Influence of carrier oil type, particle size on in vitro lipid digestion and eugenol release in emulsion and nanoemulsions

Monoterpenoid synergy: a new frontier in biological applications

Monoterpenoids, compounds found in various organisms, have diverse applications in various industries. Their effectiveness is influenced by the oil's chemical composition, which in turn is influenced by plant genotype, environmental conditions, cultivation practices, and plant development stage. They are used in various industries due to their distinctive odor and taste, serving as ingredients, additives, insecticides, and repellents. These compounds have synergistic properties, resulting in superior combined effects over discrete ones, potentially beneficial for various health purposes. Many experimental studies have investigated their interactions with other ingredients and their antibacterial, insecticidal, antifungal, anticancer, anti-inflammatory, and antioxidant properties. This review discusses potential synergistic interactions between monoterpenoids and other compounds, their sources, and biological functions. It also emphasizes the urgent need for more research on their bioavailability and toxicity, underlining the importance and relevance of this comprehensive study in the current scientific landscape.

Controlling release of astaxanthin in β-sitosterol oleogel-based emulsions via different self-assembled mechanisms and composition of the oleogelators

In this study, three types of β-sitosterol-based oleogels (β-sitosterol + γ-oryzanol oleogels, β-sitosterol + lecithin, oleogels and β-sitosterol + monostearate oleogels), loaded with astaxanthin, were employed as the oil phase to create oleogel-based emulsions (SO, SL, and SM) using high-pressure homogenization. The microstructure revealed that fine-scale crystals were dispersed within the oil phase of the droplets in the β-sitosterol oleogel-based emulsion. The bioaccessibility of astaxanthin was found to be 58.13 %, 51.24 %, 36.57 %, and 45.72 % for SM, SL, SO, and the control group, respectively. Interestingly, the release of fatty acids was positively correlated with the availability of astaxanthin (P = 0.981). Further analysis of FFAs release and kinetics indicated that the structural strength of the oil-phase in the emulsions influenced the degree and rate of lipolysis. Additionally, the micellar fraction analysis suggested that the nature and composition of the oleogelators in SM and SL also impacted lipolysis and the bioaccessibility of astaxanthin. Furthermore, interfacial binding of lipase and isothermal titration calorimetry (ITC) measurements revealed that the oleogel network within the oil phase of the emulsion acted as a physical barrier, hindering the interaction between lipase and lipid. Overall, β-sitosterol oleogel-based emulsions offer a versatile platform for delivering hydrophobic molecules, enhancing the bioavailability of active compounds, and achieving sustained release.

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

Antarctic krill oil (AKO) is highly sought after by consumers and the food industry due to its richness in a variety of nutrients and physiological activities. However, current extraction methods are not sufficient to better extract AKO and its nutrients, and AKO is susceptible to lipid oxidation during processing and storage, leading to nutrient loss and the formation of off-flavors and toxic compounds. The development of various extraction methods and encapsulation systems for AKO to improve oil yield, nutritional value, antioxidant capacity, and bioavailability has become a research hotspot. This review summarizes the research progress of AKO from extraction to encapsulation system construction. The AKO extraction mechanism, technical parameters, oil yield and composition of solvent extraction, aqueous enzymatic extraction, supercritical/subcritical extraction, and three-liquid-phase salting-out extraction system are described in detail. The principles, choice of emulsifier/wall materials, preparation methods, advantages and disadvantages of four common encapsulation systems for AKO, namely micro/nanoemulsions, microcapsules, liposomes and nanostructured lipid carriers, are summarized. These four encapsulation systems are characterized by high encapsulation efficiency, low production cost, high bioavailability and high antioxidant capacity. Depending on the unique advantages and conditions of different encapsulation methods, as well as consumer demand for health and nutrition, different products can be developed. However, existing AKO encapsulation systems lack relevant studies on digestive absorption and targeted release, and the single product category of commercially available products limits consumer choice. In conjunction with clinical studies of AKO encapsulation systems, the development of encapsulation systems for special populations should be a future research direction.

