Thermal protection of β-carotene in re-assembled casein micelles during different processing technologies applied in food industry

Casein Functionalization Using High-Pressure Homogenization and Emulsifying Salts

In milk, casein proteins orientate themselves into spherical micellar structures with hydrophobic casein subtypes concentrated in the core, while hydrophilic casein subtypes populate the exterior. Previous research demonstrated that milk with the addition of emulsifying salts coupled with high-pressure homogenization induced an unprecedented amount of casein micelle dissociation. This research aims to quantify the extent of casein micelle dissociation in diluted skim milk and evaluate the functionality of these proteins following emulsifying salt treatment coupled with high-pressure homogenization. To evaluate the extent of micellar dissociation, dilute skim milk solutions (20% v/v) were prepared with a varying amount of treatment: no processing (control), just emulsifying salts (Treatment E, 100 mM sodium hexametaphosphate), just high-pressure homogenization (Treatment H, at 300 MPa), and EH (a combination of E and H treatments). Samples were then put through varying filter sizes (0.22 µm, 0.05 µm), and the permeates were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the control group (20% skim milk), 9.35% ± 2.53% casein protein permeated through a 0.05 µm filter. Alternatively, 93.2% ± 7.71% casein protein was present in EH samples post-filtration through a 0.05 µm filter, demonstrating a significant processing-induced dissociation of casein micelles. A potential benefit to this casein micelle size reduction is the exposure of highly functional hydrophobic subunits from the core of the micelle. In agreement, compared to the control samples, the EH samples had higher foam expansion index values (138.3% ± 12.58% vs. 33.33% ± 14.43% at 0 h), foam stability (113.3% ± 5.774% vs. 21.67% ± 2.887% after 8 h), emulsifying activity (ca. two-fold higher), and interaction with caffeine. These data demonstrate that E, coupled with H, enhances skim milk system functionality, and these changes are likely due to micellar dissociation and protein conformational changes. This work has direct applications in dairy systems (e.g., dairy foams, dairy ingredients) as well as implications for potential processing strategies for other protein-rich systems.

Advancing protein hydrolysis and phytosterol encapsulation: Emerging trends and innovations in protein-based microencapsulation techniques - A comprehensive review

Phytosterols represent a diverse and complex category of lipophilic bioactive compounds, exhibiting excellent pro-healthy properties. However, their consumption in daily diets is insufficient, and their application in food production is hindered by challenges such as low water solubility, high reactivity, and rapid degradation. The adoption of different protein or their structural modification as hydrolysates as wall material into microencapsulation techniques can be associated with improved solubility, enhanced bioaccessibility, increased bioavailability, and an extension of shelf life. This contribution provides an overview of advancements in modifying functional properties through various protein isolation methods and structural changes resulting from enzymatic hydrolysis. Additionally, the paper considers the state of the art in the utilization of various techniques and the composition of wall material in the encapsulation of phytosterols and other common lipophilic phytochemicals incorporated into delivery systems. Protein isolates obtained through novel methods of extraction may be characterized by an enhancement of their functional properties, which is crucial for the microencapsulation process. It entails not only recognizing their role as protective barriers for core materials against environmental conditions but also acknowledging their potential health-promoting attributes. These attributes encompass antioxidant properties and enhanced functional characteristics compared to native proteins. Moreover, the exploration of protein hydrolysates as versatile wall materials holds significant promise. These hydrolysates offer exceptional protective features for core materials, extending beyond mere environmental shielding. The envisioned impact extends beyond conventional delivery systems, offering transformative potential for the future of drug delivery and nutraceutical formulations.

Impact of water and oleic acid on glycerol monooleate phase transition and bi-continuous structure formation in white oil

