Zein as a water insoluble excipient for spray dry encapsulation of hydrophilic bioactives

Self-Assembly Behavior of Zein on Two Different Substrates Visualized by Atomic Force Microscopy

When protein molecules come into contact with different types of substrate materials, the surface properties of the substrate will have a significant effect on their self-assembly behavior. The purpose of this study was to investigate the self-assembly behavior of zein molecules on the two different substrates. Herein, the microstructure of zein molecules on the surface of two typical substrates, mica and glass, were characterized in detail by atomic force microscopy. It was found that zein molecules self-assemble to form spherical structures with uniform size and close arrangement on mica substrates. Compared with mica, the rough glass surface possesses a larger water contact angle, which leads to weaker interaction between zein molecules and its surface, thus enhancing the interaction between zein molecules. Therefore, the zein molecules on the glass substrate exhibit a distinct hierarchical arrangement of one large globule surrounded by many smaller ones. This work provides valuable information for further study of the self-assembly behavior of zein molecules on the substrate surface.

Nanobased Natural Polymers as a Carrier System for Glyphosate: An Interesting Approach Aimed at Sustainable Agriculture

Polymer-based herbicide nanocarriers have shown potential for increasing the herbicide efficacy and environmental safety. This study aimed to develop, characterize, and evaluate toxicity to target and nontarget organisms of natural-based polymeric nanosystems for glyphosate. Polymers such as chitosan (CS), zein (ZN), and lignin (LG) were used in the synthesis. Nanosystem size, surface charge, polydispersity index, encapsulation efficiency, toxicity to weed species (Amaranthus hybridus, Ipomoea grandifolia, and Eleusine indica), and Roundup Ready (RR) crops, soil respiration, and enzyme activity were evaluated. The most stable system was the combination of ZN with the cross-linker poloxamer (PL), with higher weed control efficacy (90-96%) for A. hybridus, compared to commercial glyphosate (40%). No improvement was observed for I. grandifolia and E. indica. No glyphosate toxicity was observed in RR crops, soil respiration, or soil enzymes, indicating no toxic effects of the nanoformulation in these models. ZN-PL systems can be a promising alternative for glyphosate delivery, using environmentally friendly materials, with improved efficiency for weed control in agriculture.

Pickering emulsions stabilized by prolamin-based proteins as innovative carriers of bioactive compounds

Pickering emulsions (PEs) can be used as efficient carriers for encapsulation and controlled release of different bioactive compounds. Recent research has revealed the potential of prolamins in development of nanoparticle- and emulsion-based carriers which can improve the stability and bioavailability of bioactive compounds. Prolamin-based particles have been effectively used as stabilizers of various PEs including single PEs, high internal phase PEs, multiple PEs, novel triphasic PEs, and PE gels due to their tunable self-assembly behaviors. Prolamin particles can be fabricated via different techniques including anti-solvent precipitation, dissolution followed by pH adjustment, heating, and ion induced aggregation. Particles fabricated from prolamins alone or in combination with other hydrocolloids or polyphenols have also been used for stabilization of different PEs which were shown to be effective carriers for food bioactives, providing improved stability and functionality. This article covers the recent advances in various PEs stabilized by prolamin particles as innovative carriers for bioactive ingredients. Strategies applied for fabrication of prolamin particles and prolamin-based carriers are discussed. Emerging techno-functional applications of prolamin-based PEs and possible challenges are also highlighted.

The application of encapsulation technology in the food Industry: Classifications, recent Advances, and perspectives

Encapsulation technology has been extensively used to enhance the stability, specificity, and bioavailability of essential food ingredients. Additionally, it plays a vital role in improving product quality and reducing production costs. This study presents a comprehensive classification of encapsulation techniques based on the state of different cores (solid, liquid, and gaseous) and offers a detailed description and analysis of these encapsulation methods. Specifically, it introduces the diverse applications of encapsulation technology in food, encompassing areas such as antioxidant, protein activity, physical stability, controlled release, delivery, antibacterial, and probiotics. The potential impact of encapsulation technology is expected to make encapsulation technology a major process and research hotspot in the food industry. Future research directions include applications of encapsulation for enzymes, microencapsulation of biosensors, and novel technologies such as self-assembly. This study provides a valuable theoretical reference for the in-depth research and wide application of encapsulation technology in the food industry.

