As an excellent delivery material for bioactive compounds, zein nanoparticles are limited by colloidal instability. Recently, the development of their surface coating has greatly promoted the ...performance of the zein-based delivery system. In the future, surface-coated zein nanoparticles delivering bioactive compounds will have broader applications in the food industry.
This review focuses on introducing different methods and materials of surface-coated zein nanoparticles and their encapsulated bioactive compounds, including the assessments for the improved application of these compounds. Additionally, the application in food-related fields is summarized. Finally, some challenges regarding the surface coating of zein nanoparticles and development trends are presented.
Currently, methods for surface coating of zein nanoparticles include antisolvent precipitation, antisolvent co-precipitation, layer-by-layer, solvent evaporation, and pH-driven. The materials are mainly proteins, polysaccharides, surfactants, and their composites. It can not only deliver a single bioactive compound but also achieve co-delivery. The evaluation of the improved compound application includes physical and chemical stability, controlled release/bioaccessibility, and biological activity. Moreover, surface-coated zein nanoparticles can be applied to Pickering emulsions and edible films. There are also some challenges in surface coating development. The future will be to improve the application of zein carriers in commercial products, and laboratory-level researches including new system development, smart co-delivery design, and bioavailability mechanism. In conclusion, surface coating of zein nanoparticles have a bright prospect to improve the application of bioactive compounds in the food industry.
•Methods of surface-coating are introduced like antisolvent precipitation.•Material of surface-coating are mainly proteins, polysaccharides, and surfactants.•Single and co-delivery of bioactive compounds were discussed.•The application of surface-coated zein nanoparticles in food field was reviewed.
In this work, zein/soluble soybean polysaccharide (SSPS) composite nanoparticles were fabricated using a facile antisolvent precipitation method to encapsulate lutein. The ternary system can ...self-assemble to spherical nanoparticles (about 200 nm) with relatively uniform size (PDI around 0.15) and negative charge (about −33.56 mV). For the 25:1 mass ratio of zein to lutein, the encapsulation efficiency was higher than 80%. Notably, the encapsulation was dominated by zein which could bind lutein and form zein-lutein complexes spontaneously in aqueous ethanol. The aqueous solubility and chemical stability of lutein were both enhanced greatly upon encapsulation. The composite nanoparticles also showed exceptional pH stability and elevated salt stability. Cytotoxicity assay indicated thee nanocarriers are non-toxic and biocompatible. The bioaccessibility of encapsulated lutein (32.11%) was greatly higher than that of non-encapsulated lutein (16.21%). These results suggested that zein/SSPS composite nanoparticles may be a promising delivery system for lutein, which could be used as an ingredient for the formulation of beverages or functional foods.
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•Zein-based nanoparticles can effectively encapsulate and protect lutein.•Colloidal stability was improved by soluble soybean polysaccharide coating.•Lutein-loaded composite nanoparticles are nontoxic and biocompatible.•In vitro bioaccessibility of lutein was enhanced significantly with encapsulation.
Lutein is a hydrophobic carotenoid with various beneficial biological activities. Its use as a functional food, however, is currently limited by its low-water solubility, chemical instability, and ...poor bioavailability. The purpose of this work is to fabricate lutein-loaded nanoparticles to overcome these challenges. Lutein was encapsulated in zein nanoparticles coated with sophorolipid (ZSLNPs). The properties of ZSLNPs were characterized by transmission electron microscopy and dynamic light scattering. The results showed that the ZSLNPs were spheres with particle size around 200 nm and negative surface potentials (ζ = −54 mV). The encapsulation efficiency and loading capacity of the lutein in the ZSLNPs was 90.04% and 0.82%, respectively. Infrared spectroscopy analysis indicated that the dominant driving forces of the ZSLNPs formation mainly included electrostatic, hydrophobic interactions and hydrogen bonding. X-ray analysis showed that the encapsulated lutein was in an amorphous form. Circular dichroism analysis suggested that the incorporation of lutein or sophorolipid led to the change in secondary structure of zein. In addition, the ZSLNPs had good stability, redispersibility, and increased the water solubility of lutein. Furthermore, in vitro studies showed that the ZSLNPs had great biocompatibility and bioaccessibility of lutein. Overall, these findings indicated that the core/shell nanoparticles developed in the work may be suitable for encapsulating this important nutrient in functional foods.
•Shellac can nano-encapsulate curcumin by pH cycle.•The starting point of the design is economy, simplicity, energy saving and safety.•High loading capacity of curcumin is the unique advantage of ...shellac nanoparticles.•The nanoparticles had good physicochemical stability and bioaccessibility.•The redispersibility is proportional to the mass ratio of shellac-to-curcumin.
