nanoemulsions, mainly focusing on the recent use of AFM to investigate nanoemulsion properties. In addition, by reviewing interfacial studies on emulsions in general, perspectives for the further development of AFM to study nanoemulsions are also discussed.

Application of whey protein isolate fibrils in encapsulation and protection of β-carotene

β-Carotene (BC) exhibits several bioactive properties, but its application is restrained due to the unstability and low biological availability. In this study, protein fibrils were prepared from whey protein isolate fibrils (WPIF), which were used as carriers to protect and deliver BC. With the extension of heating time, the molecular weight of WPI decreased gradually. WPI was hydrolyzed into peptides which self-assembled into WPIF, resulting in significant changes in secondary structure, zeta-potential, viscosity and, antioxidant capacity. The main interactions between WPIF and BC were hydrogen bonding and hydrophobic interaction. The encapsulation efficiency of WPIF₂₄ was increased from 76.55% to 92.11% compared to that of untreated WPI. Moreover, the simulated gastrointestinal release showed that the cumulative release of BC encapsulated by WPIF₂₄ reached the maximum in the simulated intestine. Therefore, WPIF could be a potential delivery system for water-insoluble bioactive compounds with enhanced encapsulation efficiency and protection effect.

Casein-maltodextrin Maillard conjugates encapsulation enhances the antioxidative potential of proanthocyanidins: An in vitro and in vivo evaluation

Practical application of proanthocyanidins (PAs) as antioxidants is limited because of their hard-to-maintained activities during the processes and storage and in severe gastrointestinal environments. To overcome this challenge, we have developed an easy and green method to encapsulate PAs based on casein-maltodextrin Maillard conjugates. The current work entails the systematic study on the antioxidative potentials of fabricated casein-maltodextrin-PAs nanoparticles (CMPNs). In vitro antioxidant activities of CMPNs remained well during storage in 28 days and treatments under 40-80 °C. In vivo Caenorhabditis elegans (C. elegans) model further showed that the CMPNs could prolong the lifespan of nematodes and protected nematodes from oxidative stress and heat shock. Analyses of intracellular superoxide dismutase and catalase activities also confirmed the existence of an antioxidant protective effect. Besides, in vitro release test showed that the encapsulation enhanced the bioaccessibility of PAs. These results have important implications for the development of novel antioxidants in nutraceutical industries.

Effect of surfactant concentration and sterilization process on intraocular pressure-lowering activity of Δ9-tetrahydrocannabinol-valine-hemisuccinate (NB1111) nanoemulsions

The use of Δ⁹-tetrahydrocannabinol (THC) and Δ⁹-tetrahydrocannabinol-valine-hemisuccinate (THC-VHS; NB1111) has recently been investigated in the management of intraocular pressure (IOP). The current study was undertaken to develop an optimized THC-VHS-loaded nanoemulsion formulation (NE; THC-VHS-NE) that could improve the drug load and duration of activity. THC-VHS-NE formulation was prepared by homogenization followed by ultrasonication. Sesame oil, Tween®80, and Poloxamer®188 were used as the oil, surfactant, and cosurfactant, respectively. Stability of the optimized THC-VHS-NE formulation was observed at 4 °C. The IOP lowering effect of the lead formulations, commercial timolol, and latanoprost ophthalmic solutions, as well as an emulsion in Tocrisolve™ (THC-VHS-TOC), was studied in New Zealand White rabbits following topical administration. The effect of surfactant concentration and sterilization process on IOP-lowering activity was also studied. THC-VHS-NE formulations (0.5, 1.0, and 2.0% w/v) showed dose dependent duration of action. The 1.0%w/v THC-VHS-NE formulation was selected for further evaluation because of its desirable physical and chemical characteristics. THC-VHS-NE formulation prepared with 2% w/v Tween®80 exhibited a higher drop in IOP than the 0.75 and 4.0% w/v of Tween®80 containing formulations. The IOP-lowering duration was, however, similar for the formulations with 0.75 and 2.0% Tween®80, while that with 4.0% Tween®80 was shorter. THC-VHS-NE formulation produced a greater drop in IOP (p < 0.05) and a longer duration of activity compared to THC-VHS-TOC, latanoprost, and timolol. The formulation could be sterilized by filtration without impacting product attributes. Overall, the optimized THC-VHS-NE formulation demonstrated a significantly better IOP reduction profile in the test model compared to the commercial ophthalmic solutions evaluated.