Production of biofuels from biological feedstocks, such as soybean oil, is an important piece of the transition to renewable energy sources. Processes have been developed to co-refine these feedstocks with traditional feedstocks, however, the high concentration of polar functional groups in biofeedstocks can cause a wide range of intermediate chemical reactions and interactions. An improved understanding of the interactions of biofeedstocks and their degradation products is needed to continue to expand the usage of biofeedstocks in fuel production. In this study, the equilibrium structures of glycerol monooleate (GMO), a common intermediate product of biofeedstock processing, in white mineral oil at a wide range of compositions, temperatures, and additional byproduct concentrations (water and/or oleic acid) were characterized using small angle X-ray scattering (SAXS). It was determined that GMO can exist as crystalline aggregates in white oil or as reverse micelles depending on the concentration and temperature. The critical micelle temperature increases significantly with increasing GMO concentration but remains relatively stable with increasing water or fatty acid concentration. Fitting of the SAXS data revealed that for many compositions, the GMO formed roughly spherical reverse micelles, however, at high water concentrations (∼1 wt%), the GMO formed elongated reverse micelles. Additionally, when >1 wt% oleic acid was added to the system, bi-continuous structures were stabilized rather than discreet reverse micelles. These results help increase our understanding of the structural behavior of biofeedstock intermediate products at concentrations and temperatures relevant to biofuel production and can enable processers to design systems and products that can either leverage or prevent these interactions for improved processing performance.

Chemical modification of edible sodium caseinate: A new grafting method of oleic acid. Characterization and thermal properties of the conjugate

Sodium caseinate is a well-known amphiphilic protein derived from natural products currently used for the preparation of edible films. To improve some properties, especially to decrease the hydrophilicity and water solubility of the caseinate, the covalent grafting of a hydrophobic edible fatty acid, namely oleic acid, onto caseinate, appears to be a solution. We describe a new synthesis method for the chemical modification of sodium caseinate involving the synthesis of an acid chloride derivative from oleic acid and a phase transfer catalysis reaction in a biphasic medium. Under these conditions, free amine and alcohol groups of the caseinate are likely to be grafted with a fairly high (>50 %) substitution degree. The caseinate derivative is finely characterized, in particular by DOSY NMR, to assess the formation of a casein/oleic acid grafted compound as well as the absence of residual oleic acid.

Design of Innovative Biocompatible Cellulose Nanostructures for the Delivery and Sustained Release of Curcumin

Poor aqueous solubility, stability and bioavailability of interesting bioactive compounds is a challenge in the development of bioactive formulations. Cellulose nanostructures are promising and sustainable carriers with unique features that may be used in enabling delivery strategies. In this work, cellulose nanocrystals (CNC) and cellulose nanofibers were investigated as carriers for the delivery of curcumin, a model liposoluble compound. Nanocellulose modification with the surfactant cetyltrimethylammonium bromide (CTAB), tannic acid and decylamine (TADA), and by TEMPO-mediated oxidation were also tested and compared. The carrier materials were characterized in terms of structural properties and surface charge, while the delivery systems were evaluated for their encapsulation and release properties. The release profile was assessed in conditions that mimic the gastric and intestinal fluids, and cytotoxicity studies were performed in intestinal cells to confirm safe application. Modification with CTAB and TADA resulted in high curcumin encapsulation efficiencies of 90 and 99%, respectively. While no curcumin was released from TADA-modified nanocellulose in simulated gastrointestinal conditions, CNC-CTAB allowed for a curcumin-sustained release of ca. 50% over 8 h. Furthermore, the CNC-CTAB delivery system showed no cytotoxic effects on Caco-2 intestinal cells up to 0.125 g/L, meaning that up to this concentration the system is safe to use. Overall, the use of the delivery systems allowed for the reduction in the cytotoxicity associated with higher curcumin concentrations, highlighting the potential of nanocellulose encapsulation systems.

Structural, Binding and Functional Properties of Milk Protein-Polyphenol Systems: A Review

Polyphenols (PP) are linked to health benefits (e.g., prevention of cancer, cardiovascular disease and obesity), which are mainly attributed to their antioxidant activity. During digestion, PP are oxidised to a significant degree reducing their bio-functionality. In recent years, the potential of various milk protein systems, including β-casein micelles, β-lactoglobulin aggregates, blood serum albumin aggregates, native casein micelles and re-assembled casein micelles, to bind and protect PP have been investigated. These studies have yet to be systematically reviewed. The functional properties of the milk protein-PP systems depend on the type and concentration of both PP and protein, as well as the structure of the resultant complexes, with environmental and processing factors also having an influence. Milk protein systems protect PP from degradation during digestion, resulting in a higher bioaccessibility and bioavailability, which improve the functional properties of PP upon consumption. This review compares different milk protein systems in terms of physicochemical properties, PP binding performance and ability to enhance the bio-functional properties of PP. The goal is to provide a comprehensive overview on the structural, binding, and functional properties of milk protein-polyphenol systems. It is concluded that milk protein complexes function effectively as delivery systems for PP, protecting PP from oxidation during digestion.

