Enhancing oxidative stability of encapsulated fish oil by incorporation of ferulic acid into electrospun zein mat

Nanoencapsulation and delivery of bioactive ingredients using zein nanocarriers: approaches, characterization, applications, and perspectives

Zein has garnered widespread attention as a versatile material for nanosized delivery systems due to its unique self-assembly properties, amphiphilicity, and biocompatibility characteristics. This review provides an overview of current approaches, characterizations, applications, and perspectives of nanoencapsulation and delivery of bioactive ingredients within zein-based nanocarriers. Various nanoencapsulation strategies for bioactive ingredients using various types of zein-based nanocarrier structures, including nanoparticles, nanofibers, nanoemulsions, and nanogels, are discussed in detail. Factors affecting the stability of zein nanocarriers and characterization methods of bioactive-loaded zein nanocarrier structures are highlighted. Additionally, current applications of zein nanocarriers loaded with bioactive ingredients are summarized. This review will serve as a guide for the selection of appropriate nanoencapsulation techniques within zein nanocarriers and a comprehensive understanding of zein-based nanocarriers for specific applications in the food, pharmaceutical, cosmetic, and agricultural industries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01489-6.

Food-grade encapsulated polyphenols: recent advances as novel additives in foodstuffs

A growing inclination among consumers toward the consumption of natural products has propelled the usage of natural compounds as novel additives. Polyphenols are among the most popular candidates of natural food additives with multiple functionalities and bioactivities but are limited by instability. In this regard, a series of food-grade encapsulated polyphenols has been tailored for incorporating into food formulations as novel additives, which could better satisfy the complicated industry processing. This review seeks to present the most recent discussions regarding their application status in diverse foodstuffs as novel additives, involving functionalities, action mechanisms, and relevant encapsulation technologies. The scientific findings confirm that such novel additives show positive effects on physicochemical, sensory, and nutritional properties as well as the shelf life of diverse food matrices. However, poor heat resistance is still the major defect that restricts their application in thermal processes. Future research should focus on the evaluation of the compatibility and applicability of encapsulated polyphenols in real food processes as well as track and deepen their molecular action mechanisms in the context of complex foodstuffs. Innovation of existing encapsulation technologies should also be concerned in the future to bridge the gap between lab and scale-up production.

Preparation and Characterization of Ferulic Acid Wheat Gluten Nanofiber Films with Excellent Antimicrobial Properties

In this study, composite nanofiber films comprising polyvinyl alcohol, wheat gluten, and glucose (PWG) were fabricated using electrospinning, followed by crosslinking via Maillard crosslinking. Various mass concentrations of ferulic acid (FA) were incorporated into PWG films. The results indicated that the average diameter of the FA-PWG films decreased from 449 nm to 331 nm as the concentration of FA increased, until reaching a concentration of 12%; after which, a significant increase in diameter was observed. The subsequent Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) results suggested that FA was distributed in the sample films in an amorphous form through hydrogen and ester bonds. Additionally, release experiments and antimicrobial tests on the FA-PWG sample films showed the good controlled release of FA and excellent anti-Escherichia coli and Staphylococcus aureus activity of this film. These findings all indicate that the FA-PWG nanofiber film is a potential candidate for active food packaging.

Electrospinning and Electrospraying: Emerging Techniques for Probiotic Stabilization and Application

Probiotics are beneficial for human health. However, they are vulnerable to adverse effects during processing, storage, and passage through the gastrointestinal tract, thus reducing their viability. The exploration of strategies for probiotic stabilization is essential for application and function. Electrospinning and electrospraying, two electrohydrodynamic techniques with simple, mild, and versatile characteristics, have recently attracted increased interest for encapsulating and immobilizing probiotics to improve their survivability under harsh conditions and promoting high-viability delivery in the gastrointestinal tract. This review begins with a more detailed classification of electrospinning and electrospraying, especially dry electrospraying and wet electrospraying. The feasibility of electrospinning and electrospraying in the construction of probiotic carriers, as well as the efficacy of various formulations on the stabilization and colonic delivery of probiotics, are then discussed. Meanwhile, the current application of electrospun and electrosprayed probiotic formulations is introduced. Finally, the existing limitations and future opportunities for electrohydrodynamic techniques in probiotic stabilization are proposed and analyzed. This work comprehensively explains how electrospinning and electrospraying are used to stabilize probiotics, which may aid in their development in probiotic therapy and nutrition.