Recent insights into Nanoemulsions: Their preparation, properties and applications

The ever-increasing demand for healthy diet by consumers has prompted the research adopting cutting-edge methods that can maintain the quality of fruits and vegetables without the use of preservatives. Emulsion based coating approach has been regarded as a viable way to extend the shelf life of fresh produce. New opportunities are being created in a number of industries, (medicines, cosmetics and food) because of new advancements in the developing field of nanoemulsions. Nanoemulsion based methods are efficient for encapsulating the active ingredients including antioxidants, lipids, vitamins and antimicrobial agents owing to the small droplet size, stability and improved biological activity. This review provides an overview of recent developments in preserving the quality and safety of fresh-cut fruits & vegetables with nanoemulsion as a carrier of functional compounds (antimicrobial agents, antibrowning/antioxidants and texture enhancers). In addition, material and methods used for fabrication of the nanoemulsion is also described in this review. In addition, material and methods used for fabrication, of the nanoemulsion is also present.

Fabrication and Characterization of Novel Food-Grade Bigels Based on Interfacial and Bulk Stabilization

Novel food-grade bigels were fabricated using zein nanoparticles for interfacial stabilization and non-surfactant gelators (beeswax and tapioca) for bulk stabilization. The present study demonstrated the importance of interfacial stability for biphasic gels and sheds light on the roles of the gelation mechanism and the oil/water ratio of a bigel on its microstructure, physical properties, and digestion behaviors. The results indicated that it is not an easy task to realize homogenization and subsequent gelation in beeswax-tapioca biphasic systems, as no amphiphilic components existed. However, applying the binding of zein nanoparticles at the oil-water interface allowed us to produce a homogeneous and stable bigel (oil fraction reach 40%), which exhibited enhanced structural and functional properties. Oleogel structures play a crucial role in determining the deformation response of bigel systems. As the oil content increased, the mechanical strength and elastic properties of bigels were enhanced. In the meantime, clear bigel-type transitions were observed. In addition, the fabricated bigels were shown to be beneficial for delayed digestion, and the lowest degree of lipolysis could be found in bigel with 50% oleogel.

Impact of Grape Seed Powder and Black Tea Brew on Lipid Digestion-An In Vitro Co-Digestion Study with Real Foods

Effects of two foods with bioactive constituents (black tea brew, BTB and grape seed powder, GSP) on lipid digestibility was studied. Lipolysis inhibitory effect of these foods was examined using two test foods (cream and baked beef) with highly different fatty acid (FA) composition. Digestion simulations were performed either using both gastric and pancreatic lipase, or only with pancreatic lipase according to the Infogest protocol. Lipid digestibility was assessed based on the bioaccessible FAs. Results showed the triacylglycerols containing short- and medium-chain FAs (SCFA and MCFA) are non-preferred substrates for pancreatic lipase; however, this is not characteristic for GL. Our findings suggest that both GSP and BTB primarily affect the lipolysis of SCFAs and MCFAs, because the dispreference of pancreatic lipase towards these substrates was further enhanced as a result of co-digestion. Interestingly, GSP and BTB similarly resulted in significant decrease in lipolysis for cream (containing milk fat having a diverse FA profile), whereas they were ineffective in influencing the digestion of beef fat, having simpler FA profile. It highlights that the characteristics of the dietary fat source of a meal can be a key determinant on the observed extent of lipolysis when co-digested with foods with bioactive constituents.

Cold plasma treatment with alginate oligosaccharide improves the digestive stability and bioavailability of nutrient-delivered particles: An in vitro INFOGEST gastrointestinal study

To improve the stability and bioavailability of the delivered hydrophobic nutrients, the zein-based delivery system was modified by alginate oligosaccharide (AOS), cold plasma (CP) treatments, and synergistically. The digestive behavior of each was investigated in an INFOGEST static in vitro digestion model. The results showed that AOS and CP treatments and their synergistic effects improved the dispersion and stability of the delivery system, leading to a more concentrated particle size distribution and higher particle surface charge. Both CP treatments and AOS increased the release rate of Curcumin (Cur) at small intestine (11.8 % to 20.5 % and 11.8 % to 24.64 %, respectively), and the synergistic effect was higher (11.8 % to 43.84 %). The wall material modified showed a higher encapsulation efficiency of Cur (52.83 % to 85.17 %). Cur release rate measurements showed that the wall material modified could have a positive effect on the slow release of Cur. SDS-page electrophoresis revealed that the slow release was due to the enhanced resistance of wall material to digestive fluids. Thus, treatment with AOS and CP treatments, and the synergism are suitable for modifying zein-based delivery systems for the encapsulation, stabilization, and slow release of hydrophobic nutrients during digestion in the field of functional foods.