Zein-Alginate-Phosphatidylcholine Nanocomplex Efficiently Delivers Lycopene and Lutein over Dietary-Derived Carotenoid Mixed Micelles in Caco-2 Cells

This study evaluated the potency of zein-alginate-phosphatidylcholine nanoparticles (NPs) on bioaccessibility/intestinal uptake of encapsulated lycopene (LY) and lutein (LT) versus dietary absorption using simulated digestion and human intestinal Caco-2 cells. LY-zein-alginate-PC (LYZAP) and LT-zein-alginate-PC (LTZAP) NPs yield desired properties, which exhibit sustained release and are suitable for oral administration. Interestingly, co-treatment of LYZAP + LTZAP showed better release of carotenoids instead of individual treatment at intestinal pH. Bioaccessibility, cellular uptake, and basolateral secretion of LY and LT from NPs were significantly enhanced than micellar carotenoids (dietary mode of absorption). The increased absorption of carotenoids from NPs correlated with triglyceride levels. The intestinal cell uptake of carotenoids by nanoencapsulation may be due to endocytosis, paracellular, and SRB-1 protein-mediated transport. Overall, LYZAP and LTZAP NPs possess superior properties to control the release and cellular uptake of unique or distinct carotenoids. The inclusion of alginate and phosphatidylcholine in zein-based nanoencapsulation could be a promising strategy to improve carotenoid bioavailability.

Improving the Bioaccessibility and Bioavailability of Carotenoids by Means of Nanostructured Delivery Systems: A Comprehensive Review

Carotenoids are bioactive compounds provided by the diet playing a key role in maintaining human health. Therefore, they should be ingested daily in an adequate amount. However, even a varied and well-balanced diet does not guarantee an adequate intake, as both the bioaccessibility and bioavailability of the compounds significantly affect their absorption. This review summarizes the main results achieved in improving the bioaccessibility and bioavailability of carotenoids by means of nanostructured delivery systems, discussing in detail the available lipid-based and biopolymeric nanocarriers at present, with a focus on their formulation and functional efficiency. Although the toxicity profile of these innovative delivery systems is not fully understood, especially for long-term intake, these systems are an effective and valuable approach to increase the availability of compounds of nutritional interest.

Recent progresses in the delivery of β-carotene: From nano/microencapsulation to bioaccessibility

Beta-carotene (BC) as an efficient pro-vitamin is effective in improving vision, immune system and cognitive function as well as preventing coronary diseases and cancer. However, besides its poor chemical stability, the high lipophilic nature of BC reduces its dispersibility and consequently bioavailability which limits its application into food, pharmaceutical and nutraceuticals. Different carriers with vesicular or particulate structures have been studied and utilized for promoting BC solubility, dispersibility, and protection against diverse operational or environmental stresses and also controlling BC release and subsequent bioaccessibility. The current study, therefore reviews different micro/nanocarriers reported on BC encapsulation with special focusing on its bioavailability. Liposomal structures have been successfully used for enhancing BC stability and bioavailability. Besides, emulsion-based carriers including Pickering emulsions, nanoemulsions and microemulsions have been widely evaluated for BC encapsulation and protection. In addition, lipid-based nanoparticles and nanostructural carriers have also been applied successfully for this context. Moreover, gel structures including emulgels, hydrogels and oleogels are studied in some researches. Most of these delivery systems led to higher hydro-solubility and dispersibility of BC which consequently increased its bioavailability; thereupon could promote its application into food, cosmetic and nutraceutical products. However, for remarkable incorporation of BC and other bioactive compounds into edible products, the safety and toxicological aspects of these delivery system especially those designed in nano scale should be addressed in the further researches.

Potential uses of milk proteins as encapsulation walls for bioactive compounds: A review

Milk proteins have received much awareness due to their bioactivity. However, their encapsulation functions have not attracted enough attention. Milk proteins as encapsulation walls can increase the bioavailability of bioactive compounds. As the benefits of bioactive compounds are critically determined by bioavailability, the effect of interactions between milk proteins and active substances is a critical topic. In the present review, we summarize the effects of milk proteins as encapsulation walls on the bioavailability of active substances with a special focus. The methods and mechanisms of interactions between milk proteins and active substances are also discussed. The evidence collected in the present review suggests that when active substances are encapsulated by milk proteins, the bioavailability of active substances can be significantly affected. This review also provides valuable guidelines for the use of milk protein-based microcarriers.

