An overview of microencapsulation in the food industry: opportunities, challenges, and innovations

Microencapsulation of sacha inchi oil using tannic acid, yeast cells and xanthan gum as wall materials

This study investigated the encapsulation of sacha inchi oil using complex coacervation of recovered yeast cells and xanthan gum via double emulsion. Turbidimetric analysis revealed interactions between yeast cells (YC) and tannic acid (TA), which increased turbidity to a 1:3 YC:XG ratio suggesting that TA could be a promising crosslinking agent for enhancing coacervation. Optimal encapsulation efficiency was achieved at a core-to-wall ratio of 1:1 in a core solution concentration of 1 % relative to the total polymer concentration. Under these conditions, the microparticles exhibited an average particle size of 72.44 ± 1.83 μm, with low water activity and water solubility. Morphological analysis suggests that the microcapsules showed a heterogeneous structure formed by different layers of wall material, potentially making them suitable for use in food matrices. The use of TA to form TA-YC:XG microcapsules improved the oxidative stability (39.84 ± 0.43 meqO2/kg of peroxide value after six simulated months) of the microcapsules and slowed down oil release (approximately 20 % in simulated gastric fluid) during the in vitro digestion test. These finds highlight the potential of microencapsulation using recovered yeast cells as a strategy to enhance encapsulation efficiency and protect against oxidation and digestion challenges. This approach opens new possibilities for the use of sacha inchi oil as a food ingredient.

Challenges and Advances in the Encapsulation of Bioactive Ingredients Using Whey Proteins

Functional foods represent an emerging trend in the food industry. Fortifying foods with bioactive ingredients results in health benefits and reduces the risk of disease. Encapsulation techniques protect sensitive ingredients from degradation due to heat, light, moisture and other factors. Among encapsulating materials, milk whey proteins are particularly attractive due to their availability, GRAS status and remarkable ligand-binding ability. Whey protein was once considered a by-product in the dairy industry but is now seen as a promising resource given its natural role as a nutrient carrier. This work reviews the encapsulation systems that employ whey proteins in the food industry. The structural features of β-lactoglobulin (β-LG), the main protein constituent of milk whey, are presented in the context of its ligand-binding properties. Different types of encapsulation systems using whey proteins are discussed, focusing on the recent advances in stable formulations of bioactives using whey protein, alone or in hybrid systems. Whey proteins are a valuable asset capable of binding sensitive bioactive compounds such as vitamins, polyphenols and antioxidants and forming stable complexes that can be formulated as nanoparticles, nanofibrils, emulsions and other micro- and nanostructures. Developing scalable, solid and stable encapsulation systems is identified as a main challenge in the field.

Enhancing the stability and functionality of phycobiliproteins as natural food colourants through microparticle formulation

The food industry is increasingly turning to microalgae pigments as natural functional colourants to replace potentially harmful synthetic dyes. Among those, phycobiliproteins offer deep and vibrant colours with bioactivities, showing to be a promising alternative. However, incorporating them into a food matrix can be challenging due to their inherent instability, low bioavailability, and off-flavours. Accordingly, the present work aimed to prepare microparticles of phycocyanin (PCMP) and of an ultrasound-assisted phycoerythrin-rich extract from Porphyridium purpureum (PEMP) to improve these natural colourants' stability and functional properties. The microparticles were prepared by Nano spray-drying using inulin and gum Arabic as coating materials, resulting in particles with high yield, encapsulation efficiency (from 69 % to 80 %), solubility, and colour retention. Combining inulin and gum Arabic allowed the formation of smaller and more homogeneous particles with increased antioxidant potential when compared to using inulin alone. Moreover, gum Arabic improved the bioaccessibility of PEMP from 35 % to 51 %, demonstrating the potential of this microparticle formulation to enhance the stability and functionality of phycobiliproteins.

