Cyclodextrins and their potential applications for delivering vitamins, iron, and iodine for improving micronutrient status

Cyclodextrins (CDs) have been investigated as potential biopolymeric carriers that can form inclusion complexes with numerous bioactive ingredients. The inclusion of micronutrients (e.g. vitamins or minerals) into cyclodextrins can enhance their solubility and provide oxidative or thermal stability. It also enables the formulation of products with extended shelf-life. The designed delivery systems with CDs and their inclusion complexes including electrospun nanofibers, emulsions, liposomes, and hydrogels, show potential in enhancing the solubility and oxidative stability of micronutrients while enabling their controlled and sustained release in applications including food packaging, fortified foods and dietary supplements. Nano or micrometer-sized delivery systems capable of controlling burst release and permeation, or moderating skin hydration have been reported, which can facilitate the formulation of several personal and skin care products for topical or transdermal delivery of micronutrients. This review highlights recent developments in the application of CDs for the delivery of micronutrients, i.e. vitamins, iron, and iodine, which play key roles in the human body, emphasizing their existing and potential applications in the food, pharmaceuticals, and cosmeceuticals industries.

Preparation and characterization of an iron-β-cyclodextrin inclusion complex: factors influencing the host-guest interaction

Cyclodextrins have received attention recently due to their superior binding with countless hydrophobic molecules. The host-guest interaction between the cyclodextrin cavity and the hydrophobic component not only facilitates the formation of a strong inclusion complex (IC), but also improves its stability against thermal degradation. The functionality of cyclodextrins for the delivery of hydrophilic components is less explored in comparison. This study discusses the application of β-cyclodextrin (βCD) for the delivery of highly bioavailable and hydrophilic iron, ferric sodium EDTA, which exhibits great functionality in the presence of polyphenols and phytates with potential application in food fortification. The formation of IC was dependent on the cyclodextrin amount and alcoholic co-solvent and was influenced by the stirring duration. For ferric sodium EDTA, the highest inclusion rate (IR) of ∼77% was obtained after 72 hours of mixing in 25.4% (v/v) alcohol at a ratio of iron : βCD of 1 : 6. A higher IR (∼96%) was obtained after 6 hours of stirring with less soluble ferrous ammonium phosphate in comparison. The melting temperature (T_m) of the ferrous ammonium phosphate complex increased from ∼172 to ∼294 °C. The high IR and enhanced thermal resistance of the complex make βCDs potential carriers for ferrous ammonium phosphate delivery and fortification of foods processed at high temperatures.

Curcumin, a potent therapeutic nutraceutical and its enhanced delivery and bioaccessibility by pickering emulsions

Curcumin is a biomolecule with functional moieties, which contribute to its anti-inflammatory, anticancer, and antioxidant properties. It has shown several therapeutic effects on treating inflammatory and neurodegenerative diseases and contributes to the reduction of oxidative stress and damage to body tissues. However, its low solubility and fast metabolism limit its absorption in the gastrointestinal (GI) tract and lead to its low bioavailability. Preparation of Pickering emulsions stabilized with mineral or biopolymer-based nanoparticles can be an effective strategy for enhancing the stability of curcumin against degradation, increasing its bioaccessibility in the GI tract, and achieving its controlled release at various locations based on changes in environmental conditions. Various nanoparticles prepared from minerals, proteins, and polysaccharides show potential for stabilizing the curcumin-loaded emulsions, and their wettability can be altered through complexation and formation of hybrid nanoparticles. Stabilization of Pickering emulsions with polysaccharide-based nanoparticles and their complexes can enhance the stability of the curcumin against degradation. Moreover, various protein-based nanoparticles and their conjugated forms with other proteins or polysaccharides can enable the preparation of high internal phase Pickering emulsions (HIPEs) with concomitant higher loading and bioaccessibility of the curcumin molecule. In light of the several therapeutic properties of curcumin, this review article aims to highlight recent studies and the strategies used for the preparation of curcumin Pickering emulsions stabilized by various nanoparticles for enhancing its bioaccessibility during metabolism. These may be useful in pharmaceutical and food industries for drug development and delivery and fortification of food products with this nutraceutical component.