Recent Developments and Applications of Nanosystems in the Preservation of Meat and Meat Products

Due to their high water, lipid, and protein content, meat and meat products are highly perishable. The principal spoilage mechanisms involved are protein and lipid oxidation and deterioration caused by microbial growth. Therefore, efforts are ongoing to ensure food safety and increase shelf life. The development of low-cost, innovative, eco-friendly approaches, such as nanotechnology, using non-toxic, inexpensive, FDA-approved ingredients is reducing the incorporation of chemical additives while enhancing effectiveness and functionality. This review focuses on advances in the incorporation of natural additives that increase the shelf life of meat and meat products through the application of nanosystems. The main solvent-free preparation methods are reviewed, including those that involve mixing organic–inorganic or organic–organic compounds with such natural substances as essential oils and plant extracts. The performance of these additives is analyzed in terms of their antioxidant effect when applied directly to meat as edible coatings or marinades, and during manufacturing processes. The review concludes that nanotechnology represents an excellent option for the efficient design of new meat products with enhanced characteristics.

Practical application of nanoencapsulated nutraceuticals in real food products; a systematic review

In recent decades, due to the increase in awareness, most consumers prefer foods that not only satisfy their primal urge of hunger but also include health-promoting effects on the body. Therefore, the food industry has an increasing tendency to apply the nutrients (like vitamins, essential fatty acids and minerals) and replace synthetic additives with natural bioactives (like phenolics and essential oils) to produce functional products. However, low dispersibility and shelf-stability as well as presenting unpleasant taste and odor are the most critical barriers for direct incorporation of these useful compounds into foods. In this context, nanoencapsulation has been proposed as a relatively new solution to overcome the mentioned limitations. However, fewer studies have focused on incorporating the bioactive-loaded nanocarriers into the food matrices. This study intends to help the development of functional food production by doing an exhaustive review on the incorporation of nanoencapsulated ingredients into the real food system and resulted interaction of nanocarriers and food products. According to the literature, incorporation of the nanoencapsulated bioactive ingredients into foods can be effectively used to enhance their stability during the processing and storage stage and their bioavailability as well as to delay lipid oxidation and microbial growth in food, without negatively affecting physicochemical, organoleptic and qualitative properties. However, some published results to date declared that food matrix might adversely affect the bioavailability and antimicrobial activity of nanoencapsulated ingredients. It seems that further studies are required to contribute to the choice of appropriate healthy ingredients and wall materials for incorporating into a given food structure.

Advances in Protein-Based Nanocarriers of Bioactive Compounds: From Microscopic Molecular Principles to Macroscopical Structural and Functional Attributes

Many proteins can be used to fabricate nanocarriers for encapsulation, protection, and controlled release of nutraceuticals. This review examined the protein-based nanocarriers from microscopic molecular characteristics to the macroscopical structural and functional attributes. Structural, physical, and chemical properties of protein-based nanocarriers were introduced in detail. The spatial size, shape, water dispersibility, colloidal stability, etc. of protein-based nanocarriers were largely determined by the molecular physicochemical principles of protein. Different preparative techniques, including antisolvent precipitation, pH-driven, electrospray, and gelation methods, among others, can be used to fabricate different protein-based nanocarriers. Various modifications based on physical, chemical, and enzymatic approaches can be used to improve the functional performance of these nanocarriers. Protein is a natural resource with a wide range of sources, including plant, animal, and microbial, which are usually used to fabricate the nanocarriers. Protein-based nanocarriers have many advantages in aid of the application of bioactive ingredients to the medical, food, and cosmetic industries.

Self-assembled nano-micelles of lactoferrin peptides: Structure, physicochemical properties, and application for encapsulating and delivering curcumin

Food-derived protein hydrolysate exhibits good bioactivity, compatibility, and low toxicity, etc. However, the information on protein hydrolysate-based micelles and their application as carriers for hydrophobic bioactive compounds is limited. In this study, an enzymatic partially hydrolyzed lactoferrin hydrolysate nano-micelle with the size within 50 nm was constructed, and its formation mechanism and delivery characteristics for curcumin (Cur) were studied. The results demonstrated that Cur was loaded into the micelles through hydrophobic interaction, and the encapsulation rate of Cur by nano-micelles was (93.44 ± 0.01)%. In addition, the nano-micelle system demonstrated excellent thermal stability, dilution stability, and storage stability. The in vitro simulated digestion proved that self-assembled nano-micelles could improve the transformation rate and bioaccessibility of Cur. This study revealed that lactoferrin hydrolysate self-assembled nano-micelle is a promising delivery system for hydrophobic bioactive compounds.