Zein-Based Nanoparticles as Active Platforms for Sustainable Applications: Recent Advances and Perspectives

Nanomaterials, due to their unique structural and functional features, are widely investigated for potential applications in a wide range of industrial sectors. In this context, protein-based nanoparticles, given proteins' abundance, non-toxicity, and stability, offer a promising and sustainable methodology for encapsulation and protection, and can be used in engineered nanocarriers that are capable of releasing active compounds on demand. Zein is a plant-based protein extracted from corn, and it is biocompatible, biodegradable, and amphiphilic. Several approaches and technologies are currently involved in zein-based nanoparticle preparation, such as antisolvent precipitation, spray drying, supercritical processes, coacervation, and emulsion procedures. Thanks to their peculiar characteristics, zein-based nanoparticles are widely used as nanocarriers of active compounds in targeted application fields such as drug delivery, bioimaging, or soft tissue engineering, as reported by others. The main goal of this review is to investigate the use of zein-based nanocarriers for different advanced applications including food/food packaging, cosmetics, and agriculture, which are attracting researchers' efforts, and to exploit the future potential development of zein NPs in the field of cultural heritage, which is still relatively unexplored. Moreover, the presented overview focuses on several preparation methods (i.e., antisolvent processes, spry drying), correlating the different analyzed methodologies to NPs' structural and functional properties and their capability to act as carriers of bioactive compounds, both to preserve their activity and to tune their release in specific working conditions.

Synergetic-effect-enhanced electrochemiluminescence of zein-protected Au-Ag bimetallic nanoclusters for CA15-3 detection

In this work, a sandwich-type electrochemiluminescence (ECL) system was constructed for the detection of CA15-3. Gold-silver bimetallic nanoclusters (Au-Ag BNCs) with zein as a protective ligand were synthesized, and the excellent ECL performance of this material was demonstrated for the first time. Zein carrying a variety of groups that ligated with Au-Ag BNCs, forming a protective shell of zein, effectively prevented clusters from aggregating or growing into larger nanoparticles. The synergistic effect of the bimetal promotes the ECL emission, making this nanoscale material an ideal ECL probe. GO-PANI, which effectively promoting the production of sulfate radicals of the co-reactant and significantly increasing the ECL strength, was a good sensing platform for antibody immobilization. Consequently, we constructed an ECL sensor with GO-PANI as the sensing platform and Au-Ag BNCs@zein as the ECL probe, with a detection range of 0.001-100 U mL-1 and a detection limit of 0.0003 U mL-1, provided a strong support for the sensor for future CA15-3 detection applications.

Encapsulation of Rosemary Extracts using High Voltage Electrical Discharge in Calcium Alginate/Zein/Hydroxypropyl Methylcellulose Microparticles

The increased demand for functional food with added health benefits is directing industrial procedures toward more sustainable production of naturally added bioactive compounds. The objective of this research was to investigate the potential of bioactive compounds from rosemary extract obtained using high-voltage electrical discharge as a green extraction method, for microencapsulation as a protective method for future application in functional food. Four types of microparticles were made via the ionic gelation method using alginate (Alg), zein (Z), and hydroxypropyl methylcellulose (HPMC) biopolymers and were analyzed considering the physicochemical properties. The diameter of dry microparticles ranged from 651.29 to 1087.37 μm. The shape and morphology analysis of microparticles showed that the obtained microparticles were quite spherical with a granular surface. The high encapsulation efficiency was obtained with a loading capacity of polyphenols up to 11.31 ± 1.47 mg GAE/g (Alg/Z microparticles). The microencapsulation method showed protective effects for rosemary polyphenols against pH changes during digestion. Specifically, the addition of both zein and HPMC to calcium-alginate resulted in microparticles with a prolonged release for better availability of polyphenols in the intestine. This research background indicates that the release of rosemary extract is highly dependent on the initial biopolymer composition with high potential for further functional food applications.

