Enhanced Physicochemical Stability of β-Carotene Emulsions Stabilized by β-Lactoglobulin-Ferulic Acid-Chitosan Ternary Conjugate

Fabrication of high-preformance emulsifier from conjugating maltodextrin onto myofibrillar protein peptide with microwave- ultrasound synergy

In this study, we systematically investigated the emulsifying capabilities of myofibrillar protein (MP)- and MP peptide (MPP)-based conjugates synthesized through intensification techniques: water bath (WB), microwave, ultrasound, and the combined ultrasound-microwave (UM) methods. Compared with WB, microwave, and ultrasound treatments, the combined UM treatment greatly promoted the glycation reaction because ultrasound and microwave mutually reinforced modification effects. The resultant conjugate structure tended to unfold with more flexible conformation and homogeneous morphology. Moreover, the emulsifying properties of conjugates developed with single and combined ultrasound-assisted glycation displayed substantial improvement, and pre-hydrolysis further enhanced these performances, as observed in the Principal Component Analysis as well. Remarkably, MPP grafted by maltodextrin with the assistance of a combined UM field produced the smallest and most uniform emulsion system, positioning it as the most efficient emulsifier among all the fabricated glycoconjugates. Our study highlighted the potential of synergistically applying ultrasound and microwave techniques to develop a well-performance glycation with an ideal conjugate structure, in which they would be associated into a strong film that provided the robust physical barrier, creaming stability, heat retention, and oxidation resistance. These findings offered a basis for better utilizing complex ultrasonic technology to develop novel and improved MP-based food products.

Construction of protein-, polysaccharide- and polyphenol-based conjugates as delivery systems

Natural polymers, such as polysaccharides and proteins, have been used to prepare several delivery systems owing to their abundance, bioactivity, and biodegradability. They are usually modified or combined with small molecules to form the delivery systems needed to meet different needs in food systems. This paper reviews the interactions of proteins, polysaccharides, and polyphenols in the bulk phase and discusses the design strategies, coupling techniques, and their applications as conjugates in emulsion delivery systems, including traditional, Pickering, multilayer, and high internal-phase emulsions. Furthermore, it explores the prospects of the application of conjugates in food preservation, food development, and nanocarrier development. Currently, there are seven methods for composite delivery systems including the Maillard reaction, carbodiimide cross-linking, alkali treatment, enzymatic cross-linking, free radical induction, genipin cross-linking, and Schiff base chemical cross-linking to prepare binary and ternary conjugates of proteins, polysaccharides, and polyphenols. To design an effective target complex and its delivery system, it is helpful to understand the physicochemical properties of these biomolecules and their interactions in the bulk phase. This review summarizes the knowledge on the interaction of biological complexes in the bulk phase, preparation methods, and the preparation of stable emulsion delivery system.

Research progress on chitin/chitosan-based emulsion delivery systems and their application in lipid digestion regulation

Excessive lipid intake is linked to an elevated risk of health problems. However, reducing lipid contents may influence food structure and flavor. Some alternatives are needed to control the lipid absorption. Emulsions are common carriers for lipids, which can control the hydrolysis and absorption of lipids. Chitin (Ch) and chitosan (CS) are natural polysaccharides with good biodegradability, biocompatibility, and unique cationic properties. They have been reported to be able to delay lipolysis, which can be regarded as one of the most promising agents that regulates lipid digestion (LiD). The application of Ch/CS and their derivatives in emulsions are summarized in this review with a focus on their performances and mechanisms for LiD regulation, aiming to provide theoretical guidance for the development of novel Ch/CS emulsions, and the regulation of LiD. A reasonable design of emulsion interface can provide its resistance to the external environment and then control LiD. The properties of emulsion interface are the key factors affecting LiD. Therefore, systematic study on the relationship between Ch/CS-based emulsion structure and LiD can not only instruct the reasonable design of emulsion interface to accurately regulate LiD, but also provide scientific guidelines for applying Ch/CS in functional food, medicine and other fields.

Effect of ferulic acid covalent conjugation on the functional properties and antigenicity of β-lactoglobulin

Binding to phenolics can improve the functional properties of proteins. Changes in structure, functional properties, and antigenicity of β-lactoglobulin (β-LG) after covalent conjugation with ferulic acid (FA) at different mass ratios were reported here. The results of SDS-PAGE and gel exclusion chromatography confirmed that covalent complexes were formed. When the mass ratio of β-LG and FA was 10:6, the binding content of FA was the highest. Fluorescence spectroscopy, UV-visible absorption spectrometry, and FTIR analysis showed that the structure of the complexes was more stretched compared to native β-LG. The addition of FA significantly improved the emulsifying property of β-LG. When the mass ratio was 10:6, the radical scavenging activities of DPPH and ABTS reached 65.06% and 88.22%, respectively, and the antigenicity of β-LG reduced by about 35%. This study provides novel β-LG-FA complexes in food systems to reduce the antigenicity of β-LG and improve functional properties.

