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BACKGROUND: Egg yolk granules (EYGs)‐soy lecithin (SL) complex is a newly developed delivery system that is effective for improving the storage stability of hydrophobic bioactive compounds. However, the formation mechanism of EYGs and SL complex and its effect on the gastrointestinal fate of lutein‐loaded emulsions needs to be investigated further. RESULTS: Adding SL greatly improved the surface activity of the EYGs, as evidenced by reduced surface tension and an increased adsorption rate to the oil/water interface. Hydrophobic interaction was the dominant force in the formation of EYG‐SL complex, with hydrogen and ionic bonds playing complementary roles. Using the EYG‐SL complex, stable oil‐in‐water emulsions were formed and exhibited an enhanced retention ratio and bioaccessibility of lutein after simulated digestion. Correlation analysis demonstrated that the additional anti‐oxidant activity as a result of EYGs was responsible for the high retention of lutein, whereas low surface tension facilitated the micellization of bioaccessible lutein. CONCLUSION: The present study shows that the EYG and SL have a synergistic effect with respect to improving the retention ratio and bioaccessibility of lutein in emulsions stabilized by EYG‐SL complex after digestion and this will guide the development of value‐added oil‐in‐water emulsion products using protein‐lecithin complex as a promising nutrient delivery vehicle. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Hen egg yolk (EY) has a variety of techno-functionalities, including emulsifying, gelling, and film-forming properties. However, the application of native EY and its fractions is still limited due to the insufficient functionalities. Thus, various modification treatments have been used to improve the functionalities. In addition, there has been increasing research interest to explore the potential of modified EY and its fractions for applications in developing value-added food products. This review provides a brief introduction of EY structures, fractions, and components and focuses on discussing a wide range of existing modification methods and the mechanism of each method to change the structure and improve the desirable functionality of EY and its fractions. Three emerging applications of EY in food formulation industry, i.e. nutrient encapsulation and delivery system, unmodified EY substitutes, and edible films, are finally highlighted. Recent studies have shown that pre-treatment of EY and its fractions are often needed using enzymatic hydrolysis, complexing with polysaccharides, or other chemical, physical, and fermentation methods. The purpose of the pre-treatment is to dissociate the aggregated EY protein state, modify solution characteristics (such as solubility, hydrophobicity, and surface charge), so that the functionality is greatly improved, leading to more stable emulsion systems or other novel EY-based food products. By reviewing the new modification technology and application trends of EY, this review provides expert opinions of future research directions for the development of value-added EY derived food products. • Modification techniques for the functional enhancement of egg yolk are summarized. • Egg yolk derived emulsions or micro-capsules are attractive delivery systems. • Low cholesterol egg yolk fractions are new alternatives for unmodified egg yolk. • Egg yolk components are important candidates in the preparation of edible films. [ABSTRACT FROM AUTHOR]

• Algal oil powder formulated by egg yolk granules-lecithin composite was developed. • Physical stability of the powder formulation upon redispersion was assessed. • The oxidative stability of algal oil powders was related with physical properties. • A synergistic stability enabled by dissociated EYGs and antioxidants was observed. This study reported a powder formulation containing omega-3-rich algal oil emulsions stabilized by egg yolk granules (EYGs)/lecithin composites. The improved physical stability of the algal oil samples due to increasing pH and lecithin addition was beneficial to the oxidative stability through analysis of free radical scavenging activities, metal ion chelating activities, and the release of primary and secondary oxidation products during accelerated storage (12 days, 60 °C). In addition, the effect of three antioxidants, i.e. ascorbic acid (VC), ascorbyl palmitate (AP), and α-tocopherol (VE), on lipid oxidation was investigated. Results showed that antioxidant partitioning at different regions of the emulsion system influenced its ability to prevent oxidation with the effectiveness of AP (at the O/W interface) > VE (in the oil phase) > VC (in the aqueous phase). This study developed a new powder-based emulsion formulation for algal oils with superior oxidative stability as an alternative source of omega-3. [ABSTRACT FROM AUTHOR]