Simple and complex coacervation methods for the nanoencapsulation of Rosa damascena mill L. anthocyanin in zein/potato starch: A new approach to enhance antioxidant and thermal properties

The structure and antioxidant properties of zein and potato starches as well as the stability of anthocyanins strongly depend on the pH. However, due to the stability of anthocyanins in at acidic medium, their encapsulation has been limited to low pHs. In the present work, an encapsulation of anthocyanins extracted from Rosa damascena mill L. (as a model) into zein, starch, and their binary mixtures by simple and complex coacervation methods over a wide range of pH (especially higher pHs), and different encapsulating agent doses and different initial volumes of anthocyanin were studied in order to obtain new conditions for the preservation of anthocyanins and to improve the antioxidant activities of zein and potato starches. High levels of antioxidant activity and encapsulation efficiency for zein/starch/anthocyanin nanocapsules and maximum antioxidant activity for zein/starch nanocapsules (without anthocyanin) were obtained at pHs 8 and 2, respectively. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray powder diffraction, and thermal gravimetric analysis techniques were used to analyze simple and complex coacervates biopolymer interactions, morphology, and thermal stability. The size of zein nanocapsules (283-366 nm) decreased in the range of 50-175 nm after the encapsulation of anthocyanin (pH 8), which makes them suitable for drug delivery processes. The prepared nanocapsules showed a high scavenging ability.

Recent Developments in the Microencapsulation of Fish Oil and Natural Extracts: Procedure, Quality Evaluation and Food Enrichment

Due to the beneficial health effects of omega-3 fatty acids and antioxidants and their limited stability in response to environmental and processing factors, there is an increasing interest in microencapsulating them to improve their stability. However, despite recent developments in the field, no specific review focusing on these topics has been published in the last few years. This work aimed to review the most recent developments in the microencapsulation of fish oil and natural antioxidant compounds. The impact of the wall material and the procedures on the quality of the microencapsulates were preferably evaluated, while their addition to foods has only been studied in a few works. The homogenization technique, the wall-material ratio and the microencapsulation technique were also extensively studied. Microcapsules were mainly analyzed for size, microencapsulation efficiency, morphology and moisture, while in vitro digestion, flowing properties, yield percentage and Fourier transform infrared spectroscopy (FTIR) were used more sparingly. Findings highlighted the importance of optimizing the most influential variables of the microencapsulation procedure. Further studies should focus on extending the range of analytical techniques upon which the optimization of microcapsules is based and on addressing the consequences of the addition of microcapsules to food products.

Influence of Various Model Compounds on the Rheological Properties of Zein-Based Gels

The controlled release of a compound entrapped in a biocompatible formulation is a sought-after goal in modern pharmaceutical technology. Zein is a hydrophobic protein which has several advantageous properties that make it suitable for use as a biocompatible and degradable material under physiological conditions. It is, therefore, proposed for different biomedical and pharmaceutical applications. In particular, due to its gelling properties, it can be used to form a polymeric network able to preserve biomolecules from harsh environments. The current study was designed to investigate the influence of different probes on the rheological properties of gels made up of zein, in order to characterize the systems as a function of the polymer concentration. Four model compounds characterized by different physico-chemical properties were entrapped in zein gels, and different behaviors (viscoelastic or pronounced solid-like characteristics) of the systems were observed. Zein-based gels showed various release profiles of the encapsulated compounds, suggesting that there are different interaction rates between the probes and the polymeric matrix.