Role of antioxidants on physicochemical properties and in vitro bioaccessibility of β-carotene loaded nanoemulsion under thermal and cold plasma discharge accelerated tests

The effects of water soluble antioxidant (ascorbic acid and EDTA), fat soluble antioxidant (α-tocopherol) and amphiphilic antioxidant (ascorbyl palmitate; AP) on the chemical physics and bioaccessibility of β-carotene loaded nanoemulsions (CNE) were investigated. During accelerated storage at 45 °C for 15 days, AP showed the highest protective actions against particle size growth, color fading, lipid oxidation, and β-carotene degradation in CNE (p < 0.05). CNE with AP was then subjected to treat with cold plasma (CP) induced reactive species system under various powers and contact times compared to control. AP was able to protect physical and oxidative stabilities of CNE as well as β-carotene integrity. The highest in vitro lipid digestibility, bioaccessibility and β-carotene stability were found in CNE with AP (p < 0.05). However, those properties were lowered after CP exposure. The results indicated that AP was a promising antioxidant in improving physical stability, oxidative stability, β-carotene retention, and β-carotene bioaccessibility of CNE.

Improving the Stability of Lycopene from Chemical Degradation in Model Beverage Emulsions: Impact of Hydrophilic Group Size of Emulsifier and Antioxidant Polarity

The chemical stability of the lipophilic bioactives encapsulated in emulsions can be influenced by emulsion droplet interfacial characteristics as well as by the ability of antioxidants incorporated in emulsion to prevent the degradation of the encapsulated compounds. Therefore, this study evaluated the effects of the interfacial characteristics of emulsions and the polarity of antioxidants on the storage stability of lycopene in emulsions. Emulsions with 5% (w/w) oil containing lycopene (30 µmol/kg emulsion) were prepared using a series of polyethylene glycol acyl ether-type emulsifiers through microfluidization. Change in lycopene content in emulsions was monitored by high performance liquid chromatography. Our findings show that the hydrophilic group size (or length) of emulsifiers and the emulsifier concentration at the interfacial film play a role, albeit minor, in controlling the storage stability of lycopene encapsulated in emulsions. Lipophilic (tert-butylhydroquinone (TBHQ)) and amphiphilic (lauryl gallate) antioxidants similarly improved the storage stability of lycopene in emulsions from acid- and radical-mediated degradation, independent of the characteristics of interfacial films of emulsions. However, TBHQ inhibited the degradation of lycopene in emulsions more effectively than lauryl gallate under conditions intended to accelerate the acid-mediated degradation of lycopene. Therefore, our findings can provide helpful information about what type of emulsifiers and antioxidants can be chosen for preparing food emulsions capable of maximizing the stability of lycopene encapsulated therein.

Effects of environmental stresses on physiochemical stability of β-carotene in zein-carboxymethyl chitosan-tea polyphenols ternary delivery system

β-Carotene is a natural nutrient that serves as a natural food colorant. However, the weak physical stability restricts its development in food industrial production. Here, the influences of a variety of external environmental conditions on the stability of β-carotene enriched zein-carboxymethyl chitosan (CMCS)-tea polyphenols (TP) ternary composite nanoparticles were investigated. Compared with zein unitary and zein-CMCS binary complexes, it was interesting to note that ternary complexes had the best stability against color fading and there was little impact on its nanoparticle size during storage with change in temperature. Besides excellent antioxidant properties, ternary complexes were extremely effective in inhibiting β-carotene color degradation when exposed to ultraviolet light. Based on our results, the novel zein-CMCS-TP nanoparticles are expected to be an effective delivery system to encapsulate hydrophobic bioactive compounds, which is a promising approach to improve their storage stability against external environmental stresses.

