Comparison of Gamma-Oryzanol Nanoemulsions Fabricated by Different High Energy Techniques

Gamma-oryzanol (GO) is a bioactive compound that, due to its biological characteristics, can be added to a food matrix. However, the bioactive compound is difficult to incorporate due to its low solubility and stability. A nanoemulsion allows substances to be packaged in nanometric sizes, improving their bioavailability. In this work, a GO nanoemulsion was developed using high-energy techniques. The methodological process began with the formulation of the coarse emulsion, where the emulsifiers (sodium caseinate and citrus pectin), diluent (rice bran oil), and pH were varied to find the most stable formulation. The coarse emulsion was subjected to four high-energy techniques (conventional homogenization, high-pressure homogenization, ultra-high-pressure homogenization, and ultrasonication) to reduce the droplet size. A physical-stability test, rheological-behavior test, image analysis, and particle-size-and-distribution test were conducted to determine which was the best technique. The formulation with the highest stability (pH 5.3) was composed of 87% water, 6.1% sodium caseinate, 0.6% citrus pectin, 6.1% rice bran oil, and 0.2% GO. The ultrasonic treatment obtains the smallest particle size (30.1 ± 1 nm), and the high-pressure treatment obtains the greatest stability (TSI < 0.3), both at 0 and 7 days of storage. High-energy treatments significantly reduce the droplet size of the emulsion, with important differences between each technique.

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

Self-stabilizing performance of γ-oryzanol in oil-in-water emulsions and solid dispersions

The surface activity of γ-oryzanol was evaluated by the pendant drop method (PDM), and its self-stabilizing properties were investigated by high-pressure homogenization (HPH) and solvent displacement method (SDM). Emulsions prepared by HPH were highly unstable due to the poor surface-active character of γ-oryzanol as identified by the PDM. In contrast, solid dispersions fabricated by SDM had comparable particle size to those prepared using Tween 80 (T80) as surfactant, and were stable up to 30 days of storage at 4 °C. The self-stabilizing properties of γ-oryzanol were attributed to the mechanism of spontaneous particle formation in SDM and to the ability of γ-oryzanol molecules to prevent particles aggregation by electrostatic repulsion. The outcome of this study indicates the potential of encapsulating selected bioactive compounds, such as γ-oryzanol, in stable colloidal systems by SDM without adding emulsifier(s), regardless of their surface-active character.

Nanoemulsion containing Yellow Monascus pigment : Fabrication, characterization, storage stability, and lipase hydrolytic activity in vitro digestion

The natural pigment of monascus is favored by human for its special coloring and physiological activity, and its development and application have attracted much attention. In this study, a novel corn oil-based nanoemulsion encapsulated with Yellow Monascus Pigment crude extract (CO-YMPN) was successfully prepared via the phase inversion composition method. The fabrication and stable conditions of the CO-YMPN including Yellow Monascus pigment crude extract (YMPCE) concentration, emulsifier ratio, pH, temperature, ionic strength, monochromatic light and storage time were investigated systemically. The optimized fabrication conditions were the emulsifier ratio (5:3 ratio of Tween 60 to Tween 80) and the YMPCE concentration (20.00% wt%)). Additionally, the DPPH radical scavenging capability of the CO-YMPN (19.47 ± 0.52%) was more excellent than each YMPCE or corn oil. Moreover, the kinetic analysis results based on Michaelis-Menten equation and constant revealed that CO-YMPN could improve lipase hydrolysis capacity. Therefore, the CO-YMPN complex had excellent storage stability and water solubility in the final water system, and the YMPCE showed brilliant stability.

Red Raspberry Seed Oil Low Energy Nanoemulsions: Influence of Surfactants, Antioxidants, and Temperature on Oxidative Stability

The aim of this study was to assess and improve the oxidative stability of red raspberry seed oil−RO, a potential topical ingredient derived from food industry by-products, on its own and when incorporated in low energy nanoemulsion (NE). The RO’s oxidative stability was assessed at 5, 25, and 40 °C during one month of storage and expressed in: peroxide value, p-anisidine, and thiobarbituric reactive substances—TBARS value, while for NEs, lipid hydroperoxides and TBARS values were monitored. Both synthetic (butylated hydroxytoluene—BHT and ethylenediaminetetraacetic acid—EDTA), and natural (oregano essential oil—ORE and oak fruit extract—OAK) antioxidants were used. Pure RO and RO with BHT or ORE were stable at 5 °C and 25 °C, but at 40 °C BHT showed only moderate protection, while ORE was prooxidant. NEs prepared with new biodegradable polyglycerol esters-based surfactants, with droplet sizes of < 50 nm and narrow size distribution, showed improved physicochemical stability at room temperature, and especially at 40 °C, compared to NEs with polysorbate 80, which required the addition of antioxidants to preserve their stability. Natural antioxidants ORE and OAK were compatible with all NEs; therefore, their use is proposed as an effective alternative to synthetic antioxidants.