Horseradish (Armoracia rusticana L.) leaf juice encapsulated within polysaccharides-blend-based carriers: Characterization and application as potential antioxidants in mayonnaise production

This study aimed to encapsulate cold-pressed horseradish leaf juice within maltodextrin/alginate (MD/AL), maltodextrin/guar gum (MD/GG), and maltodextrin/gum Arabic (MD/GA) by spray-drying, to characterize the encapsulates, and to test their potential as mayonnaise oxidation-preventing ingredients. The encapsulates exhibited desirable physicochemical, morphological, structural, and thermal properties, highlighting MD/GA-containing encapsulates, especially regarding high encapsulation yield (78.50 %). Also, encapsulates contained a significant amount of phenolics, which were stable during freezer storage. The encapsulates successfully delayed the mayonnaise oxidation: 31.91-38.94 % more than the synthetic antioxidant ethylenediaminetetraacetic acid, especially highlighting MD/AL-containing encapsulates. Also, the encapsulates improved product quality with a higher pH and lower acidity after storage compared to the controls. Overall acceptability of encapsulates-containing mayonnaises and commercial mayonnaise did not differ significantly. This study contributes to sustainable development by providing new insights into the valorization of horseradish leaves, as a promising alternative to synthetic additives to prolong the oxidative stability and shelf-life of high-oil-containing foods.

The application of dietary fibre as microcapsule wall material in food processing

In the food industry, functional ingredients derived from active substances of natural sources and microbiological resources are gaining acceptance and demand due to their beneficial health properties. However, the inherent instability of these constituents poses a challenge in utilizing their functional properties. Microencapsulation with dietary fibre as wall material technology offers a promising solution, providing convenient manipulability and effective safeguarding of encapsulated substances. This paper presents a comprehensive overview of the current state of research on dietary fibre-based microcapsules in food processing. It examines their functional attributes, the preparation technology, and their applications within the food industry. Furthermore, the constraints associated with industrial production are discussed, as well as potential future developments. This article offers researchers a reference point and a theoretical basis for the selection of innovative food ingredients, the high-value utilisation of dietary fibre, and the design of conservation strategies for functional substances in food production.

Fabrication and optimization of ultra-long stable microencapsulated chlorophyll using combinations of wall material via response surface methodology

Nowadays, the need to use natural pigments instead of artificial colorants in food has increased due to health risks. Chlorophyll is a natural colorant with antioxidant properties. Chlorophyll is a natural pigment with superior antioxidant properties. However, this pigment is unstable in the different conditions of food processing. To increase the stability of chlorophyll extracted from Ulva intestinalis algae, encapsulation of chlorophyll with maltodextrin (MD) and whey protein isolate (WPI) carriers by two drying methods including spray drying and freeze drying was achieved. The optimum combination of wall and core materials to achieve the highest response including encapsulation efficiency (EE) and chlorophyll content (CC) was obtained by response surface methodology and central composite design. The optimal chlorophyll microcapsule (Chl-M) obtained was chosen for subsequent tests containing solubility, moisture content, and antioxidant properties. The results showed that the highest EE and CC were 90.27 ± 0.21 %, 55.36 ± 0.36 μg/mL, and 90.46 ± 0.62 %, 85.85 ± 0.43 μg/mL, respectively in SD and FD. The microcapsules produced by the freeze dryer (FD) had higher antioxidant activity (79.1 ± 0.24) than the microcapsules produced by the spray dryer (SD) (67.5 ± 0.16). The highest solubility (95.32 %) and the lowest moisture content (3.7 ± 0.05) were related to the SD. Freeze drying method (FDM) had the highest EE (91.2 %), CC (89.67 μg/mL), and antioxidant properties (79.1 %). It is hoped that the encapsulated chlorophyll can be used as a health-promoting food color additive in the food industry.