Curcumin is an active ingredient with multiple functions, however, its application is limited by its low stability, bioaccessibility, freeze-dried redispersibility, and solubilization. The work aims to improve the application of curcumin (Cur) by encapsulation. Shellac was the wall material inspired by its pH-dependent deprotonation and amphiphilic nature to form nanoparticles. The curcumin/shellac nanoparticles (S/Cur) exhibited a bright spot of high loading capacity (the maximum of higher than 70 %), while still having high encapsulation efficiency (the minimum of higher than 85 %). Transmission electron microscopy showed that S/Cur was a spherical structure. It exhibited good physical stability, including pH (4.0–8.0), ionic strength (NaCl, < 900 mM), thermo stability (80 ℃, 180 min), and storage stability (light and dark, 4 and 25 ℃, 20 days). Meanwhile, the chemical stability was increased by encapsulation. Furthermore, the bioaccessibility of Cur was improved to 75.95 %, which is attributed to the pH response of shellac. Additionally, S/Cur had freeze-dried redispersibility and solubilization, which is proportional to the mass ratio of shellac-to-Cur. The mechanism of S/Cur formation involved hydrophobic interaction and hydrogen bonds, and the nanoconfined Cur was amorphous.
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•Multiple forms of curcumin-based co-delivery systems are detailed.•The functional properties of curcumin-based co-delivery systems are discussed.•Practical food application of ...curcumin-based co-delivery systems is introduced.•Future trends of curcumin-based co-delivery systems are given.
Currently, curcumin-based co-delivery systems are receiving widespread attention. However, a systematic summary of the possibility of curcumin-based co-delivery systems used for the food industry from multiple directions based on the functional characteristics of curcumin is lacking. This review details the different forms of curcumin-based co-delivery systems including the single system of nanoparticle, liposome, double emulsion, and multiple systems composed of different hydrocolloids. The structural composition, stability, encapsulation efficiency, and protective effects of these forms are discussed comprehensively. The functional characteristics of curcumin-based co-delivery systems are summarized, involving biological activity (antimicrobial and antioxidant), pH-responsive discoloration, and bioaccessibility/bioavailability. Correspondingly, potential applications for food preservation, freshness detection, and functional foods are introduced. In the future, more novel co-delivery systems for active ingredients and food matrices should be developed. Besides, the synergistic mechanisms between active ingredients, delivery carrier/active ingredient, and external physical condition/active ingredient should be explored. In conclusion, curcumin-based co-delivery systems have the potential to be widely used in the food industry.
•The promotion development of fucoxanthin delivery systems was proposed in 3 ways.•The encapsulated materials mainly included protein, polysaccharide, and lipid.•The stability and bioactivity of ...fucoxanthin were improved by delivery systems.•The release and bioavailability of fucoxanthin were enhanced by delivery systems.•The application of fucoxanthin in food was limited.
Fucoxanthin is a carotenoid derived from marine algae/microalgae, which has wide application in the food industry. This review first proposes the promotion development of fucoxanthin delivery systems from the perspective of diverse biological activities, extraction complexity, instability, poor aqueous solubility, and low bioavailability. The materials for the delivery systems of fucoxanthin mainly include protein, polysaccharide, and lipid. Colloidal structures include nanoparticles, microcapsules, emulsions, gels, coacervates, and nanofibers. Delivery systems exhibited positive effects on the stability, release, bioavailability, and bioactivity of fucoxanthin. Currently, the reported applications of fucoxanthin in food are limited. A variety of colloidal structures should be constructed to provide options for fucoxanthin applications in different foods, and the applicability of fucoxanthin colloidal structures in commercial products should be advanced. Additionally, a set of internationally unified evaluation criteria for fucoxanthin stability and bioavailability should be established.
Biopolymer-based nanoencapsulation presents great performance in the delivery of functional food ingredients. In recent years, the pH-driven method has received considerable attention due to its ...unique characteristics of low energy and organic solvent-free during the construction of biopolymer-based nanoencapsulation. This review summarized the fundamental knowledge of pH-driven biopolymer-based nanoencapsulation. The principle of the pH-driven method is the protonation reaction of functional food ingredients that change with pH. The stability of functional food ingredients in an alkaline environment is a prerequisite for the adoption of this method. pH regulator is also an important influencing factor. Different coating materials used to the pH-driven nanoencapsulation were discussed, including single and composite materials, mainly focusing on proteins. Besides, the application evaluations of pH-driven nanoencapsulation in food were analyzed. The future development trends will be the influence of pH regulators on the carrier, the design of new non-protein-based carriers, the quantification of driving forces, the absorption mechanism of encapsulated nutrients, and the molecular interaction between the wall material and the intestinal mucosa. In conclusion, pH-driven biopolymer-based nanoencapsulation of functional food ingredients will have broad prospects for development.