Digestion behavior, in vitro and in vivo bioavailability of cannabidiol in emulsions stabilized by whey protein-maltodextrin conjugate: Impact of carrier oil

An emulsion delivery system may be affected significantly by oil phase composition in terms of digestion behavior and bioavailability of the delivered substance. In this study, emulsions loaded with cannabidiol (CBD) were prepared with medium chain triglyceride (MCT), long chain triglyceride (LCT) or MCT/LCT(1:1) as carrier oil and whey protein-maltodextrin conjugate as emulsifier, and the digestion behavior of emulsion and bioavailability of CBD were assessed in vitro and in vivo. The particle size of emulsions throughout the in vitro digestion process was in the order of MCT < MCT/LCT < LCT, and three emulsions showed consistent particle size changes: stable in oral phase, sharply increased in gastric phase, and decreased in small intestine. After intestinal digestion, about 90% of free fatty acids (FFA) was released in MCT emulsion, followed by MCT/LCT (76%) and then LCT (45%). CBD was degraded during gastrointestinal digestion and the transformation stability of CBD in oil phase was in the order of LCT > MCT/LCT > MCT. Although CBD had higher bioaccessibility in MCT and MCT/LCT emulsions, the bioavailability of CBD in LCT was the highest (43%), followed by MCT/LCT (39%), MCT (33%). In vivo pharmacokinetic study showed that MCT/LCT and LCT were more favorable for CBD transport and absorption. The results may provide useful information for the construction of delivery systems, protecting CBD molecules, and improving their bioavailability.

Natural carriers: Recent advances in their use to improve the stability and bioaccessibility of food active compounds

In the last decades, the incorporation of bioactive compounds in food supplements aroused the attention of scientists. However, these ingredients often exhibit both low solubility and stability and their poor bioaccessibility within the gastrointestinal tract limits their effectiveness. To overcome these drawbacks, many carriers have been investigated for encapsulating nutraceuticals and enhancing their bioavailability. It is note that several different vegetable wall materials have been applied to build delivery systems. Considering their encapsulation mechanism, lipid and protein-based carriers display specific interaction patterns with bioactives, whereas polysaccharidic-based carriers can entrap them by creating porous highly stable networks. To maximize the encapsulation efficiency, mixed systems are very promising. Following the current goal of using natural and sustainable ingredients, only a limited number of studies about the isolation of new ingredients from agro-food waste are available. In this review, a comprehensive overview of the state of art in the development of innovative natural lipid-, protein- and polysaccharide-based plant carriers is presented, focusing on their application as food active compounds. Different aspects to be considered in the design of delivery systems are discussed, including the carrier structure and chemical features, the interaction between the encapsulating and the core material, and the parameters affecting bioactives entrapment.

Fabrication and characterization of β-carotene emulsions stabilized by soy oleosin and lecithin mixtures with a composition mimicking natural soy oleosomes

Natural soy oleosomes are known to have a remarkable stability, given the advantage of their sophisticated membrane. The aim of the present study is to examine the concept of fabricating a β-carotene emulsion stabilized by soy oleosin (OLE) and lecithin (LEC) mixtures mimicking the membrane composition of soy oleosomes while providing preferable stability and bioaccessibility. For this, the fabricated emulsion was characterized in terms of droplet size distribution, and emulsion structure, stability and digestion (release and absorption of lipophilic β-carotene). Compared to SPI/LEC (10 : 1) stabilized emulsions, the OLE/LEC (10 : 1) mixture stabilized emulsion exhibited the highest emulsifying activity index (EAI) and emulsifying stability index (ESI) values, and higher encapsulation efficiency. Results show that the β-carotene emulsion stabilized by OLE and LEC mixtures at the ratio of 10 : 1 (w/w) has the most uniform droplet distribution and highest stability. The in vitro gastrointestinal digestion test revealed that the β-carotene emulsion stabilized by OLE and LEC mixtures was digested more rapidly than the emulsion stabilized by soy protein isolate (SPI) and LEC mixtures. In turn, the bioaccessibility and cellular uptake of β-carotene were enhanced, resulting in a higher absorption, a desirable feature of nutrition delivery systems. Our results demonstrated a promising way to fabricate emulsions mimicking natural soy oleosomes.