Comparative performance evaluation of chitosan based polymeric microspheres and nanoparticles as delivery system for bacterial β-carotene derived from Planococcus sp. TRC1

β-carotene is a natural compound with immense healthcare benefits. To overcome insolubility and lack of stability which restricts its application, in this study, β-carotene from Planococcus sp. TRC1 was entrapped into formulations of chitosan‑sodium alginate microspheres (MF1, MF2 and MF3) and chitosan nanoparticles (NF1, NF2 and NF3). The maximum entrapment efficiency (%) and loading capacity (%) were 80.6 ± 4.28 and 26 ± 3.05 (MF2) and 92.1 ± 3.44 and 41.86 ± 4.65 (NF2) respectively. Korsmeyer-Peppas model showed best fit with release, revealing non-Fickian diffusion. Thermal and UV treatment exhibited higher activation energy (kJ/mol), 17.76 and 15.57 (MF2) and 37.03 and 19.33 (NF2) compared to free β-carotene (3.7 and 3.9), uncovering enhanced stability. MF2 and NF2 revealed swelling index (%) 721 ± 1.7 and 18.1 ± 1.5 (pH 6.8) and particle size 69.5 ± 3.2 μm and 92 ± 2.5 nm respectively. FESEM, FT-IR, XRD and DSC depicted spherical morphology, intactness of functional groups and masking of crystallinity. The IC₅₀ (μg ml^-1) values for antioxidant and anticancer (A-549) activities were 33.1 ± 1.7, 45.1 ± 2.8, 39.3 ± 2.9 and 31.3 ± 1.7, 27.9 ± 2.4, 25.3 ± 2.2 for β-carotene, MF2 and NF2 respectively with no significant cytotoxicity on HEK-293 cells and RBCs (p > 0.05). This comparative study of microspheres and nanoparticles may allow the diverse applications of an unconventional bacterial β-carotene with promising stability and efficacies.

Interactions between puerarin/daidzein and micellar casein

Puerarin (PUE) and daidzein (DAI) are polyphenols with extensive biological activities. In the present study, the interactions between PUE/DAI and micellar casein (MC) were investigated, and the physicochemical properties of their complexes were analyzed. The results of fluorescence spectrum analysis and molecular docking revealed that the main interactions between DAI and MC were hydrophobic forces, while that between PUE and MC was hydrogen bonding. The FTIR and XRD analyses confirmed the formation of complexes between MC and PUE/DAI. After binding to PUE/DAI, the size of MC increased. The weight loss rate of MC decreased after complexing with PUE/DAI, but its morphology was not extensively modified. The DPPH radical scavenging capacities of PUE-MC and DAI-MC complexes were higher than those of free PUE/DAI in both water and ethanol. In vitro release experiments showed that the release rate of PUE/DAI was inhibited by MC under simulated intestinal conditions. PRACTICAL APPLICATIONS: The low water solubility and poor bioavailability of PUE and DAI limit their application. Micellar casein has high affinity for PUE and DAI. After encapsulated by micellar casein, the release rates of PUE and DAI were prolonged during simulated intestinal digestion. The results would provide useful information for improving the solubility and bioavailability of PUE and DAI, and broadening the use of them in the food and pharmaceutical industry.

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

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

Pintado M, Fernandes JC, Ramos ÓL. Novel Micro- and Nanocellulose-Based Delivery Systems for Liposoluble Compounds

Poor aqueous solubility of bioactive compounds is becoming a pronounced challenge in the development of bioactive formulations. Numerous liposoluble compounds have very interesting biological activities, but their low water solubility, stability, and bioavailability restrict their applications. To overcome these limitations there is a need to use enabling delivering strategies, which often demand new carrier materials. Cellulose and its micro- and nanostructures are promising carriers with unique features. In this context, this review describes the fast-growing field of micro- and nanocellulose based delivery systems with a focus on the release of liposoluble bioactive compounds. The state of research on this field is reviewed in this article, which also covers the chemistry, preparation, properties, and applications of micro- and nanocellulose based delivery systems. Although there are promising perspectives for introducing these materials into various fields, aspects of safety and toxicity must be revealed and are discussed in this review. The impact of gastrointestinal conditions on the systems and on the bioavailability of the bioactive compounds are also addressed in this review. This article helps to unveil the whole panorama of micro- and nanocellulose as delivery systems for liposoluble compounds, showing that these represent a great promise in a wide range of applications.