Microencapsulation of Essential Oils and Oleoresins: Applications in Food Products

Essential oils (EOs) and oleoresins (ORs) are plant-derived extracts that contain both volatile and non-volatile compounds used for flavoring, coloring, and preservation. In the food industry, they are increasingly used to replace synthetic additives, aligning with consumer demand for natural ingredients, by substituting artificial flavors, colorants, and preservatives. Microcapsules can be added to a vast range of foods and beverages, including bakery products, candies, meat products, and sauces, as well as active food packages. However, incorporating EOs and ORs into foods and beverages can be difficult due to their hydrophobic nature and poor stability when exposed to light, oxygen, moisture, and temperature. Microencapsulation techniques address these challenges by enhancing their stability during storage, protecting sensitive molecules from reacting in the food matrix, providing controlled release of the core ingredient, and improving dispersion in the medium. There is a lack of articles that research, develop, and optimize formulations of microencapsulated EOs and ORs to be incorporated into food products. Microencapsulated ORs are overlooked by the food industry, whilst presenting great potential as natural and more stable alternatives to synthetic flavors, colorants, and preservatives than the pure extract. This review explores the more common microencapsulation methods of EOs and ORs employed in the food industry, with spray drying being the most widely used at an industrial scale. New emerging techniques are explored, with a special focus on spray drying-based technologies. Categories of wall materials and encapsulated ingredients are presented, and their applications in the food and beverage industry are listed.

Regulation of mechanical properties of microcapsules and their applications

Microcapsules encapsulating payloads are one of the most promising delivery methods. The mechanical properties of microcapsules often determine their application scenarios. For example, microcapsules with low mechanical strength are more widely used in biomedical applications due to their superior biocompatibility, softness, and deformability. In contrast, microcapsules with high mechanical strength are often mixed into the matrix to enhance the material. Therefore, characterizing and regulating the mechanical properties of microcapsules is essential for their design optimization. This paper first outlines four methods for the mechanical characterization of microcapsules: nanoindentation technology, parallel plate compression technology, microcapillary technology, and deformation in flow. Subsequently, the mechanisms of regulating the mechanical properties of microcapsules and the progress of applying microcapsules with different degrees of softness and hardness in food, textile, and pharmaceutical formulations are discussed. These regulation mechanisms primarily include altering size and morphology, introducing sacrificial bonds, and construction of hybrid shells. Finally, we envision the future applications and research directions for microcapsules with tunable mechanical properties.

Microencapsulation Techniques in HIV Pediatric Formulations: Advances and Future Outlook

The treatment of human immunodeficiency virus (HIV) in children has persistently been complex and tedious on a global scale. This is because adult and pediatric HIV treatments follow a similar therapeutic approach. Due to the dearth of clinically licensed pediatric antiretroviral drug (ARVD) therapy, children with HIV worldwide are prescribed unlicensed drugs each year. This has triggered likelihood of poor drug adherence, therapeutic failure, and even adverse reactions brought on by a variety of factors, including pill size and quantity, which is the main cause of swallowing difficulties, repeated administration of these various ARVDs, many of which have poor solubility and cause severe side effects in children, and unpalatability of the drug, which is one of the criteria for pediatric formulations. Thus, there is a necessity for investigation into several advanced microencapsulation techniques that could curb these challenges. Microencapsulation techniques have explored in drug delivery for encapsulation and manufacture of different nanoparticles that have shown significant potential in mitigating and surmounting different constraints, such as taste masking, enhanced drug solubility and bioavailability, and production of micronized fine powders for treatment of varying diseases. Nevertheless, the usage of these technologies in HIV pediatric formulations has garnered relatively little attention. Thus, this review has paid a keen interest in examining several microencapsulation strategies for potential utilization in the development of HIV pediatric formulations.