Nanoemulsions for Enhancement of Curcumin Bioavailability and Their Safety Evaluation: Effect of Emulsifier Type

This work aimed at evaluating the effects of different emulsifiers on curcumin-loaded nanoemulsions’ behavior during digestion, its safety and absorption, to develop nanoemulsions that provide safety and improved curcumin functionality. Nanoemulsions (NEs) were produced using two bio-based (lecithin (LEC) and rhamnolipids (RHAM)) and one synthetic (Tween^®80 (TWE)) emulsifier at similar concentrations. Different NEs were subjected to in vitro digestion. The cytotoxicity and permeability tests were performed in Caco-2 cells. NE_TWE were stable during all phases of in vitro digestion, whereas NE_LEC and NE_RHAM were found to be unstable from the gastric phase. NE_TWE showed 100% of free fatty acids released, followed by NE_RHAM and NE_LEC. Curcumin’s bioaccessibility and stability increased in the following order: NE_LEC > NE_RHAM > NE_TWE. NE_LEC and NE_TWE did not show cytotoxic effects in any of the concentrations tested, while NE_RHAM presented high cytotoxicity in all concentrations tested. The apparent permeability coefficients were determined for NE_LEC and NE_TWE; however, the results were not statistically different. These results showed that the emulsifier used has a high impact on nanoemulsions’ behavior under the digestion process and on their cytotoxicity. This work contributed to the state-of-the-art’s progress on the development of safer curcumin delivery systems with improved functionality, particularly regarding the proper selection of ingredients to produce said systems.

Influence of oil matrixes on stability, antioxidant activity, bioaccessibility and bioavailability of astaxanthin ester

BACKGROUND

Astaxanthin ester (Asta-E) is used as functional nutraceuticals in many food products. Unfortunately, Asta-E utilization is currently limited owing to its chemical instability and low bioavailability. The purpose of this study is to investigate the promotion effect of oil matrixes on the stability, antioxidant activity, bioaccessibility and bioavailability of Asta-E.

RESULTS

The results showed that the stability of Asta-E in six oil matrixes was improved. Based on the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity experiment, the antioxidant activity of Asta-E was positively correlated with the degree of unsaturation of the oil matrixes, but not with the side chain length. The in vitro gastrointestinal tract (GIT) simulation model and in vivo experiment using mice were also employed to investigate the digestion and absorption characteristics of Asta-E in various oil matrixes. The results demonstrated that the bioaccessibility and bioavailability of Asta-E increased with the increase of fatty acid chain length of oil matrixes (triglyceride oleate > triglyceride caprylate > triglyceride butyrate), as well as with the decrease of unsaturation degree (olive oil > corn oil > fish oil).

CONCLUSION

Monounsaturated fatty acids (MUFA) and long-chain triglyceride (LCT) in an oil matrix were the factors that could efficiently improve the bioavailability of Asta-E. Moreover, the size of the mixed micelles of Asta-E during digestion was the main factor influencing the bioaccessibility of Asta-E. This study provides references for the design of suitable oil matrixes for Asta-E. © 2020 Society of Chemical Industry.

Lecithin alleviates protein flocculation and enhances fat digestion in a model of infant formula emulsion

This study investigates whether lecithin could fasten lipolysis through the alleviation of protein aggregation in an infant formula emulsion model. Our previous study reported low intestinal digestion of infant formula could be due to the aggregation of proteins that slow lipid digestion. The emulsion contained lipids droplets simulating the fatty acid composition in breast milk, different levels of lecithin and milk protein. The interphase proteins were replaced with lecithin in a dose-dependent manner. The results showed the addition of 5% and 7% lecithin improves the physical stability, narrows the range of particle size, reduces the mean particle size and increases the zeta potential. The 5% lecithin emulsion showed the highest rate and extent of lipid and protein digestion. These positive effects were caused by lecithin through stabilizing the emulsion and suppressing droplet flocculation after digestion. Lecithin promotes lipid digestion and may improve the "insufficient fat supply" in infant formula.

Vitamin D3 bioaccessibility: Influence of fatty acid chain length, salt concentration and l-α-phosphatidylcholine concentration on mixed micelle formation and delivery of vitamin D3

Vitamin D (VD) is a fat-soluble vitamin with high deficiency levels evident globally. Bioaccessibility of VD is influenced by formation of mixed micelles (MM) during digestion. This study assessed the impact of fatty acid (FA) type, phospholipid concentration on MM formation and stability of MM to salts. MM formation occurred at NaCl and KCl concentrations ranging from 20 to 100 mM, when octanoic acid (C8) or stearic acid (C18) were used. MM hydrodynamic size increased with increasing l-α-phosphatidylcholine concentration (1.5-7.5 mM) for both C8 and C18, above which concentration MM did not form. FA chain length impacted MM with hydrodynamic size increasing from 3.8 nm for decanoic acid (C10) to 4.4 nm for C18. VD₃ incorporation in MM was not influenced by the FA used (C10 or C18). Understanding stability and formation of MM and VD₃ loading is an essential first step towards manipulating food structures for improving delivery of VD.