Utilization of diverse protein sources for the development of protein-based nanostructures as bioactive carrier systems: A review of recent research findings (2010-2021)

Consumer awareness of the relationship between health and nutrition has caused a substantial increase in the demand for nutraceuticals and functional foods containing bioactive compounds (BACs) with potential health benefits. However, the direct incorporation of many BACs into commercial food and beverage products is challenging because of their poor matrix compatibility, chemical instability, low bioavailability, or adverse impact on food quality. Advanced encapsulation technologies are therefore being employed to overcome these problems. In this article, we focus on the utilization of plant and animal derived proteins to fabricate micro and nano-particles that can be used for the oral delivery of BACs such as omega-3 oils, vitamins and nutraceuticals. This review comprehensively discusses different methods being implemented for fabrications of protein-based delivery vehicles, types of proteins used, and their compatibility for the purpose. Finally, some of the challenges and limitations of different protein matrices for encapsulation of BACs are deliberated upon. Various approaches have been developed for the fabrication of protein-based microparticles and nanoparticles, including injection-gelation, controlled denaturation, and antisolvent precipitation methods. These methods can be used to construct particle-based delivery systems with different compositions, sizes, surface hydrophobicity, and electrical characteristics, thereby enabling them to be used in a wide range of applications.

Micro and Nanoencapsulation of Natural Colors: a Holistic View

The applications of natural plant pigments are growing rapidly with the increasing awareness of the negative health impacts of synthetic colorants. Additionally, natural pigments possess various biological properties and therapeutic activities. But their functions are hindered by their poor bioavailability, bioaccessibility, low absorption rate, and susceptibility to destructive environmental changes during processing and delivery. Encapsulation is a method of entrapment of bioactive ingredients within suitable carriers to provide protection and for the appropriate delivery into the targeted site by the formation of particles or capsules in micrometer or nanometer scales. Encapsulation imparts several benefits including improved thermal and chemical stability, preserves or masks flavor, taste, or aroma, controlled and targeted release, and enhanced bioavailability of pigments. Micro and nanoencapsulation of pigments will provide extensive and intensive platforms for the development of a new stage in the production of novel and healthy foods. This review mainly focuses on the advanced developments in the fields of micro and nanoencapsulation of pigments.

Assembled milk protein nano-architectures as potential nanovehicles for nutraceuticals

Nanoencapsulation of hydrophobic nutraceuticals with food ingredients has become one of topical research subjects in food science and pharmaceutical fields. To fabricate food protein-based nano-architectures as nanovehicles is one of effective strategies or approaches to improve water solubility, stability, bioavailability and bioactivities of poorly soluble or hydrophobic nutraceuticals. Milk proteins or their components exhibit a great potential to assemble or co-assemble with other components into a variety of nano-architectures (e.g., nano-micelles, nanocomplexes, nanogels, or nanoparticles) as potential nanovehicles for encapsulation and delivery of nutraceuticals. This article provides a comprehensive review about the state-of-art knowledge in utilizing milk proteins to assemble or co-assemble into a variety of nano-architectures as promising encapsulation and delivery nano-systems for hydrophobic nutraceuticals. First, a brief summary about composition, structure and physicochemical properties of milk proteins, especially caseins (or casein micelles) and whey proteins, is presented. Then, the disassembly and reassembly behavior of caseins or whey proteins into nano-architectures is critically reviewed. For caseins, casein micelles can be dissociated and further re-associated into novel micelles, through pH- or high hydrostatic pressure-mediated disassembly and reassembly strategy, or can be directly formed from caseinates through a reassembly process. In contrast, the assembly of whey protein into nano-architectures usually needs a structural unfolding and subsequent aggregation process, which can be induced by heating, enzymatic hydrolysis, high hydrostatic pressure and ethanol treatments. Third, the co-assembly of milk proteins with other components into nano-architectures is also summarized. Last, the potential and effectiveness of assembled milk protein nano-architectures, including reassembled casein micelles, thermally induced whey protein nano-aggregates, α-lactalbumin nanotubes or nanospheres, co-assembled milk protein-polysaccharide nanocomplexes or nanoparticles, as nanovehicles for nutraceuticals (especially those hydrophobic) are comprehensively reviewed. Due to the fact that milk proteins are an important part of diets for human nutrition and health, the review is of crucial importance not only for the development of novel milk protein-based functional foods enriched with hydrophobic nutraceuticals, but also for providing the newest knowledge in the utilization of food protein assembly behavior in the nanoencapsulation of nutraceuticals.