Co-encapsulation of resveratrol in fish oil microcapsules optimally stabilized by enzyme-crosslinked whey protein with gum Arabic

O/W emulsion and its spray-dried microcapsule contain the oil phase and the protein matrix, providing the potential to co-encapsulate different antioxidants. However, antioxidants were generally encapsulated in the oil phase of microcapsule, its protein matrix is rarely used. It is first to prove the possibility to encapsulate resveratrol in the emulsified oil droplets at high wall/core ratios. The optimal microcapsule with 1.75% surface oil was fabricated with 15% transglutaminase-crosslinked WPI (TGase-WPI) and 5% gum Arabic (GA). Resveratrol mainly located in the protein matrix of initial emulsion and reconstituted microcapsule. The effects of TGase-WPI/GA microcapsule and resveratrol co-encapsulation on DHA/EPA and lipid hydroperoxides/TBARS were different. The interfacial protein, the partition of resveratrol in the emulsified oil droplets and its storage stability and inhibitory effect on size change of reconstituted microcapsules increased as the polyphenol increased. These results expand the potential use of spray-dried microcapsules as co-encapsulation carriers.

Electrospun Zein/Polyoxyethylene Core-Sheath Ultrathin Fibers and Their Antibacterial Food Packaging Applications

The purpose of this work is to develop a novel ultrathin fibrous membrane with a core-sheath structure as antibacterial food packaging film. Coaxial electrospinning was exploited to create the core-sheath structure, by which the delivery regulation of the active substance was achieved. Resveratrol (RE) and silver nanoparticles (AgNPs) were loaded into electrospun zein/polyethylene oxide ultrathin fibers to ensure a synergistic antibacterial performance. Under the assessments of a scanning electron microscope and transmission electron microscope, the ultrathin fiber was demonstrated to have a fine linear morphology, smooth surface and obvious core-sheath structure. X-ray diffraction and Fourier transform infrared analyses showed that RE and AgNPs coexisted in the ultrathin fibers and had good compatibility with the polymeric matrices. The water contact angle experiments were conducted to evaluate the hydrophilicity and hygroscopicity of the fibers. In vitro dissolution tests revealed that RE was released in a sustained manner. In the antibacterial experiments against Staphylococcus aureus and Escherichia coli, the diameters of the inhibition zone of the fiber were 8.89 ± 0.09 mm and 7.26 ± 0.10 mm, respectively. Finally, cherry tomatoes were selected as the packaging object and packed with fiber films. In a practical application, the fiber films effectively reduced the bacteria and decreased the quality loss of cherry tomatoes, thereby prolonging the fresh-keeping period of cherry tomatoes to 12 days. Following the protocols reported here, many new food packaging films can be similarly developed in the future.

Electrospun Nanofibers: Current Progress and Applications in Food Systems

Electrospinning has the advantages of simple manufacturing equipment, a low spinning cost, wide range of spinnable materials, and a controllable mild process, which can continuously fabricate submicron or nanoscale ultrafine polymer fibers without high temperature or high pressure. The obtained nanofibrous films may have a large specific surface area, unique pore structure, and easy-to-modify surface characteristics. This review briefly introduces the types and fiber structures of electrospinning and summarizes the applications of electrospinning for food production (e.g., delivery systems for functional food, filtration of beverages), food packaging (e.g., intelligent packaging, antibacterial packaging, antioxidant packaging), and food analysis (e.g., pathogen detection, antibiotic detection, pesticide residue detection, food compositions analysis), focusing on the advantages of electrospinning applications in food systems. Furthermore, the limitations and future research directions of the technique are discussed.

Nanoencapsulation of Essential Oils as Natural Food Antimicrobial Agents: An Overview

The global demand for safe and healthy food with minimal synthetic preservatives is continuously increasing. Natural food antimicrobials and especially essential oils (EOs) possess strong antimicrobial activities that could play a remarkable role as a novel source of food preservatives. Despite the excellent efficacy of EOs, they have not been widely used in the food industry due to some major intrinsic barriers, such as low water solubility, bioavailability, volatility, and stability in food systems. Recent advances in nanotechnology have the potential to address these existing barriers in order to use EOs as preservatives in food systems at low doses. Thus, in this review, we explored the latest advances of using natural actives as antimicrobial agents and the different strategies for nanoencapsulation used for this purpose. The state of the art concerning the antibacterial properties of EOs will be summarized, and the main latest applications of nanoencapsulated antimicrobial agents in food systems will be presented. This review should help researchers to better choose the most suitable encapsulation techniques and materials.