Preparation and characterisation of novel water-soluble β-carotene-chitooligosaccharides complexes

β-carotene and chitooligosaccharides are bioactive compounds that find their application in the food industry as well in biomedical fields. However, the application of β-carotene is limited due to its very low water solubility, as well as its air, light and temperature sensitivity. The preparation of β-carotene-chitooligosaccharides complexes by mechanochemical methods was presented. Their physical and chemical properties including solubility, size, zeta potential and radical scavenging activity were investigated. The interaction of the two components was shown by NMR, FT-IR, and Raman spectroscopy. The complexes were analysed by scanning and transmission electron microscopy. Chitooligosaccharides could serve as a carrier for β-carotene delivery. The complexation did not cause the loss of the radical scavenging activity of β-carotene and guaranteed its water solubility.

Synthesis, characterization and cellular mineral absorption of nanoemulsions of Rhododendron arboreum flower extracts stabilized with gum arabic

To assess the cellular mineral uptake and oxidative stability of flower extract, a nanoscale gum arabic stabilized Rhododendron arboreum flower extract emulsion was formulated. Four different concentrations of flower extract (1-5%) were used for the optimization of the nanoemulsion. A significant (P < 0.05) difference was observed in average droplet size (43.51-55.87 nm) of the nanoemulsion. FTIR spectrum confirmed mainly C=C, aliphatic C-H, aliphatic and aromatic galacto-proteins, and polymeric-OH groups present in nanoemulsion. Smooth type of nanoemulsion was confirmed by inverted light microscopy. Ionic strength was evaluated and significant (P < 0.05) increase in particles size was attributed, whereas significant (P < 0.05) decrease in zeta potential was observed by increased NaCl concentration. Iron and calcium showed a non-significant difference in terms of mineral bioavailability. Calcium revealed significantly higher cellular uptake (52.11%) in comparison with iron (50.25%) and zinc (45.32%) during transwell assay. Higher cellular iron uptake unveiled a satisfactory amount of ferritin content.

Effect of Surfactant Concentrations on Physicochemical Properties and Functionality of Curcumin Nanoemulsions Under Conditions Relevant to Commercial Utilization

Surfactants are used to stabilize nanoemulsions by protecting their physical stability and preventing deterioration of the entrapped bioactive during processing and storage. The effect of surfactant concentration on physical-chemical properties of nanoemulsions with entrapped curcumin, relevant to commercial applications, was addressed in this research. Furthermore, the functionality of nanoemulsified curcumin in terms of lipid oxidation inhibition was determined. Protection against varying pH and thermal treatments was more significant in the nanoemulsions at the elevated surfactant level, but at these high concentrations, the surface charges of the emulsions dramatically decreased under sodium salt addition, which may result in instability over time. Nanoemulsions showed the potential to inhibit malondialdehyde (MDA) formulation by protecting the entrapped curcumin and enhance its antioxidant activity when added to milk. The fortified milk with added curcumin systems had a yellow color compared to the control. The results of the study are critical in choosing the surfactant concentration needed to stabilize emulsified curcumin, and to protect the entrapped curcumin under specific conditions of use to support the utilization of curcumin nanoemulsions as a food additive in different commercial products.