Exploring the impact of encapsulation on the stability and bioactivity of peptides extracted from botanical sources: trends and opportunities

Bioactive peptides derived from plant sources have gained significant attention for their potential use in preventing and treating chronic degenerative diseases. However, the efficacy of these peptides depends on their bioaccessibility, bioavailability, and stability. Encapsulation is a promising strategy for improving the therapeutic use of these compounds. It enhances their stability, prolongs their shelf life, protects them from degradation during digestion, and enables better release control by improving their bioaccessibility and bioavailability. This review aims to analyze the impact of various factors related to peptide encapsulation on their stability and release to enhance their biological activity. To achieve this, it is necessary to determine the composition and physicochemical properties of the capsule, which are influenced by the wall materials, encapsulation technique, and operating conditions. Furthermore, for peptide encapsulation, their charge, size, and hydrophobicity must be considered. Recent research has focused on the advancement of novel encapsulation methodologies that permit the formation of uniform capsules in terms of size and shape. In addition, it explores novel wall materials, including polysaccharides derived from unconventional sources, that allow the precise regulation of the rate at which peptides are released into the intestine.

Application of encapsulated flavors in food products; opportunities and challenges

Flavors are considered among the most important components of food formulations since they can predominantly affect the consumer acceptance and satisfaction. However, most flavors are highly volatile and inherently sensitive to pH, light, thermal processes, and chemical reactions such as oxidation and hydrolysis. Encapsulation is used as an effective strategy for protecting flavors from environmental conditions and extending their shelf life. Moreover, release characteristics of flavors can be modified via application of appropriate carriers and wall materials. This review focuses on the use of encapsulated flavors in various food products. Various factors affecting flavor retention during encapsulation, flavor release mechanisms, profiles and kinetics are discussed. Finally, the challenges associated with the use of encapsulated flavors in food products (in situ) and to model systems (in vitro), their storage stability, product requirements and problems related to the market are presented.

Encapsulation of conjugated linoleic acid and ruminant trans fatty acids to study the prevention of metabolic syndrome-a review

Studies have reported the potential benefits of consuming conjugated linoleic acid (CLA) and ruminant trans fatty acids (R-TFAs) in reducing the risk factors of metabolic syndrome (MetS). In addition, encapsulation of CLA and R-TFAs may improve their oral delivery and further decrease the risk factors of MetS. The objectives of this review were (1) to discuss the advantages of encapsulation; (2) to compare the materials and techniques used for encapsulating CLA and R-TFAs; and (3) to review the effects of encapsulated vs non-encapsulated CLA and R-TFAs on MetS risk factors. Examination of papers citing micro- and nano-encapsulation methods used in food sciences, as well as the effects of encapsulated vs non-encapsulated CLA and R-TFAs, was conducted using the PubMed database. A total of 84 papers were examined; of these, 18 studies were selected that contained information on the effects of encapsulated CLA and R-TFAs. The 18 studies that described encapsulation of CLA or R-TFAs indicated that micro- or nano-encapsulation processes stabilized CLA and prevented oxidation. CLA was mainly encapsulated using carbohydrates or proteins. So far, oil-in-water emulsification followed by spray-drying were the frequently used techniques for encapsulation of CLA. Further, 4 studies investigated the effects of encapsulated CLA on MetS risk factors compared with non-encapsulated CLA. A limited number of studies investigated the encapsulation of R-TFAs. The effects of encapsulated CLA or R-TFAs on the risk factors for MetS remain understudied; thus, additional studies comparing the effects of encapsulated and non-encapsulated CLA or R-TFAs are needed.

Production of bioactive and functional frozen yogurt through easy-to-make microspheres incorporation

In the food industry, the microencapsulation process is important to control the release of active encapsulated ingredients, mask unwanted flavors, colors, and unpleasant smells, increase shelf life, and protect encapsulated components from light, moisture, and nutritional loss. In this process, microspheres are formed using cross-linked polymer, which can incorporate aqueous or oily ingredients, using simple physicochemical methods of phase separation by coacervation, without the need for organic solvents. In this context, this study aimed to develop bioactive, functional frozen yogurt through the incorporation of microspheres loaded with ascorbic acid or omega 3. The process used resulted in small microspheres (15-80 μm), imperceptible to the palate, and capable of swelling about 14 times, being suitable for incorporating omega 3, without altering the swelling, and extending the shelf life of the ascorbic acid for 6 weeks, even in an acid medium. Also, the matrix does not affect the properties of frozen yogurt and acts as a stabilizer, contributing to reduce the melting rate. The sensory analysis proved that encapsulation was promising to mask the taste and odor of omega 3 and to protect the ascorbic acid, without altering the properties and quality of the frozen product.