Spray drying encapsulation of bioactive compounds within protein-based carriers; different options and applications

Spray-drying is known as a common and economical technique for the encapsulation of various nutrients and bioactive compounds. However, shear and thermal tensions during atomization and dehydration, as well as physicochemical instability during storage, result in a loss of these compounds. As a solution, bioactives are stabilized into different carriers, among which proteins and peptides are of particular importance due to their functional properties, surface activity, and film/shell formability around particles. Given the importance of stabilization of bioactive compounds during spray drying, this paper focuses on the role of composition and type of carriers, as well as the characteristics and efficiency of various protein-based carriers in the encapsulation and maintaining of physicochemical, structural, and functional properties, along with biological activity of bioactive compounds (e.g., oleoresins, sterols, polyphenols, anthocyanins, carotenoids, probiotics, and peptides), and nutrients (e.g., vitamins, fatty acids and minerals) alone or in combination with other biopolymers.

Nanoencapsulation of unsaturated omega-3 fatty acids as protection against oxidation: A systematic review and data-mining

The chemical structure of unsaturated fatty acids makes them highly prone to oxidation, which decreases their nutritional properties. Nanocarriers have the ability to protect unstable nutraceuticals and take them to their specific targets. Thus, the aim is to determine the effectiveness of nanoencapsulation of omega-3 unsaturated fatty acids as protection against oxidation, as well as to apply data-mining approach to identify nanoencapsulation profiles. Three databases were used to search for studies focused on comparing omega-3 encapsulation to the active compound in its raw form. Studies without oxidation test or no use omega 3-rich oil as active ingredient in nanoformulations were excluded. Twenty-three studies were included in the systematic review. The qualitative analysis indicated that the main evaluated parameters were encapsulation efficiency (%), physical-chemical parameters and oxidation (analyzed at different storage temperatures), oil type, and whether the formulation was added to food. With regard to quantitative analysis, studies that did not perform oxidation tests focused on comparing free oil to the encapsulated one were excluded. Data-mining indicated that encapsulation efficiency and particle size were the main characteristic defining nanocarrier's effectiveness in protecting the oil against oxidation. Nevertheless, it is important to note the main characteristics associated with oil protection in nanocarriers.

Arthrospira platensis transglutaminase derived antioxidant peptide-packed electrospun chitosan/ poly (vinyl alcohol) nanofibrous mat accelerates wound healing, in vitro, via inducing mouse embryonic fibroblast proliferation

In this present study, we have carried out the antioxidant function of transglutaminase (TG) identified from Arthrospira platensis (Ap) transcriptome. The antioxidant peptide ML11 (MLRSIGIPARL) has been predicted from the transglutaminase core domain and the peptide's free radical scavenging potential was evaluated and it shows that it functions on a dose dependent manner. The ML11 peptide cell toxicity was analysed in the human blood leucocytes which resulted no cytotoxic activity in any of the cell population. Moreover, the nanofibre mat encapsulated with antioxidant peptide ML11 was prepared by electrospinning technique. The antioxidant peptide ML11 encapsulated mat showed increase in fibre diameter compared to the chitosan polyvinyl alcohol blended mat. The change in the crystalline behaviour of both chitosan and polyvinyl alcohol polymer to the amorphous nature was determined by X-ray diffraction at the broad band between 20 and 30° (2θ°). FTIR revealed the functional groups which present in the polymer as well as the interaction between their components of chitosan (CS) and polyvinyl alcohol (PVA). The fibre retains the antioxidant activity due to the peptide encapsulated by scavenging the intracellular ROS that was confirmed by flowcytometry and fluorescence microscopy. The ML11 peptide encapsulated mat showed no cytotoxicity in the NIH-3T3 mouse embryonic fibroblast cells. Also, ML11 peptide encapsulated fibre showed potential wound healing activity in NIH-3T3 cells. Taken altogether, the study indicates that the wound healing potential of the ML11 peptide encapsulated nano fibre mat may be used as biopharmaceutical drug.