Physical and chemical stability of β-carotene nanoemulsions during storage and thermal process

Nanotechnology has become an option for the encapsulation of compounds, such as carotenoids. However, for the incorporation in to food, it is necessary to develop nanometric systems that are stable under the different conditions to which the food is submitted during its production, transport, and storage. Thus, with the intent to develop a stable nanoemulsion formulation for food application, the physical and chemical stability of β-carotene nanoemulsions after thermal treatments and storage under different conditions, were investigated in this work. The β-carotene nanoemulsions were formulated with corn oil, by applying high-pressure homogenization, with an average size in the 300 nm range, which is within the appropriate scale for industrial preparations, such as foods and cosmetics. The nanoemulsion droplets had negative charge (more than -25 mV) and monodisperse profile. The sample were pasteurized, sterilized, and stored at 4, 25, and 37 °C in the presence and absence of light for up to 90 days. Following the heat treatments and storage, the nanoemulsions showed no evidence of physical destabilization, retaining 70-80% of the carotenoid after the pasteurization and sterilization processes, and 70% when stored at 4 °C without light, respectively. Overall, our findings provide new information about the physical and chemical stability of β-carotene nanoemulsions during traditional thermal processes and environmental conditions.

Influence of Oxygen-Containing Sulfur Flavor Molecules on the Stability of β-Carotene under UVA Irradiation

The influence of 11 kinds of oxygen-containing sulfur flavor molecules was examined on β-carotene stability under UVA irradiation in ethanol system. Both the effects of sulfides on dynamic degradation of β-carotene and the relation between structure and effect were investigated. The oxidation products of β-carotene accelerated by sulfides under UVA irradiation were also identified. The results indicated that the disulfides had more obvious accelerative effects on the photodegradation of β-carotene than mono sulfides. The degradation of β-carotene after methyl (2-methyl-3-furyl) disulfide (MMFDS), methyl furfuryl disulfide (MFDS) and bis(2-methyl-3-furyl) disulfide (BMFDS) exposure followed first-order kinetics. Furan-containing sulfides such as MMFDS and BMFDS showed more pronounced accelerative effects than their corresponding isomers. The oxidation products were identified as 13-cis-β-carotene, 9,13-di-cis-β-carotene and all-trans-5,6-epoxy-β-carotene. These results suggest that both the sulfur atom numbers and the furan group in oxygen-containing sulfides play a critical role in the photooxidation of β-carotene.

Enhancing the antitumor activity of tea polyphenols encapsulated in biodegradable nanogels by macromolecular self-assembly

Nanogels (NGs) with desirable stability have emerged as a promising platform for biomedical applications. Herein, a convenient approach was developed to encapsulate and protect tea polyphenols (TPs) by macromolecular self-assembly of lysozyme (Ly) and carboxymethyl cellulose (CMC) through a heating treatment. Biodegradable Ly–CMC NGs were formed on the basis of molecules driven by electrostatic interaction and hydrophobic forces. The particle size and morphology of the Ly–CMC NGs were analyzed using a Malvern particle size analyzer, fluorescence spectrophotometer, and scanning electron microscope. The results showed that the heated NGs were spherical with better stability and smaller particle size. The encapsulation efficiency of TP-loaded NGs was 89.05 ± 3.14%, and it indicated that the Ly–CMC NGs may have a strong binding force with TPs. Moreover, TP-loaded NGs showed a sustained release feature. The DPPH and ABTS-scavenging rates of the TP-loaded NGs were 76.5% and 86.1%, respectively. The antitumor activity of the TP-loaded NGs can effectively inhibit the proliferation of HepG₂ cells. Furthermore, TP-loaded NGs were proven to significantly enhance the induction of apoptosis in hepatoma cells and exhibit obvious cell cycle arrest. Our results demonstrate that the Ly–CMC NGs have extensive application prospects as a biocompatible and biodegradable delivery carrier of food functional factors to improve their antitumor effects.

Fabrication of biodegradable TP-loaded Ly and CMC nanogels via self-assembly and the study of their controlled release and absorption process in vivo.