Application of spray drying, spray chilling and the combination of both methods to produce tucumã oil microparticles: characterization, stability, and β-carotene bioaccessibility

The aim of this work was to produce tucumã oil (PO) microparticles using different encapsulation methods, and to evaluate their properties, storage stability and bioaccessibility of the encapsulated β-carotene. Gum Arabic was used as carrier for spray drying (SD), while vegetable fat was the wall material for spray chilling (SC) and the combination of the methods (SDC). Powders were yellow (hue angle around 80°) and presented particles with small mean diameters (1.57-2.30 µm). PO and the microparticles possess high β-carotene contents (∼0.35-22 mg/g). However, some carotenoid loss was observed in the particles after encapsulation by SD and SDC (around 20%). After 90 days of storage, SDC particles presented the lowest degradation of total carotenoids (∼5%), while SD samples showed the highest loss (∼21%). Yet, the latter had the lowest contents of conjugated dienes (4.1-5.3 µmol/g) among treatments. At the end of simulated digestion, PO and the microparticles provided low β-carotene bioaccessibility (<10%), and only SC increased this parameter compared to the pure oil. In conclusion, carotenoid-rich microparticles with attractive color were obtained through microencapsulation of PO by SD, SC and SDC, revealing their potential as natural additives for the development of food products with improved nutritional properties. The SC method stood out for providing microparticles with high carotenoid content and retention, high oxidative stability, and improved β-carotene bioaccessibility.

Recent Advances in the Microencapsulation of Essential Oils, Lipids, and Compound Lipids through Spray Drying: A Review

In recent decades, the microcapsules of lipids, compound lipids, and essential oils, have found numerous potential practical applications in food, textiles, agricultural products, as well as pharmaceuticals. This article discusses the encapsulation of fat-soluble vitamins, essential oils, polyunsaturated fatty acids, and structured lipids. Consequently, the compiled information establishes the criteria to better select encapsulating agents as well as combinations of encapsulating agents best suited to the types of active ingredient to be encapsulated. This review shows a trend towards applications in food and pharmacology as well as the increase in research related to microencapsulation by the spray drying of vitamins A and E, as well as fish oil, thanks to its contribution of omega 3 and omega 6. There is also an increase in articles in which spray drying is combined with other encapsulation techniques, or modifications to the conventional spray drying system.

Characterization of Cassava Starch Extruded Sheets Incorporated with Tucumã Oil Microparticles

The application of biopolymers and feasible technologies to obtain sheets is crucial for the large-scale production of food packages and for reducing plastic pollution. Additionally, the inclusion of additives in sheets can affect and improve their properties. This work aimed to incorporate tucumã oil (TO) and TO microparticles produced by spray drying (SD), spray chilling (SC), and their combination (SDC) into extruded cassava starch sheets and to evaluate the effect of such addition on their physical, optical, and mechanical properties. Gum Arabic and vegetable fat were used as wall materials for SD and SC/SDC, respectively. The sheets enriched with tucumã oil (FO) and the microparticles produced by SD, SC and SDC (FSD, FSC, and FSDC, respectively) presented yellow color (hue angle around 90°) and higher opacity (11.6–25.3%) when compared to the control (6.3%). All sheets showed high thickness (1.3–1.8 mm), and the additives reduced the water solubility of the materials (from 27.11% in the control to 24.67–25.54% in enriched samples). The presence of large SDC particles, as evidenced by Scanning Electron Microscopy (SEM), caused discontinuity of the sheet structure and decreased mechanical strength of the FSDC. One may conclude that potential active packages were obtained by extrusion of cassava starch sheets added with pure and encapsulated TO.