Physicochemical stability and in-vitro bioaccessibility of concentrated γ-Oryzanol nanodispersions fabricated by solvent displacement method

Concentrated γ-Oryzanol nanodispersions were fabricated using milli-Q water (no emulsifier) or 0.1% (w/w) polysorbate 80 (T80), modified lecithin (ML) or sodium caseinate (SC) as emulsifiers. The freshly prepared nanodispersions had comparable particle diameter (118 to 157 nm), γ-Oryzanol concentration (1.75 to 1.92 mg mL^-1) and free-radical scavenging activity (59 to 62%) and had negative ζ-potentials (-22 to -59 mV), indicating that both γ-Oryzanol and emulsifier coexisted on the particles' interface. The nanoparticles had superior physicochemical stability up to 30 days of storage at 5 °C and were successfully autoclaved without excessive growth or aggregation. Nevertheless, they showed distinct physical stability upon storage at specific environmental conditions, which affected their In-vitro gastrointestinal digestion. Comprehensively, emulsifier-free nanodispersions were sensitive to acidic pH, NaCl and CaCl₂ addition. ML and SC coated nanoparticles were sensitive to Ca²⁺ ions, while T80 stabilized nanodispersions resisted to all environmental stresses, resulting in optimal simulated intestinal absorption.

One-pot ultrasonic cavitational emulsification of phytosterols oleogel-based flavor emulsions and oil powder stabilized by natural saponin

Phytosterols oleogel-based flavor emulsions were successfully fabricated for the first time using natural tea saponin as emulsifier and one-pot ultrasonic technique. The effects of ultrasonic time and power, surfactant concentration, and type of flavor oils (e.g., orange, lemon and peppermint) on the emulsion droplet size were investigated. Submicron emulsions with a dispersed phase made by flavor oil (20 wt%) + phytosterol (4 wt%) were stabilized with 3 wt% saponin were obtained by applying an ultrasonic time of 5 min and ultrasonic power of 280 W. The natural tea saponin emulsions exhibited a superior stability and encapsulation efficiency of phytosterol, compared to traditional emulsifiers. Flavor oil-phytosterol enriched powders were prepared by spray-drying and characterized by SEM, XRD and repose angle. The natural saponin encapsulated oil + phytosterol powders had excellent fluidity, redispersion behavior and low phytosterol crystallinity. It was demonstrated that ultrasound is an effective and suitable technique for fabricating fortified flavor emulsions and microcapsules, which may be used for developing functional lipids-based applications in the food, beverage and cosmetic industries.

Determination of singlet oxygen quenching rate and mechanism of γ-oryzanol

Photooxidation is one of the causes of quality deterioration in food. An antioxidant or singlet oxygen quencher is urgently needed to prevent photooxidation. γ-Oryzanol was recognized as a naturally present antioxidant in rice bran products. This research aimed to calculate the singlet oxygen quenching rate and its mechanism of γ-oryzanol to evaluate the potency of γ-oryzanol as singlet oxygen quencher. A series of linoleic acid (50 and 100 mM) or γ-oryzanol (0.7 and 1.5 mM) were prepared separately in ethanol: chloroform (96:4, v/v) containing 25 ppm of erythrosine. High-Performance Liquid Chromatography quantified the degradation of γ-oryzanol. Meanwhile, Gas Chromatography determined the changes in linoleic acid content during photooxidation. The singlet oxygen quenching rate was calculated by steady-state. The singlet oxygen quenching rate of γ-oryzanol was 3.04 × 106/M/s by physical and chemical quenching mechanism. Photooxidation caused the declined of γ-oryzanol by 0.1421 mM/h. Based on singlet oxygen quenching rate calculation, it suggests that γ-oryzanol can perform as a singlet oxygen quencher with slightly dominated by physical quenching mechanism (52.28%). The rest it performed via a chemical quenching mechanism.