Influence of the particle size and hydrocolloid type on lipid digestion of thickened emulsions

Hydrocolloids are used as stabilizing agents in order to enhance the physical stability of emulsions during their storage. However, they can also play an important role in nutrient release and bioavailability. In this context, the aim of this research was to study the effect of the emulsion type and thickener type on the physical-structural changes and free fatty acid release during in vitro digestion. Oil-in-water emulsions were prepared with different particle sizes (CE: conventional emulsions and NE: nanoemulsions) and thickening agents (starch and xanthan gum). The experimental conditions of homogenization used allowed food emulsions to be obtained at the microscale and nanoscale, with particle sizes ranging among 3.2-3.4 μm and 78-107 nm for CE and NE, respectively. The addition of thickening agents (XG and ST) modified the physical properties of emulsions (particle size, zeta potential and stability) slightly, and thickened samples with similar viscosity were obtained. The kinetics of FFAs released during the in vitro intestinal digestion showed no significant differences (p > 0.05) in the digestion rate among samples; however, emulsion and thickener types decreased the final extent of free fatty acids, being more evident for those samples with starch. Xanthan gum kept the particle size of nanoemulsions stable during the oral and gastric phases, which promoted the release of FFAs during the intestinal phase. Therefore, xanthan gum could be used as a thickening agent of nanoemulsions exerting a minor impact on their lipid bioaccessibility.

Natural Macromolecules as Carriers for Essential Oils: From Extraction to Biomedical Application

Essential oils (EOs) and their main constituents, the terpenes, are widely studied, mostly relating to their antioxidant ability and bioactivity, such as antimicrobial, anticancer, anti-inflammatory, and range of other actions in the living systems. However, there is limited information on their bioavailability, especially upon clinical studies. Having in mind both strong biological effects and health benefits of EOs and their specific physicochemical properties (volatility, lipophilic character, low water solubility or insolubility, viscosity, expressed odor, concentration-dependent toxicity, etc.), there is a need for their encapsulation for target delivery. Encapsulation of EOs and their constituents is the prerequisite for enhancing their oxidative stability, thermostability, photostability, shelf life, and biological activity. We considered various carrier types such a (1) monophase and polyphase polysaccharide hydrogel carriers, (2) polysaccharide-protein carriers, and (3) lipid carriers in the context of physicochemical and engineering factors. Physicochemical factors are encapsulation efficiency, chemical stability under gastric conditions, mechanical stability, and thermal stability of carrier matrices. Choice of carrier material also determines the encapsulation technique. Consequently, the engineering factors are related to the advantage and disadvantage of various encapsulation techniques frequently used in the literature. In addition, it was intended to address the interactions between (1) main carrier components, such as polysaccharides, proteins, and lipids themselves (in order to form chemically and mechanically stable structure); (2) main carrier components with pepsin under gastric conditions (in order to form resistant material under gastric conditions); and (3) main carrier components with EOs (in order to enhance encapsulation efficiency), as a necessary precondition for whole process optimization. Finally, different sources for obtaining natural carrier macromolecules are surveyed, especially the agro-waste materials and agricultural and food by-products. This review article highlights the bioavailability aspects of encapsulated EOs and physicochemical and engineering factors concerning natural macromolecule carriers for their target delivery and application.

Effects of Chemical Composition and Microstructure in Human Milk and Infant Formulas on Lipid Digestion