Coacervation as a Novel Method of Microencapsulation of Essential Oils-A Review

These days, consumers are increasingly "nutritionally aware". The trend of "clean label" is gaining momentum. Synthetic additives and preservatives, as well as natural ones, bearing the E symbol are more often perceived negatively. For this reason, substances of natural origin are sought tfor replacing them. Essential oils can be such substances. However, the wider use of essential oils in the food industry is severely limited. This is because these substances are highly sensitive to light, oxygen, and temperature. This creates problems with their processing and storage. In addition, they have a strong smell and taste, which makes them unacceptable when added to the product. The solution to this situation seems to be microencapsulation through complex coacervation. To reduce the loss of essential oils and the undesirable chemical changes that may occur during their spray drying-the most commonly used method-complex coacervation seems to be an interesting alternative. This article collects information on the limitations of the use of essential oils in food and proposes a solution through complex coacervation with plant proteins and chia mucilage.

Microencapsulation of Erythrocytes Extracted from Cavia porcellus Blood in Matrices of Tara Gum and Native Potato Starch

Ferropenic anemy is the leading iron deficiency disease in the world. The aim was to encapsulate erythrocytes extracted from the blood of Cavia porcellus, in matrices of tara gum and native potato starch. For microencapsulation, solutions were prepared with 20% erythrocytes; and encapsulants at 5, 10, and 20%. The mixtures were spray-dried at 120 and 140 °C. The iron content in the erythrocytes was 3.30 mg/g and between 2.32 and 2.05 mg/g for the encapsulates (p < 0.05). The yield of the treatments varied between 47.84 and 58.73%. The moisture, water activity, and bulk density were influenced by the temperature and proportion of encapsulants. The total organic carbon in the atomized samples was around 14%. The particles had diverse reddish tonalities, which were heterogeneous in their form and size; openings on their surface were also observed by SEM. The particle size was at the nanometer level, and the zeta potential (ζ) indicated a tendency to agglomerate and precipitation the solutions. The presence of iron was observed on the surface of the atomized by SEM-EDX, and FTIR confirmed the encapsulation due to the presence of the chemical groups OH, C-O, C-H, and N-H in the atomized. On the other hand, high percentages of iron release in vitro were obtained between 88.45 and 94.71%. The treatment with the lowest proportion of encapsulants performed at 140 °C obtained the best results and could potentially be used to fortify different functional foods.

Microencapsulation by spray chilling in the food industry: Opportunities, challenges, and innovations

Background

The increasing demand for healthy eating habits and the emergence of the COVID-19 pandemic, which resulted in a health crisis and global economic slowdown, has led to the consumption of functional and practical foods. Bioactive ingredients can be an alternative for healthy food choices; however, most functional compounds are sensitive to the adverse conditions of processing and digestive tract, impairing its use in food matrices, and industrial-scale applications. Microencapsulation by spray chilling can be a viable alternative to reduce these barriers in food processing.

Scope and approach

This review discusses the use of spray chilling technique for microencapsulation of bioactive food ingredients. Although this technology is known in the pharmaceutical industry, it has been little exploited in the food sector. General aspects of spray chilling, the process parameters, advantages, and disadvantages are addressed. The feasibility and stability of encapsulated bioactive ingredients in food matrices and the bioavailability in vitro of solid lipid microparticles produced by spray chilling are also discussed.

Main findings and conclusions

Research on the microencapsulation of bioactive ingredients by spray chilling for use in foods has shown the effectiveness of this technique to encapsulate bioactive compounds for application in food matrices. Solid microparticles produced by spray chilling can improve the stability and bioavailability of bioactive ingredients. However, further studies are required, including the use of lipid-based encapsulating agents, process parameters, and novel formulations for application in food, beverages, and packaging, as well as in vivo studies to prove the effectiveness of the formulations.

