Cyclodextrins: Structural, Chemical, and Physical Properties, and Applications

Due to their unique structural, physical and chemical properties, cyclodextrins and their derivatives have been of great interest to scientists and researchers in both academia and industry for over a century. Many of the industrial applications of cyclodextrins have arisen from their ability to encapsulate, either partially or fully, other molecules, especially organic compounds. Cyclodextrins are non-toxic oligopolymers of glucose that help to increase the solubility of organic compounds with poor aqueous solubility, can mask odors from foul-smelling compounds, and have been widely studied in the area of drug delivery. In this review, we explore the structural and chemical properties of cyclodextrins that give rise to this encapsulation (i.e., the formation of inclusion complexes) ability. This review is unique from others written on this subject because it provides powerful insights into factors that affect cyclodextrin encapsulation. It also examines these insights in great detail. Later, we provide an overview of some industrial applications of cyclodextrins, while emphasizing the role of encapsulation in these applications. We strongly believe that cyclodextrins will continue to garner interest from scientists for many years to come, and that novel applications of cyclodextrins have yet to be discovered.

Triggered and controlled release of active gaseous/volatile compounds for active packaging applications of agri-food products: A review

Gaseous and volatile active compounds are versatile to enhance safety and preserve quality of agri-food products during storage and distribution. However, the use of these compounds is limited by their high vapor pressure and/or chemical instability, especially in active packaging (AP) applications. Various approaches for stabilizing and controlling the release of active gaseous/volatile compounds have been developed, including encapsulation (e.g., into supramolecular matrices, polymer-based films, electrospun nonwovens) and triggered release systems involving precursor technology, thereby allowing their safe and effective use in AP applications. In this review, encapsulation technologies of gases (e.g., CO₂ , ClO₂ , SO₂ , ethylene, 1-methylcyclopropene) and volatiles (e.g., ethanol, ethyl formate, essential oils and their constituents) into different solid matrices, polymeric films, and electrospun nonwovens are reviewed, especially with regard to encapsulation mechanisms and controlled release properties. Recent developments on utilizing precursor compounds of bioactive gases/volatiles to enhance their storage stability and better control their release profiles are discussed. The potential applications of these controlled release systems in AP of agri-food products are presented as well.

Antioxidant activity of β-cyclodextrin inclusion complexes containing trans-cinnamaldehyde by DPPH, ABTS and FRAP

This study was carried out to observed β-cyclodextrin (β-CD) inclusion complexes containing trans-cinnamaldehyde (CIN) by using DPPH, ABTS and FRAP assay. Antioxidative ability was compared between pure CIN and β-CD-CIN inclusion complexes and particle size, encapsulation efficiency, and temperature-dependent release of inclusion complexes were investigated. High concentration of β-CD (1.8%) as well as guest oil 1:3 molar ratio (β-CD:CIN) influenced on particle size bigger during self-assembly process. And particle sizes were increased as storage period. In the antioxidant capacity results, pure β-CD (1.8%) was antioxidative without CIN especially at FRAP assay. Antioxidant activity dramatically increased after 1:1 molar ratio (1.8% β-CD:CIN), especially at DPPH assay and ABTS^•+ assay. In this study, β-CD complexation enhanced CIN solubility and affected increase the antioxidant activity of the CIN. Moreover, we need to consider that molar ratio of between β-CD concentration and CIN is effective manufacturing condition to improve antioxidant activity of β-CD-CIN inclusion complexes.