Insights into interaction of chlorophylls with sodium caseinate in aqueous nanometre-scale dispersion: color stability, spectroscopic, electrostatic, and morphological properties

Chlorophylls are the major pigments present in photosynthetic plants but their application in foods is limited due to their lack of solubility in aqueous media and their susceptibility to degradation during processing and storage. These problems might be overcome by the addition of sodium caseinate (NaCas) whose hydrophobic and hydrophilic groups may result in electrostatic and steric stabilization. In the present work, 1% and 3% (w/w) chlorophylls in NaCas dispersion or in ethanol (control) were prepared and their color stability under light treatment for 5 h and light-shed storage for 10 days was studied along with their interaction mechanism, using electrostatic, spectroscopic and morphological methodologies. Chlorophylls remained 58.72% and 53.84% in NaCas dispersions compared with the control (41.29% and 45.93%) after light treatment for low- and high-dose treatment, respectively, suggesting that NaCas improved the solubility and stability of the pigments. Additionally, 1% and 3% (w/w) chlorophylls in NaCas dispersion remained stable at 60.49% and 57.62% compared with the control (44.81% and 48.17%) for the 10 day storage during which the zeta-potential of the dispersions changed from −31.7 to −52.2 mV and from −36.7 to −56.2 mV with a well-defined diameter (∼221–245 nm). The data obtained from electron microscopy, together with the results of fluorescence spectroscopy, suggests that chlorophylls were entrapped in NaCas dispersions mainly via hydrogen bonds.

Stability of chlorophylls was improved with self-assembly of chlorophylls and NaCas nanoparticles via van der Waals forces and hydrogen bonds.

Nutraceuticals' Novel Formulations: The Good, the Bad, the Unknown and Patents Involved

Traditional nutraceuticals and cosmeceuticals hold pragmatic nature with respect to their definitions, claims, purposes and marketing strategies. Their definitions are not well established worldwide. They also have different regulatory definitions and registration regulatory processes in different parts of the world. Global prevalence of nutraceuticals and cosmeceuticals is noticeably high with large market share with minimal regulation compared to traditional drugs. The global market is flooded with nutraceuticals and cosmeceuticals claiming to be of natural origin and sold with a therapeutic claim by major online retail stores such as Amazon and eBay. Apart from the traditional formulations, many manufacturers and researchers use novel formulation technologies in nutraceutical and cosmeceutical formulations for different reasons and objectives. Manufacturers tend to differentiate their products with novel formulations to increase market appeal and sales. On the other hand, researchers use novel strategies to enhance nutraceuticals and cosmeceuticals activity and safety. The objective of this review is to assess the current patents and research adopting novel formulation strategies in nutraceuticals and cosmeceuticals. Patents and research papers investigating nutraceutical and cosmeceutical novel formulations were surveyed for the past 15 years. Various nanosystems and advanced biotechnology systems have been introduced to improve the therapeutic efficacy, safety and market appeal of nutraceuticals and cosmeceuticals, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. This review provides an overview of nutraceuticals and cosmeceuticals current technologies, highlighting their pros, cons, misconceptions, regulatory definitions and market. This review also aims in separating the science from fiction in the nutraceuticals and cosmeceuticals development, research and marketing.

Coupling of high-intensity ultrasound and mechanical stirring for producing food emulsions at low-energy densities

In this study, coupling of ultrasound (US) device and rotor-stator (RS), operating at low-energy densities, was studied as an alternative process to individual US and RS to produce modified starch-stabilized oil-in-water emulsions, as well as its potential use to encapsulate eugenol. To this aim, a full factorial design was employed to evaluate the effects of the US nominal power (0, 360 and 720 W) and RS nominal power (0, 150 and 300 W) on the physical properties, encapsulation efficiency and kinetic stability of emulsions produced. Firstly, the action of modified starch and eugenol onto interface oil-water was evaluated. The emulsifier was rapidly adsorbed on the interface water-sunflower oil reducing the interfacial tension from 25 to 16 mN/m, while eugenol did not show surface activity. The increase of energy density, in general, resulted in droplet size reduction, indicating the relevant role of the forces involved in the droplet breakup on emulsion stability. Coupling was more efficient on the droplets breakup producing smaller droplet size with narrower size distribution. While the coupled system work during 5 min for an energy density of 583 J/mL, the corresponding emulsification time for operating singly US and RS were 7.09 min and 17.04 min, respectively. Therefore, the main advantage associate to coupled process is the reduction of processing time to produce an emulsion with better kinetic stability.