Microencapsulation as a Noble Technique for the Application of Bioactive Compounds in the Food Industry: A Comprehensive Review

The use of natural food ingredients has been increased in recent years due to the negative health implications of synthetic ingredients. Natural bioactive compounds are important for the development of health-oriented functional food products with better quality attributes. The natural bioactive compounds possess different types of bioactivities, e.g., antioxidative, antimicrobial, antihypertensive, and antiobesity activities. The most common method for the development of functional food is the fortification of these bioactive compounds during food product manufacturing. However, many of these natural bioactive compounds are heat-labile and less stable. Therefore, the industry and researchers proposed the microencapsulation of natural bioactive compounds, which may improve the stability of these compounds during processing and storage conditions. It may also help in controlling and sustaining the release of natural compounds in the food product matrices, thus, providing bioactivity for a longer duration. In this regard, several advanced techniques have been explored in recent years for microencapsulation of bioactive compounds, e.g., essential oils, healthy oils, phenolic compounds, flavonoids, flavoring compounds, enzymes, and vitamins. The efficiency of microencapsulation depends on various factors which are related to natural compounds, encapsulating materials, and encapsulation process. This review provides an in-depth discussion on recent advances in microencapsulation processes as well as their application in food systems.

Probiotics in Functional Foods: Survival Assessment and Approaches for Improved Viability

Nowadays, food is no longer just for nutrition. Consumers are more demanding and expect to get health benefits from their daily meals. Various areas of the food industry are in great demand of functional chemicals to enhance the taste and nutritional value of their products. Probiotic bacteria have already been part of the human’s routine for good gut microbiota maintenance in terms of pharmaceutical products. Their incorporation in food however is a challenging task that offers great opportunities but has limitations as well. Specifically, the purpose of this review is to emphasize the importance of probiotics in food, to assess their survival through gastrointestinal tract, and to highlight the recent advances in approaches for their improved viability.

Encapsulation of volatile compounds in liquid media: Fragrances, flavors, and essential oils in commercial formulations

The first marketed example of the application of microcapsules dates back to 1957. Since then, microencapsulation techniques and knowledge have progressed in a plethora of technological fields, and efforts have been directed toward the design of progressively more efficient carriers. The protection of payloads from the exposure to unfavorable environments indeed grants enhanced efficacy, safety, and stability of encapsulated species while allowing for a fine tuning of their release profile and longer lasting beneficial effects. Perfumes or, more generally, active-loaded microcapsules are nowadays present in a very large number of consumer products. Commercial products currently make use of rigid, stable polymer-based microcapsules with excellent release properties. However, this type of microcapsules does not meet certain sustainability requirements such as biocompatibility and biodegradability: the leaking via wastewater contributes to the alarming phenomenon of microplastic pollution with about 4% of total microplastic in the environment. Therefore, there is a need to address new issues which have been emerging in relation to the poor environmental profile of such materials. The progresses in some of the main application fields of microencapsulation, such as household care, toiletries, cosmetics, food, and pesticides are reviewed herein. The main technologies employed in microcapsules production and the mechanisms underlying the release of actives are also discussed. Both the advantages and disadvantages of every technique have been considered to allow a careful choice of the most suitable technique for a specific target application and prepare the ground for novel ideas and approaches for encapsulation strategies that we expect to be proposed within the next years.

Rational Design of Sustainable Liquid Microcapsules for Spontaneous Fragrance Encapsulation

The high volatility, water-immiscibility, and light/oxygen-sensitivity of most aroma compounds represent a challenge to their incorporation in liquid consumer products. Current encapsulation methods entail the use of petroleum-based materials, initiators, and crosslinkers as well as mixing, heating, and purification steps. Hence, more efficient and eco-friendly approaches to encapsulation must be sought. Herein, we propose a simple method by making use of a pre-formed amphiphilic polymer and employing the Hansen Solubility Parameters approach to determine which fragrances could be encapsulated by spontaneous coacervation in water. The coacervates do not precipitate as solids but they remain suspended as colloidally stable liquid microcapsules, as demonstrated by fluorescence correlation spectroscopy. The effective encapsulation of fragrance is proven through confocal Raman spectroscopy, while the structure of the capsules is investigated by means of cryo FIB/SEM, confocal laser scanning microscopy, and small-angle X-ray scattering.