Catalase to demulsify oil-in-water fish oil-polysorbate emulsion and affect lipid oxidation

The physicochemical and oxidative stability of oil emulsion has been one of the major challenges in food industry. Factors influencing the emulsion stability have seemingly been exhaustedly elucidated, such as temperature, pH, salts, proteins, polysaccharides and digestive enzymes. Here we report the previously unrecognized influence of catalase on emulsion stability. Submicron oil-in-water fish oil emulsion was prepared by high speed homogenization in the presence of polysorbate 80. Influence of catalase on the emulsion's stability was investigated in comparison with its deactivated version and bovine serum albumin (BSA) by visual examination, turbidity and DLS measurement and TEM observation. Catalase demulsified the emulsion instantly in a concentration-responsive manner at concentrations higher than 0.8 μmol/L, resulting a decreased turbidity, oil flocculation and precipitation of the enzyme itself. Neither BSA nor the thermally inactivated CAT caused demulsification at the same speed, indicating that CAT's demulsification effect was attributed to its enzymatic activity rather than its general protein properties. The enlargement of oil-polysorbate droplets and precipitation of CAT were confirmed by both TEM and DLS. Furthermore, CAT's demulsification effect was found irrelevant of the lipid oxidation. This insight into catalase's influences on emulsion not only sheds lights on food processing and shelf-life, nutritional value and potential biological effects, but also presents an exciting challenge to elucidate the mechanism behind.

The formation, stability of DHA/EPA nanoemulsion prepared by emulsion phase inversion method and its application in apple juice

This study prepared edible docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) nanoemulsion using EPI (emulsion phase inversion) method. The method for preparing DHA and EPA nanoemulsions is safe, convenient, low in energy consumption and can be used for food production. Factors affecting particle size and stability during preparation were investigated. Based on the optimal particle size combination, stability studies including particle size and residual rates of DHA and EPA at different temperature, pH and metal ions. The results showed that the nanoemulsion had good stability at low temperature storage, near neutral pH and in the absence of transition metal ions such as Fe³⁺, Cu²⁺, Al³⁺. The experiment initially studied the effect of nanoemulsion on apple juice beverage on the basic properties of juice itself. It was feasible in practical application of edible nanoemulsion.

Improving the Physical and Oxidative Stability of Emulsions Using Mixed Emulsifiers: Casein-Octenyl Succinic Anhydride Modified Starch Combinations

This study aims to investigate the influence of casein and octenyl succinic anhydride modified starch (OSAS) combinations on the physical and oxidative stability of fish oil-in-water emulsions. The interaction between casein and OSAS was manifested in changes in protein structure and hydrogen-bonding interaction. Casein-OSAS combinations could effectively inhibit droplet aggregation at pH 4 and attenuate droplet growth at a high CaCl2 concentration of 0.2 mol/L, compared with casein as an emulsifier. Nanoemulsions stabilized by casein-OSAS combinations or casein showed better oxidative stability compared with OSAS-stabilized emulsions. Therefore, casein-OSAS combinations can improve some physical properties of protein-based emulsions and oxidative stability of modified starch-based emulsions, suggesting protein-modified starch combinations are more promising in the emulsion-based food industry compared to each of the two emulsifiers alone.

Preparation and Evaluation of Release Formulation of γ-Oryzanol/Algae Oil Self-Emulsified with Alginate Beads

Self-emulsion improves solubility and bioavailability for γ-oryzanol/algae oil, and alginate beads can be used as controlled release carriers. In this study, self-emulsified alginate beads (SEABs) were prepared with different weight ratios of self-emulsion treatment (5%, 10%, 15%, 20%, and 30%) with alginate. We found that the microstructure with a surfactant of SEABs had a different appearance with alginate-based beads. The encapsulation of γ-oryzanol corresponded with the self-emulsion/alginate ratio, which was 98.93~60.20% with a different formulation of SEABs. During in vitro release, SEABs had the gastric protection of γ-oryzanol/algae oil, because γ-oryzanol and emulsion were not released in the simulated stomach fluid. When the SEABs were transferred to a simulation of the small intestine, they quickly began to swell and dissolve, releasing a higher content of the emulsion. We observed that the emulsion that formed had a bimodal distribution in the simulated intestinal fluid as a result of the hydrogel and emulsion droplets, leading to the formation of large aggregates. These results suggested that γ-oryzanol encapsulation within alginate beads via emulsification combined with gelation can serve as an effective controlled delivery system.