Improved absorption of β-carotene by encapsulation in an oil-in-water nanoemulsion containing tea polyphenols in the aqueous phase

β-Carotene (BC) serves as an important source of provitamin A and natural edible pigment, but the application is limited because of its instability and low oral-bioavailability. A tea polyphenols-β-carotene (TP-BC) oil-in-water (O/W) nanoemulsion was prepared with the core oil phase containing BC and the water phase containing TP. During storage at three different temperatures (4, 25 and 35 °C), the TP-BC nanoemulsion had a better stability and higher retention rate of BC than BC nanoemulsion. An in vitro simulated digestion assay indicated that the BC recovery rates of TP-BC nanoemulsion at digestion phases I and II were significantly increased compared to the BC nanoemulsion. An in vivo absorption study showed that TP-BC nanoemulsion had higher conversion efficiency on vitamin A compared to the BC nanoemulsion. These results suggested that tea polyphenols are effective ingredients for improving the oral-bioavailability of BC.

Development of a carboxymethyl chitosan functionalized nanoemulsion formulation for increasing aqueous solubility, stability and skin permeability of astaxanthin using low-energy method

In this research, firstly astaxanthin (ASX)-loaded nanoemulsions (NEs) were produced using a convenient low-energy emulsion phase inversion method. The optimised ASX-NEs were prepared in the presence of Cremophor^® EL and Labrafil^® M 1944 CS, with a surfactant-to-oil ratio of 4:6. The ASX-NE droplets were spherical with a mean droplet diameter below 100 nm and a small negative surface charge. The system was stable without alteration of mean droplet diameter for three months. Then, the ASX-NE was functionalised with carboxymethyl chitosan (CMCS) through direct CMCS (0.02%) incorporation during the preparation process. The ASX chemical stability and skin permeability increased in the following order: ASX solution control < ASX-NE < CMCS-ASX-NE. Cell viability assays on L929 cells revealed low cytotoxicity of blank NE, ASX-NE and CMCS-ASX-NE in the range from 5 to 500 μg mL^-1. In conclusion, the CMCS-ASX-NE might be a promising delivery vehicle in dermal and transdermal products.

Emulsion design for the delivery of β-carotene in complex food systems

β-Carotene has been widely investigated both in the industry and academia, due to its unique bioactive attributes as an antioxidant and pro-vitamin A. Many attempts were made to design delivery systems for β-carotene to improve its dispersant state and chemical stability, and finally to enhance the functionality. Different types of oil-in-water emulsions were proved to be effective delivery systems for lipophilic bioactive ingredients, and intensive studies were performed on β-carotene emulsions in the last decade. Emulsions are thermodynamically unstable, and emulsions with intact structures are preferable in delivering β-carotene during processing and storage. β-Carotene in emulsions with smaller particle size has poor stability, and protein-type emulsifiers and additional antioxidants are effective in protecting β-carotene from degradation. Recent development in the design of protein-polyphenol conjugates has provided a novel approach to improve the stability of β-carotene emulsions. When β-carotene is consumed, its bioaccessibility is highly influenced by the digestion of lipids, and β-carotene in smaller oil droplets containing long-chain fatty acids has a higher bioaccessibility. In order to better deliver β-carotene in complex food products, some novel emulsions with tailor-made structures have been developed, e.g., multilayer emulsions, solid lipid particles, Pickering emulsions. This review summarizes the updated understanding of emulsion-based delivery systems for β-carotene, and how emulsions can be better designed to fulfill the benefits of β-carotene in functional foods.