The application of lutein hampers due to its environmental instability, poor water solubility and bioaccessibility. The goal of this paper was to overcome these challenges by fabricating zein/tea ...saponin nanoparticles act as the vehicles of lutein (ZTSLNPs). The optimized encapsulation efficiency of ZTSLNPs was 92.91%, while the loading capacity was 1.19%. The ZTSLNPs were smooth spherical structures with mean particle size of 213 nm and negative zeta-potential. Electrostatic interactions, hydrophobic interactions, and hydrogen bonding were the main forces to form ZTSLNPs. The encapsulated lutein in ZTSLNPs was amorphous. The secondary structure of zein was changed by incorporating lutein or tea saponin. ZTSLNPs showed great stability at pH 4.0–9.0, and exhibited excellent ionic strength stability and thermal stability. Meanwhile, the ZTSLNPs effectively reduced the decomposition of lutein during 15 days storage. Furthermore, ZTSLNPs showed excellent redispersibility. Besides, the water solubility and bioaccessibility of lutein were improved by ZTSLNPs. These findings indicated that the vehicle designed in our work would be a promising strategy to improving the application of hydrophobic functional factor.
•A novel lutein delivery vehicle was fabricated using zein and tea saponin.•The addition of lutein or tea saponin led to the conformational change in zein.•Lutein-loaded zein/tea saponin nanoparticles showed good environmental stability.•Zein/tea saponin nanoparticles improved the solubility of lutein about 60 times.•The lutein in zein/tea saponin nanoparticles exhibited good bioaccessibility.
Zein-based nanoparticles loaded with bioactive compounds have positive prospects in the food industry, but an important limiting factor for development is colloidal instability. Currently, extensive ...researches are focused on solving the instability of zein nanoparticles, but since the beginning of the studies, there has not been a summary of the factors affecting the stability of zein-based nanoparticles. In the present work, the factors were reviewed comprehensively from the perspective of carrier construction and application evaluation. The former mainly includes type, quantity, and characteristics of biopolymer, the mass ratio of biopolymer/bioactive compound to zein, blending sequence of biopolymer, and location of encapsulated bioactive compounds. The latter mainly includes pH, heating, ionic strength, storage, freeze-drying, and gastrointestinal digestion. The former is the prerequisite for the success of the latter. The challenge is that stability research is limited to the laboratory level, and it is difficult to ensure that the stability results are suitable for commercial food matrices due to their complexity. At the laboratory level, the future trends are the influence of external energy and the cross-complexity and uniformity of stability research. The review is expected to provide systematic understanding and guidance for the development of zein-based nanoparticles stability.
•pH-driven zein/tea saponin composite nanoparticles were first prepared.•The system had properties of alcohol-free, low-energy and high loading capacity.•The fabricated nanoparticles had good ...physicochemical stability and redispersibility.•The solubility of curcumin increased by about 290 times for powder nanoparticles.•The designed nanoparticles increased bioaccessibility of curcumin by about 5 times.
The purpose of this paper was to overcome the challenges of curcumin by zein/tea saponin composite nanoparticles (Z/TSNPs) without any organic reagents and high-energy equipment. The spherical Z/TSNPs exhibited good physical stability, the conditions of which included pH at 5.0–8.0, heating at 80 ℃, ionic strength within 100 mM, and storage at 25 ℃ for 30 days. Meanwhile, Z/TSNPs showed excellent redispersibility. Z/TSNPs were used to encapsulate and deliver curcumin (Cur-Z/TSNPs), showing encapsulation efficiency and loading capacity of 83.73% and 22.33%, respectively. Cur-Z/TSNPs exhibited good chemical stability during storage, and the effect of light on Cur-Z/TSNPs was smaller than that of free curcumin. Furthermore, Cur-Z/TSNPs improved the solubilization and bioaccessibility of curcumin about 290 and 5 times, respectively. Besides, the encapsulation changed the crystalline state of curcumin to amorphous, and the pH-driven mechanism was probably related to hydrogen bonding, hydrophobic and electrostatic interactions.