Microfluidization trends in the development of nanodelivery systems and applications in chronic disease treatments

Plant bioactive compounds are known for their extensive health benefits and therefore have been used for generations in traditional and modern medicine to improve the health of humans. Processing and storage instabilities of the plant bioactive compounds, however, limit their bioavailability and bioaccessibility and thus lead researchers in search of novel encapsulation systems with enhanced stability, bioavailability, and bioaccessibility of encapsulated plant bioactive compounds. Recently many varieties of encapsulation methods have been used; among them, microfluidization has emerged as a novel method used for the development of delivery systems including solid lipid nanocarriers, nanoemulsions, liposomes, and so on with enhanced stability and bioavailability of encapsulated plant bioactive compounds. Therefore, the nanodelivery systems developed using microfluidization techniques have received much attention from the medical industry for their ability to facilitate controlled delivery with enhanced health benefits in the treatment of various chronic diseases. Many researchers have focused on plant bioactive compound-based delivery systems using microfluidization to enhance the bioavailability and bioaccessibility of encapsulated bioactive compounds in the treatment of various chronic diseases. This review focuses on various nanodelivery systems developed using microfluidization techniques and applications in various chronic disease treatments.

Self-nanoemulsifying drug delivery system of bruceine D: a new approach for anti-ulcerative colitis

Background

Bruceine D (BD) is a major bioactive component isolated from the traditional Chinese medicinal plant Brucea javanica which has been widely utilized to treat dysentery (also known as ulcerative colitis [UC]).

Methods

To improve the water solubility and absolute bioavailability of BD, we developed a self-nanoemulsifying drug delivery system (SNEDDS) composing of MCT (oil), Solutol HS-15 (surfactant), propylene glycol (co-surfactant) and BD. The physicochemical properties and pharmacokinetics of BD-SNEDDS were characterized, and its anti-UC activity and potential mechanism were evaluated in TNBS-induced UC rat model.

Results

The prepared nanoemulsion has multiple beneficial aspects including small mean droplet size, low polydispersity index (PDI), high zeta potential (ZP) and excellent stability. Transmission electron microscopy showed that nanoemulsion droplets contained uniform shape and size of globules. Pharmacokinetic studies demonstrated that BD-SNEDDS exhibited enhanced pharmacokinetic parameters as compared with BD-suspension. Moreover, BD-SNEDDS significantly restored the colon length and body weight, reduced disease activity index (DAI) and colon pathology, decreased histological scores, diminished oxidative stress, and suppressed TLR4, MyD88, TRAF6, NF-κB p65 protein expressions in TNBS-induced UC rat model.

Conclusion

These results demonstrated that BD-SNEDDS exhibited highly improved oral bioavailability and advanced anti-UC efficacy. In conclusion, our current results provided a foundation for further research of BD-SNEDDS as a potential complementary therapeutic agent for UC treatment.

Improved Physicochemical Properties of Yogurt Fortified with Fish Oil/γ-Oryzanol by Nanoemulsion Technology

Fish oil has several dietary benefits, but its application in food formulations is limited because of its poor water-solubility, easy oxidation and strong odor. The purposes of this study were to produce a fish oil/γ-oryzanol nanoemulsion and to evaluate the effect of adding this nanoemulsion on the physicochemical and sensory characteristics of yogurts. Adding fish oil/γ-oryzanol nanoemulsion resulted in a significant reduction in the acidity and syneresis of yogurt. Yogurt with the nanoemulsion had significantly lower peroxide value (0.28 mmol/L after 21 days) and higher retention of eicosapentaenoic acid and docosahexaenoic acid contents (decreased to 95% and 94% of its initial value, respectively) than yogurt with fish oil/γ-oryzanol (peroxide value = 0.65 mmol/L; eicosapentaenoic acid and docosahexaenoic acid contents decreased to 72% and 53% of its initial value, respectively). Fish oil/γ-oryzanol nanoemulsion incorporated into yogurt had closer sensory attributes scores to plain yogurt. This study may have important implications for the application of fish oil/γ-oryzanol nanoemulsion in yogurt.