Fate of β-Carotene within Loaded Delivery Systems in Food: State of Knowledge

Nanotechnology has opened new opportunities for delivering bioactive agents. Their physiochemical characteristics, i.e., small size, high surface area, unique composition, biocompatibility and biodegradability, make these nanomaterials an attractive tool for β-carotene delivery. Delivering β-carotene through nanoparticles does not only improve its bioavailability/bioaccumulation in target tissues, but also lessens its sensitivity against environmental factors during processing. Regardless of these benefits, nanocarriers have some limitations, such as variations in sensory quality, modification of the food matrix, increasing costs, as well as limited consumer acceptance and regulatory challenges. This research area has rapidly evolved, with a plethora of innovative nanoengineered materials now being in use, including micelles, nano/microemulsions, liposomes, niosomes, solidlipid nanoparticles, nanostructured lipids and nanostructured carriers. These nanodelivery systems make conventional delivery systems appear archaic and promise better solubilization, protection during processing, improved shelf-life, higher bioavailability as well as controlled and targeted release. This review provides information on the state of knowledge on β-carotene nanodelivery systems adopted for developing functional foods, depicting their classifications, compositions, preparation methods, challenges, release and absorption of β-carotene in the gastrointestinal tract (GIT) and possible risks and future prospects.

Construction of thermally robust and porous shrimp ferritin crystalline for molecular encapsulation through intermolecular arginine-arginine attractions

Protein colloid crystals are considered as high porous soft materials, presenting great potentials in nutrients and drug encapsulation, but protein crystal fabrication usually needs precipitant and high protein concentration. Herein, an easy implemented approach was reported for the construction of protein colloid crystals in diluted solution with shimp ferritin as building blocks by taking advantage of the strength of multiple intermolecular arginine-arginine interactions. The X-ray single-crystal structure reveals that a group of exquisite arginine-arginine interactions between two neighboring ferritin enable them self-assembly into long-range ordered protein soft materials. The arginine-arginine interactions mediate crystal generation favored at pH 9.5 with 200 mM NaCl, and the resulting colloid crystals exhibit high thermal stability (90 °C for 30 min). Importantly, the interglobular cavity in colloid crystals is three times larger in volume than that of intrinsic ferritin cavity in each unit cell, which can be used for molecular encapsulation.

The influence of nanodelivery systems on the antioxidant activity of natural bioactive compounds

Bioactive compounds may lose their antioxidant activity (e.g., phenolic compounds) at elevated temperatures, enhanced oxidative conditions and severe light exposures so they should be protected by various strategies such as nano/microencapsulation methods. Encapsulation technology has been employed as a proper method for using antioxidant ingredients and to provide easy dispersibility of antioxidants in all matrices including food and pharmaceutical products. It can improve the food fortification processes, release of antioxidant ingredients, and extending the shelf-life and bioavailability of them when ingested in the intestine. In this study, our main goal is to have an overview of the influence of nanoencapsulation on the bioactivity and bioavailability, and cellular activities of antioxidant ingredients in different delivery systems. Also, the effect of encapsulation process conditions, storage conditions, carrier wall materials, and release profile on the antioxidant activity of different natural bioactives are explained. Finally, analytical techniques for measuring antioxidant activity of nanoencapsulated ingredients will be covered.