Nanoencapsulation of carotenoids extracted from tomato peels into zein fibers by electrospinning

BACKGROUND

The processing of tomatoes generates significant amounts of tomato waste, which has a high potential to be used in food industry as a natural food colorant, antioxidant, and food supplement providing health benefits. However, it is difficult to incorporate the carotenoids into different food formulations because they are relatively unstable in food systems. Hence, this novel study investigated the use of an electrospinning technique for the encapsulation of carotenoids extracted from tomato peel into zein nanofibers to improve its thermal and storage stability, and antioxidant activity.

RESULTS

Composite zein nanofibers containing the carotenoids extracted from tomato peel (TP) were successfully produced with above 90% encapsulation efficiency by electrospinning. Scanning electron microscope (SEM) analysis revealed that the extract-loaded fibers exhibited morphology similar to the neat zein fibers with a bead-free, smooth, and homogeneously-distributed morphology. Differential scanning calorimetry (DSC) thermograms showed that the thermal stability of the extract was enhanced by nanoencapsulation. No significant changes in the Fourier transform infrared (FTIR) spectra of extract-loaded zein fibers were observed compared to neat zein fiber, showing that the TP extract could be entrapped into the zein fibers. Compared to non-encapsulated extract, the encapsulated one inside zein fibers had better retention of lycopene and antioxidant activity (AA) during 14-days' storage. More interestingly, the AA of the extract increased about 11-fold by nanoencapsulation.

CONCLUSION

This study showed that nanoencapsulation by electrospinning is an effective way to stabilize carotenoids, which is promising for their use in food processing. © 2018 Society of Chemical Industry.

Active Food Packaging Coatings Based on Hybrid Electrospun Gliadin Nanofibers Containing Ferulic Acid/Hydroxypropyl-Beta-Cyclodextrin Inclusion Complexes

In this work, hybrid gliadin electrospun fibers containing inclusion complexes of ferulic acid (FA) with hydroxypropyl-beta-cyclodextrins (FA/HP-β-CD-IC) were prepared as a strategy to increase the stability and solubility of the antioxidant FA. Inclusion complex formation between FA and HP-β-CD was confirmed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), and X-ray diffraction (XRD). After adjusting the electrospinning conditions, beaded-free fibers of gliadin incorporating FA/HP-β-CD-IC with average fiber diameters ranging from 269.91 ± 73.53 to 271.68 ± 72.76 nm were obtained. Control gliadin fibers containing free FA were also produced for comparison purposes. The incorporation of FA within the cyclodextrin molecules resulted in increased thermal stability of the antioxidant compound. Moreover, formation of the inclusion complexes also enhanced the FA photostability, as after exposing the electrospun fibers to UV light during 60 min, photodegradation of the compound was reduced in more than 30%. Moreover, a slower degradation rate was also observed when compared to the fibers containing the free FA. Results from the release into two food simulants (ethanol 10% and acetic acid 3%) and PBS also demonstrated that the formation of the inclusion complexes successfully resulted in improved solubility, as reflected from the faster and greater release of the compounds in the three assayed media. Moreover, in both types of hybrid fibers, the antioxidant capacity of FA was kept, thus confirming the suitability of electrospinning for the encapsulation of sensitive compounds, giving raise to nanostructures with potential as active packaging structures or delivery systems of use in pharmaceutical or biomedical applications.

Improved Viability and Thermal Stability of the Probiotics Encapsulated in a Novel Electrospun Fiber Mat

For the enhancement of the probiotics' survivability, a nanostructured fiber mat was developed by electrospinning. The probiotic Lactobacillus plantarum was encapsulated in the nanofibers with fructooligosaccharides (FOS) as the cell material. Fluorescence microscope image and scanning electron microscopy (SEM) showed that viable cells were successfully encapsulated in nanofibers (mean diameter = 410 ± 150 nm), and the applied voltage had no significant influence on their viability ( P > 0.05). A significantly improved viability (1.1 log) was achieved by incorporating 2.5% (w/w) of FOS as the electrospinning material ( P < 0.001). Additionally, compared with free cells, the survivability of cells encapsulated in electrospun FOS/PVA/ L. plantarum nanofibers was significantly enhanced under moist heat treatment (60 and 70 °C). This study shows that the obtained nanofiber is a feasible entrapment structure to improve the viability and thermal stability of encapsulated probiotic cells and provides an alternative approach for the development of functional food.