Recent Advances on Nanoparticle Based Strategies for Improving Carotenoid Stability and Biological Activity

Carotenoids are natural pigments widely used in food industries due to their health-promoting properties. However, the presence of long-chain conjugated double bonds are responsible for chemical instability, poor water solubility, low bioavailability and high susceptibility to oxidation. The application of a nanoencapsulation technique has thus become a vital means to enhance stability of carotenoids under physiological conditions due to their small particle size, high aqueous solubility and improved bioavailability. This review intends to overview the advances in preparation, characterization, biocompatibility and application of nanocarotenoids reported in research/review papers published in peer-reviewed journals over the last five years. More specifically, nanocarotenoids were prepared from both carotenoid extracts and standards by employing various preparation techniques to yield different nanostructures including nanoemulsions, nanoliposomes, polymeric/biopolymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid nanoparticles, supercritical fluid-based nanoparticles and metal/metal oxide nanoparticles. Stability studies involved evaluation of physical stability and/or chemical stability under different storage conditions and heating temperatures for varied lengths of time, while the release behavior and bioaccessibility were determined by various in vitro digestion and absorption models as well as bioavailability through elucidating pharmacokinetics in an animal model. Moreover, application of nanocarotenoids for various biological applications including antioxidant, anticancer, antibacterial, antiaging, cosmetics, diabetic wound healing and hepatic steatosis were summarized.

Smart-Responsive Colloidal Capsules as an Emerging Tool to Design a Multifunctional Lubricant Additive

The microencapsulation technique has been proven as a powerful and flexible tool to design and develop a multifunctional additive for various applications. The significant characteristics of this technique center around the ability to control the release of the core active ingredients by tuning the porosity and the permeability of the shell. However, this original concept has faced a major roadblock in lubricant research since it causes a major breakage of the microcapsules (∼70%) under severe stressed-shearing conditions. The shell fragments generated from such unwanted events significantly influence the friction and wear performances of the counterpart, thus limiting the ongoing research of the microencapsulation technique in tribology. To solve such technical bottlenecks, we develop a new strategy of utilizing the microencapsulation technique which focuses on the smart responsiveness of the shell with the base lubricant and the synergy between the incorporated materials. In this study, the smart-responsive colloidal capsule has been developed based on our proposed concept that demonstrates outstanding performances in improving the lubricity of the conventional melt lubricant (by ∼70%) under hot metal working conditions. An unprecedented oxidation-reduction (by ∼93%) and the first instance of ultralow friction (0.07) at elevated temperatures (880 °C) have been initially achieved. This work opens a new avenue of customizing a multifunctional additive package by utilizing the smart colloidal capsules in lubrication science.

Potential of Nanonutraceuticals in Increasing Immunity

Nutraceuticals are defined as foods or their extracts that have a demonstrably positive effect on human health. According to the decision of the European Food Safety Authority, this positive effect, the so-called health claim, must be clearly demonstrated best by performed tests. Nutraceuticals include dietary supplements and functional foods. These special foods thus affect human health and can positively affect the immune system and strengthen it even in these turbulent times, when the human population is exposed to the COVID-19 pandemic. Many of these special foods are supplemented with nanoparticles of active substances or processed into nanoformulations. The benefits of nanoparticles in this case include enhanced bioavailability, controlled release, and increased stability. Lipid-based delivery systems and the encapsulation of nutraceuticals are mainly used for the enrichment of food products with these health-promoting compounds. This contribution summarizes the current state of the research and development of effective nanonutraceuticals influencing the body's immune responses, such as vitamins (C, D, E, B12, folic acid), minerals (Zn, Fe, Se), antioxidants (carotenoids, coenzyme Q10, polyphenols, curcumin), omega-3 fatty acids, and probiotics.