Effect of the heating process on the physicochemical characteristics and nutritional properties of whole cotyledon soymilk and tofu

This study focused on the effect of the heating process on the whole cotyledon soymilk and tofu. Whole cotyledon soymilk was made from soybean cotyledon and processed by enzymatic hydrolysis using cellulase and high-pressure homogeneity. In this study, a one-step heating method was selected for the cooking process of whole cotyledon soybean milk, and the whole cotyledon soybean milk was heated to 90 °C and held for 4 min. Results showed that the protein, total saccharides and dietary fiber content of the whole cotyledon soymilk were higher than those of the tradition soymilk due to the existence of bean dregs (okara). Both protein aggregation and protein-polysaccharide interaction were observed during the heating process. We also found a change in soymilk physicochemical characteristics such as particle size distribution, viscosity, surface hydrophobicity and soluble protein during the heating process. The results in this study showed that compared with traditional tofu, the phytic acid and trypsin inhibitor content in whole cotyledon tofu was lower, so its protein had higher digestibility in vitro. In conclusion, whole cotyledon tofu had better health properties and application prospects.

Nature-Assembled Structures for Delivery of Bioactive Compounds and Their Potential in Functional Foods

Consumers are demanding more natural, healthy, and high-quality products. The addition of health-promoting substances, such as bioactive compounds, to foods can boost their therapeutic effect. However, the incorporation of bioactive substances into food products involves several technological challenges. They may have low solubility in water or poor stability in the food environment and/or during digestion, resulting in a loss of their therapeutic properties. Over recent years, the encapsulation of bioactive compounds into laboratory-engineered colloidal structures has been successful in overcoming some of these hurdles. However, several nature-assembled colloidal structures could be employed for this purpose and may offer many advantages over laboratory-engineered colloidal structures. For example, the casein micelles and milk fat globules from milk and the oil bodies from seeds were designed by nature to deliver biological material or for storage purposes. These biological functional properties make them good candidates for the encapsulation of bioactive compounds to aid in their addition into foods. This review discusses the structure and biological function of different nature-assembled carriers, preparation/isolation methods, some of the advantages and challenges in their use as bioactive compound delivery systems, and their behavior during digestion.

Improving the efficiency of natural antioxidant compounds via different nanocarriers

Encapsulation technology, as a promising approach, has been employed for the protection and controlled release of different bioactive compounds including natural antioxidants; there are restrictions for applying these valuable ingredients in real food products, pharmaceuticals, and cosmetics such as low solubility, low shelf life, difficultly in their packaging and handling, losses due to environmental stresses and food processes, undesirable flavors and odors, untargeted release and instability in various conditions during digestion in gastrointestinal tract. Nanocarriers can be employed to overcome these challenges. There are five groups of nanocarriers based on the principal mechanism/ingredient used to make them for the encapsulation of natural antioxidants titled biopolymeric nanoparticles, lipid-based and surfactant-based nanocarriers, nanocarriers made with specially designed equipment, nature-inspired nanocarriers, and miscellaneous ones. The main goal of this study is to have an overview of role of different nanocarriers in improving the efficiency of natural antioxidant compounds for different purposes. It has been verified that antioxidant-loaded nanocarriers can be applied in many formulations with a higher and controlled release antioxidant activity, which would meet the current needs of consumers' expectations towards clean label products.

Carotenoid-loaded nanocarriers: A comprehensive review

Carotenoids retain plenty of health benefits and attracting much attention recently, but they have less resistance to processing stresses, easily oxidized and chemically unstable. Additionally, their application in food and pharmaceuticals are restricted due to some limitations such as poor bioavailability, less solubility and quick release. Nanoencapsulation techniques can be used to protect the carotenoids and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. The importance of nanocarriers in foods and pharmaceuticals cannot be denied. This review comprehensively covers recent advances in nanoencapsulation of carotenoids with biopolymeric nanocarriers (polysaccharides and proteins), and lipid-based nanocarriers, their functionalities, aptness and innovative developments in preparation strategies. Furthermore, the present state of the art encapsulation of different carotenoids via biopolymeric and lipid-based nanocarriers have been enclosed and tabulated well. Nanoencapsulation has a vast range of applications for protection of carotenoids. Polysaccharides in combination with different proteins can offer a great avenue to achieve the desired formulation for encapsulation of carotenoids by using different nanoencapsulation strategies. In terms of lipid based nanocarriers, solid lipid nanoparticles and nanostructure lipid carriers are proving as the encouraging candidates for entrapment of carotenoids. Additionally, nanoliposomes and nanoemulsion are also promising and novel-vehicles for the protection of carotenoids against challenging aspects as well as offering an effectual controlled release on the targeted sites. In the future, further studies could be conducted for exploring the application of nanoencapsulated systems in food and gastrointestinal tract (GIT) for industrial applications.