Ultrasonic nanoemulsification of food grade trans-cinnamaldehyde: 1,8-Cineol and investigation of the mechanism of antibacterial activity

Using ultrasonic technology, trans-cinnamaldehyde as a natural antibacterial compound was used to prepare nano size emulsions to increase its bioavailability and therefore bactericidal action. Nanoemulsions containing trans-cinnamaldehyde as an active agent and 1,8 cineol as co additive oil (Ostwald ripening inhibitor) were formulated using probe sonicator. Three different determining factors, namely time of sonication, surfactant to oil ratio and type of emulsifier (Tween 80 and Tween 20) were investigated to enhance the stability profile. In addition, the effect of changes in the particle size and emulsifier on the antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were examined using agar dilution method. Then, the effect of optimized formulation on the membrane fluidity and cell constituent release, were investigated by analysis of membrane lipids using GC-MS and IR spectrometry, respectively. The data showed that a 15min sonication of the formulation containing Tween 80 as emulsifier with surfactant to oil ratio of 2:1 (w/w) resulted in a significant stability for 6months with considerably small particle size of 27.76±0.37nm. Furthermore, the nanoemulsion showed great antibacterial activity and could reduce the minimum inhibitory concentration (MIC) from 8 to 1mg/mL against E. coli and S. aureus, and from 16 to 2mg/mL against P. aeruginosa. Interestingly, E. coli's membrane fluidity increased dramatically after treatment with the optimum nanoemulsion (T804). This study revealed that nanoemulsion of trans-cinnamaldehyde and 1,8 cineol has substantial antibacterial activity against selected microorganisms.

Regeneration of β-Carotene from Radical Cation by Eugenol, Isoeugenol, and Clove Oil in the Marcus Theory Inverted Region for Electron Transfer

The rate of regeneration of β-carotene by eugenol from the β-carotene radical cation, an initial bleaching product of β-carotene, was found by laser flash photolysis and transient absorption spectroscopy to be close to the diffusion limit in chloroform/methanol (9:1, v/v), with a second-order rate constant (k₂) of 4.3 × 10⁹ L mol^-1 s^-1 at 23 °C. Isoeugenol, more reducing with a standard reduction potential of 100 mV lower than eugenol, was slower, with k₂ = 7.2 × 10⁸ L mol^-1 s^-1. Regeneration of β-carotene following photobleaching was found 50% more efficient by eugenol, indicating that, for the more reducing isoeugenol, the driving force exceeds the reorganization energy for electron transfer significantly in the Marcus theory inverted region. For eugenol/isoeugenol mixtures and clove oil, kinetic control by the faster eugenol determines the regeneration, with a thermodynamic backup of reduction equivalent through eugenol regeneration by the more reducing isoeugenol for the mixture. Clove oil, accordingly, is a potential protector of provitamin A for use in red palm oils.

Ultrasonic accelerates asparagine-glucose non-enzymatic browning reaction without acrylamide formation

Ultrasonic accelerated the asparagine-glucose non-enzymatic browning reaction with significant decrease of glucose and asparagine concentrations, and marked increase of intermediate products (UV-absorbance value at 294nm, Abs₂₉₄), melanoidins (UV-absorbance value at 420nm, Abs₄₂₀) and in vitro antioxidant activity (DPPH free radical scavenging activity). As the ultrasonic intensity was 17.83W/cm², the asparagine-glucose solution's Abs₂₉₄, Abs₄₂₀ and antioxidant activity increased from 0 to 1.26, 0.88 and 21.56%, respectively, and the glucose and asparagine concentrations of the asparagine-glucose solution reduced 58.97 and 12.57%, respectively. The high performance liquid chromatography (HPLC)-Diode Array Detector (DAD) analyses showed that no acrylamide was detected after 50-min ultrasonic reaction. This study suggested that ultrasonic at higher intensity was a potential method to accelerate the non-enzymatic browning reaction in the asparagine-glucose solution without acrylamide production.