Abstract
This review explores the extensive literature on starch particle-stabilized Pickering emulsions for encapsulating bioactive compounds in food products. These emulsions offer superior stability and unique properties for delivering bioactive compounds (such as polyphenols, carotenoids, fatty acids, and vitamins) in food systems such as sauces, dairy products, and functional foods. Encapsulation preserves the bioactivity of these compounds and enhances targeted delivery, offering potential nutritional and health benefits. Starch, although naturally hydrophilic and requiring modifications to enhance its functionality, is gaining increasing attention as a particle for stabilizing Pickering emulsions in foods systems. Various modifications, including chemical and structural changes, affect the functionality of starch in emulsions. This review discusses the key factors influencing emulsion stabilization, including particle and oil characteristics, as well as production methods, such as mechanical techniques. Research on the encapsulation of bioactive compounds using starch-stabilized emulsions and methods for their characterization are also presented. This review further identifies areas requiring more research, including alternative particle modification techniques, emulsion responses to external stimuli (pH, temperature), interactions between bioactive compounds and particles, their effects on digestion and nutrition, and the production of double emulsions for enhanced bioactive compound delivery.
1. Introduction
Bioactive compounds are now recognized as nutraceuticals, which include compounds spanning a wide range of chemical structures, such as proteins, peptides, polysaccharides, fibers, fatty acids, and phenolics. However, several factors limit the application of bioactive compounds isolated from natural sources in food systems: (1) incompatibility with the food matrix; (2) rapid degradation during food processing; and (3) vulnerability to digestive activity in the biological system [1]. For example, hydrophobic compounds, such as flavonoids, have poor aqueous solubility, thus complicating their incorporation into foods. They are also susceptible to food processing conditions, where exposure to heat, light, and oxygen can significantly reduce their efficacy. Therefore, their encapsulation in an emulsion allows their incorporation into an aqueous food matrix, protects the bioactive compound, and allows absorption during digestion [2,3].
Pickering emulsions serve as effective systems for the encapsulation and delivery of bioactive compounds. These emulsions are stabilized by solid or colloidal particles that act as emulsifiers at the oil-water interface through steric hindrance [4]. Owing to their unique properties, such as high stability, combined with the use of natural particles that are multifunctional, biocompatible, nontoxic, and environmentally friendly, they are particularly suitable for applications in food matrices [5].
Natural particles can be obtained from renewable sources such as gelatin nanoparticles, cellulose nanoparticles, globular proteins, and starch nanoparticles [6]. Starch, as a natural food ingredient, has been successfully used in the preparation of Pickering emulsions after hydrophobic modification [2]. This interest derives from the fact that starch is considered GRAS (generally recognized as safe), nonallergenic, abundant, and low in cost [7].
Thus, this review evaluates the use of starch particle-stabilized Pickering emulsions for encapsulating functional and bioactive compounds in food matrices. This section discusses the role of starch as a food-grade stabilizer in these emulsions, outlining production methods and factors influencing their mechanical and physicochemical stability. Additionally, it describes the characterization techniques essential for analyzing these systems.
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Starch-Based Pickering Emulsions for Bioactive Compound Encapsulation: Production, Properties, and Applications
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Ramos, G.V.C.; Ramírez-López, S.; Pinho, S.C.d.; Ditchfield, C.; Moraes, I.C.F. Starch-Based Pickering Emulsions for Bioactive Compound Encapsulation: Production, Properties, and Applications. Processes 2025, 13, 342. https://doi.org/10.3390/pr13020342