Infant formula (IF) is an important substitute for infants when human milk (HM) is unavailable; however, it was often observed with "insufficient fat" and showed different metabolic phenotypes, which may affect the growth and brain development of the infant. Considering that the milk fat digestion rate may affect the fat absorption and metabolism and further influence the metabolic phenotype, it is valuable to study the fat digestive behaviors of IF and HM. In the current study, we investigated the in vitro fat digestive properties of HM in comparison to four formulas (IF1, 2, 3, 4) including IFs enriched in OPO lipids (IF1 and IF3) and IFs with common mixed plant oils (IF2 and IF4). Results showed that the extent of eventual lipid hydrolysis of HM (98.9 ± 2.70%) was higher than those of IF1 and IF3 (90.4 ± 3.39 and 91.1 ± 1.67%, respectively) (p < 0.05) and IF2 and IF4 (81.9 ± 1.64 and 79.9 ± 1.05% respectively) (p < 0.01). Native fat globules and protein aggregation were observed at the end of HM gastric digestion, and the aggregates became smaller and then resolved from 60 to 120 min in intestinal digestion, while a large number of aggregates were observed in IF, which may slow the lipid digestion. The absorption differences between HM and IFs in lipid digestion need further study to elucidate the nutritional relevance to infant development and growth.

Aqueous ethyl acetate as a novel solvent for the degreasing of black soldier fly (Hermetia illucens L.) larvae: degreasing rate, nutritional value evaluation of the degreased meal, and thermal properties

BACKGROUND

The aim of this study was to select appropriate low-toxicity degreasing solvents to degrease black soldier fly (BSF, Hermetia illucens L.) larvae to prepare high-quality protein. Aqueous ethyl acetate was chosen as the solvent to extract BSF protein, and traditional solvents, such as petroleum ether, n-hexane, and isopropanol, were chosen as controls.

RESULTS

The meal degreased by aqueous ethyl acetate (the volume ratio of ethyl acetate to water is 90 to 10, EA + W10) shows a high degreasing rate (29.04%), crude protein content (562.3 g kg^-1 ), essential amino acid index (EAAI, 95.57), and digestible indispensable amino acid score (DIAAS, 85). The digestibility of the degreased meal samples in the simulated in vitro intestine can reach 76.52%. Thermodynamic analysis and the apparent morphology of the protein fragments showed that the meal degreased by EA + W10 exhibited thermodynamic stability, which suggests that using aqueous ethyl acetate as the degreasing solvent did not affect the nutritional value of the degreased meal.

CONCLUSION

The results suggest that aqueous ethyl acetate (EA + W10) can be used as a novel solvent in the degreasing of BSF larvae meal to prepare high-quality protein with high EAAI and DIAAS and good digestibility. © 2019 Society of Chemical Industry.

Physicochemical characterization and antimicrobial activity in novel systems containing buriti oil and structured lipids nanoemulsions

Buriti oil nanoemulsions were prepared using non-interesterified buriti oil or buriti oil interesterified for 6 or 24 h (NBO, NBO6h, and NBO24 h), respectively. The aim was to investigate the effects of interesterified oils on the physicochemical and biological properties of nanoemulsions. Samples were stored at 4 and 25 °C for 30 days, and their physicochemical properties and biological activities were evaluated. The mean droplet diameter of nanoemulsions ranged from 196 to 270 nm. NBO24 h had the smallest droplet size and was the most stable during the storage period. Furthermore, NBO24 h demonstrating the good oxidative stability, had a high antioxidant capacity, and was less susceptible to droplet aggregation. NBO and NBO24 h had similar biological activity against Gram-negative bacteria (Escherichia coli O157: H7); bacterial growth was inhibited by at least 60% at 3.12 mg mL-1. The nanoemulsions have interesting properties for the production of pharmaceutical, cosmetic, and food formulations with antimicrobial activity.

Bioaccessibility of Lipophilic Compounds Vehiculated in Emulsions: Choice of Lipids and Emulsifiers

Great efforts have been made to design emulsions considering the need to perform an effective encapsulation, protection, vehiculation, and bioaccessibility of lipophilic compounds. This task can be achieved by manipulating the structure of the emulsion based on the choice of the processes and ingredients of the aqueous phase, interface, and lipid matrix. Thus, the main focus of this perspective is to provide insights into the use of ingredient engineering in manipulating/building emulsion structures that enhance lipophilic compound release and bioaccessibility.

Encapsulation of pterostilbene in nanoemulsions: influence of lipid composition on physical stability, in vitro digestion, bioaccessibility, and Caco-2 cell monolayer permeability

Nanoemulsions fabricated using medium chain triglycerides as carrier lipid are more effective for delivering pterostilbene than long chain triglycerides.