Progress in the Application of Food-Grade Emulsions

The detailed investigation of food-grade emulsions, which possess considerable structural and functional advantages, remains ongoing to enhance our understanding of these dispersion systems and to expand their application scope. This work reviews the applications of food-grade emulsions on the dispersed phase, interface structure, and macroscopic scales; further, it discusses the corresponding factors of influence, the selection and design of food dispersion systems, and the expansion of their application scope. Specifically, applications on the dispersed-phase scale mainly include delivery by soft matter carriers and auxiliary extraction/separation, while applications on the scale of the interface structure involve biphasic systems for enzymatic catalysis and systems that can influence substance digestion/absorption, washing, and disinfection. Future research on these scales should therefore focus on surface-active substances, real interface structure compositions, and the design of interface layers with antioxidant properties. By contrast, applications on the macroscopic scale mainly include the design of soft materials for structured food, in addition to various material applications and other emerging uses. In this case, future research should focus on the interactions between emulsion systems and food ingredients, the effects of food process engineering, safety, nutrition, and metabolism. Considering the ongoing research in this field, we believe that this review will be useful for researchers aiming to explore the applications of food-grade emulsions.

Recent advances on formation mechanism and functionality of chitosan-based conjugates and their application in o/w emulsion systems: A review

Chitosan is very attractive in the food industry due to its good biocompatibility and high biodegradability. In particular, it can be used as a preferred material for the fabrication of stabilizers in emulsion-based foods. However, poor solubility and antioxidant activity limit its wide application. The functionality of chitosan can be extended by forming chitosan-based conjugates, which can be used to modulate the characteristics of the oil-water interface, thereby improving the stability and performance of the o/w emulsions. This review highlights the recent progress of chitosan-based conjugates, focusing on the classification, formation mechanism and functional properties, and the applications of these conjugates in o/w emulsions are summarized. Lastly, the promising research trends and challenges of chitosan-based conjugates and their emulsion systems in this field are also discussed. This review will provide a theoretical basis for the wide application of chitosan-based conjugates in emulsion systems.

High Internal Phase Emulsions Stabilized with Polyphenol-Amyloid Fibril Supramolecules for Encapsulation and Protection of Lutein

High internal phase emulsions (HIPEs), also called highly concentrated emulsions with a minimal internal phase volume fraction of 74%, have been paid increasing attention in the development of functional foods due to their high potential in loading with large amounts of hydrophobic nutriceuticals. In the present study, HIPEs stabilized by polyphenol-amyloid supramolecular filaments were prepared for encapsulation of olive oil and loading with lutein. Binding and stacking of the green tea polyphenol epigallocatechin gallate (EGCG) on the surface of amyloid fibrils fabricated from hen egg lysozyme resulted in the hybrid supramolecules, which assembled to form hydrogels. The amyloid fibril clusters shrouded by EGCG were observed in the microstructure of the hydrogels characterized by atomic force microscopy (AFM). HIPEs stabilized by the EGCG-amyloid fibril supramolecules showed the typical microstructure of highly packed polyhedral geometric oil droplets. The gel strength of the HIPEs stabilized by the hybrid supramolecules was greater than that of HIPEs stabilized by pure amyloid fibrils. The droplet size of the HIPEs first decreased and then increased with the increase of EGCG contents in the hybrid supramolecules, which was consistent with the corresponding emulsion morphologies obtained from the images of confocal laser scanning microscopy (CLSM). Aggregation of the protein-based nanofibrils appeared in the continuous phase at higher EGCG contents. The droplet size of the HIPEs decreased with the increase of the amyloid fibril concentration, accompanied by more packed and homogenously dispersed lipid droplets, as shown in the CLSM images. A high loading content of lutein of up to 10 mg/mL in the prepared HIPEs was realized, and the stability of lutein against ultraviolet irradiation, heat, iron, and hydrogen peroxide was promoted significantly. In addition, encapsulation with the HIPEs prevented the oxidization of olive oil, and this effect was enhanced with the increase of the EGCG content in the hybrid supramolecules ranging from 0 to 0.25 wt %. The protection function of the HIPEs might be ascribed to the membrane of interfacial amyloid fibrils and the crowded oil droplet environment, both of which could shield the pro-oxidation factors.

Exploration of the Microstructure and Rheological Properties of Sodium Alginate-Pectin-Whey Protein Isolate Stabilized Β-Carotene Emulsions: To Improve Stability and Achieve Gastrointestinal Sustained Release

Sodium alginate (SA)-pectin (PEC)-whey protein isolate (WPI) complexes were used as an emulsifier to prepare β-carotene emulsions, and the encapsulation efficiency for β-carotene was up to 93.08%. The confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) images showed that the SA-PEC-WPI emulsion had a compact network structure. The SA-PEC-WPI emulsion exhibited shear-thinning behavior and was in a semi-dilute or weak network state. The SA-PEC-WPI stabilized β-carotene emulsion had better thermal, physical and chemical stability. A small amount of β-carotene (19.46 ± 1.33%) was released from SA-PEC-WPI stabilized β-carotene emulsion in simulated gastric digestion, while a large amount of β-carotene (90.33 ± 1.58%) was released in simulated intestinal digestion. Fourier transform infrared (FTIR) experiments indicated that the formation of SA-PEC-WPI stabilized β-carotene emulsion was attributed to the electrostatic and hydrogen bonding interactions between WPI and SA or PEC, and the hydrophobic interactions between β-carotene and WPI. These results can facilitate the design of polysaccharide-protein stabilized emulsions with high encapsulation efficiency and stability for nutraceutical delivery in food and supplement products.