Zein Beta-Cyclodextrin Micropowders for Iron Bisglycinate Delivery

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.

Iron delivery systems for controlled release of iron and enhancement of iron absorption and bioavailability

Iron deficiency is a global nutritional problem, and adding iron salts directly to food will have certain side effects on the human body. Therefore, there is growing interest in food-grade iron delivery systems. This review provides an overview of iron delivery systems, with emphasis on the controlled release of iron during gastrointestinal digestion, as well as the enhancement of iron absorption and bioavailability. Iron-bearing proteins are easily degraded by digestive enzymes and absorbed through receptor-mediated endocytosis. Instead, protein aggregates are slowly degraded in the stomach, which delays iron release and serves as a potential iron supplement. Amino acids, peptides and polysaccharides can bind iron through iron binding sites, but the formed compounds are prone to dissociation in the stomach. Moreover, peptides and polysaccharides can deliver iron by mediating the formation of ferric oxyhydroxide which is absorbed through endocytosis or bivalent transporter 1. In addition, liposomes are unstable during gastric digestion and iron is released in large quantities. Complexes formed by polysaccharides and proteins, and microcapsules formed by polysaccharides can delay the release of iron in the gastric environment and prolong iron release in the intestinal environment. This review is conducive to the development of iron functional ingredients and dietary supplements.