A systematic review on nanoencapsulation of food bioactive ingredients and nutraceuticals by various nanocarriers

Today, there is an ever-growing interest on natural food ingredients both by consumers and producers in the food industry. In fact, people are looking for those products in the market which are free from artificial and synthetic additives and can promote their health. These food bioactive ingredients should be formulated in such a way that protects them against harsh process and environmental conditions and safely could be delivered to the target organs and cells. Nanoencapsulation is a perfect strategy for this situation and there have been many studies in recent years for nanoencapsulation of food components and nutraceuticals by different technologies. In this review paper, our main goal is firstly to have an overview of nanoencapsulation techniques applicable to food ingredients in a systematic classification, i.e., lipid-based nanocarriers, nature-inspired nanocarriers, special-equipment-based nanocarriers, biopolymer nanocarriers, and other miscellaneous nanocarriers. Then, application of these cutting-edge nanocarriers for different nutraceuticals including phenolic compounds and antioxidants, natural food colorants, antimicrobial agents and essential oils, vitamins, minerals, flavors, fish oils and essential fatty acids will be discussed along with presenting some examples in each field.

Stability and in vitro digestibility of beta-carotene in nanoemulsions fabricated with different carrier oils

Beta-carotene, the main dietary source of provitamin A, is required for maintaining optimum human health. The bioaccessibility of beta-carotene can be greatly improved when ingested with fat. Therefore, the aim of the current study was to select proper oils (palm oil, coconut oil, fish oil, and corn oil) as a carrier to form stable nanoemulsion that can effectively enhance the bioaccessibility of beta-carotene. The nanoemulsion was formulated with 90% (v/v) aqueous solution (2% whey protein isolate, WPI, w/v) and 10% (v/v) dispersed oil. The in vitro digestion experiment of nanoemulsions showed that the bioaccessibility of beta-carotene was as followed in order: palm oil = corn oil > fish oil > coconut oil (p < 0.05). The particle size of the nanoemulsion (initial particle size = 168-185 nm) was below 200 nm during 42 days' storage at 25°C. The retention rates of beta-carotene in nanoemulsions were 69.36%, 63.81%, 49.58%, and 54.91% with palm oil, coconut oil, fish oil, and corn oil, respectively. However, the particle size of the nanoemulsion increased significantly in the accelerated experiment at 55°C (p < 0.05), in which the retention rates of beta-carotene were 48.56%, 43.41%, 29.35%, and 33.60% with palm oil, coconut oil, fish oil, and corn oil, respectively. From above, we conclude that WPI-stabilized beta-carotene nanoemulsion with palm oil as the carrier is the most suitable system to increase bioaccessibility and stability of lipid-soluble bioactive compounds such as beta-carotene.

Effect of Emulsifier Concentration and Physical State on the In Vitro Digestion Behavior of Oil-in-Water Emulsions

The influence of emulsifier physical state and concentration on the in vitro digestion of oil-in-water (O/W) emulsions was investigated. Two citrated monoacylglycerols, glyceryl stearate citrate (GSC, bulk mp of 55-65 °C) and glyceryl oleate citrate (GOC, bulk mp of 0-10 °C), were used at 0.5 or 5 wt % of the emulsions to generate 20 wt % soybean oil O/W emulsions. Oil droplet lipolysis was slower in emulsions with 0.5 wt % emulsifier versus in those with 5 wt % emulsifier, resulting from the reduced surface-to-volume ratio in emulsions at 0.5 wt % emulsifier and the increased concentration of hydrolyzable groups at 5 wt % emulsifier. When excluding gastric digestion, all emulsions were similarly digested, confirming that emulsion intestinal digestion was highly dependent on gastric preprocessing. Finally, at a given emulsifier concentration, GSC-based emulsions with an interfacial crystalline shell experienced a decreased rate of intestinal lipid digestion compared with their GOC-based counterparts, confirming that emulsifier physical state played a role in lipid digestion.

Essential Oils as Feed Additives-Future Perspectives

The inconsistency of phytogenic feed additives' (PFA) effects on the livestock industry poses a risk for their use as a replacement for antibiotic growth promoters. The livestock market is being encouraged to use natural growth promotors, but information is limited about the PFA mode of action. The aim of this paper is to present the complexity of compounds present in essential oils (EOs) and factors that influence biological effects of PFA. In this paper, we highlight various controls and optimization parameters that influence the processes for the standardization of these products. The chemical composition of EOs depends on plant genetics, growth conditions, development stage at harvest, and processes of extracting active compounds. Their biological effects are further influenced by the interaction of phytochemicals and their bioavailability in the gastrointestinal tract of animals. PFA effects on animal health and production are also complex due to various EO antibiotic, antioxidant, anti-quorum sensing, anti-inflammatory, and digestive fluids stimulating activities. Research must focus on reliable methods to identify and control the quality and effects of EOs. In this study, we focused on available microencapsulation techniques of EOs to increase the bioavailability of active compounds, as well as their application in the animal feed additive industry.

Triglyceride Structure Modulates Gastrointestinal Digestion Fates of Lipids: A Comparative Study between Typical Edible Oils and Triglycerides Using Fully Designed in Vitro Digestion Model

Three typical edible oils (palm oil, PO; leaf lard oil, LO; rapeseed oil, RO) and triacylglycerols (TAGs) (glycerol tripalmitate, GTP; glycerol tristearate, GTS; glycerol trioleate, GTO) were selected to conduct digestion experiments using fully designed in vitro digestion model. The evolutions in mean particle diameter, ζ-potential, and microstructural changes during different digestion stages were investigated. Free fatty acid (FFA) release extent and kinetics were monitored by pH-Stat method. The particle characterization of different lipids during passage through the GIT depended on lipid type and the microenvironment they encountered. Absorbed surface protein can hardly be the obstacle for pancreas lipase to catalyze lipid hydrolysis after gastric digestion. The maximum FFA release level and apparent rate constant in small intestine digestion stage of the three oils and TAGs were: PO > RO > LO, GTP > GTS > GTO, respectively. PO showed the highest FFA release level and rate mainly due to the short chain length saturated palmitic acid (C16:0) specifically located in the Sn-1, 3 positions of TAG molecules in palm oil, while the Sn-1, 3 positions of TAG molecules in RO and LO were mainly mono- or polyunsaturated fatty acids (C18:1 or C18:2), restricting the continuous hydrolysis reaction. These findings can provide some basic understanding of the digestion differences of different lipids, which may be useful for their nutritional and functional evaluation and the applicability in the food area.

Micro- and nano bio-based delivery systems for food applications: In vitro behavior

Micro- and nanoencapsulation is an emerging technology in the food field that potentially allows the improvement of food quality and human health. Bio-based delivery systems of bioactive compounds have a wide variety of morphologies that influence their stability and functional performance. The incorporation of bioactive compounds in food products using micro- and nano-delivery systems may offer extra health benefits, beyond basic nutrition, once their encapsulation may provide protection against undesired environmental conditions (e.g., heat, light and oxygen) along the food chain (including processing and storage), thus improving their bioavailability, while enabling their controlled release and target delivery. This review provides an overview of the bio-based materials currently used for encapsulation of bioactive compounds intended for food applications, as well as the main production techniques employed in the development of micro- and nanosystems. The behavior of such systems and of bioactive compounds entrapped into, throughout in vitro gastrointestinal systems, is also tracked in a critical manner. Comparisons between various in vitro digestion systems (including the main advantages and disadvantages) currently in use, as well as correlations between the behavior of micro- and nanosystems studied through in vitro and in vivo systems were highlighted and discussed here for the first time. Finally, examples of bioactive micro- and nanosystems added to food simulants or to real food matrices are provided, together with a revision of the main challenges for their safe commercialization, the regulatory issues involved and the main legislation aspects.

Antimicrobial activity of eugenol and essential oils containing eugenol: A mechanistic viewpoint

Eugenol is a hydroxyphenyl propene, naturally occurring in the essential oils of several plants belonging to the Lamiaceae, Lauraceae, Myrtaceae, and Myristicaceae families. It is one of the major constituents of clove (Syzygium aromaticum (L.) Merr. & L.M. Perry, Myrtaceae) oil and is largely used in both foods and cosmetics as a flavoring agent. A large body of recent scientific evidence supports claims from traditional medicine that eugenol exerts beneficial effects on human health. These effects are mainly associated with antioxidant and anti-inflammatory activities. Eugenol has also shown excellent antimicrobial activity in studies, being active against fungi and a wide range of gram-negative and gram-positive bacteria. The aim of this review is to analyze scientific data from the main published studies describing the antibacterial and antifungal activities of eugenol targeting different kind of microorganisms, such as those responsible for human infectious diseases, diseases of the oral cavity, and food-borne pathogens. This article also reports the effects of eugenol on multi-drug resistant microorganisms. On the basis of this collected data, eugenol represents a very interesting bioactive compound with broad spectrum antimicrobial activity against both planktonic and sessile cells belonging to food-decaying microorganisms and human pathogens.