Encapsulation of ethanol in cyclodextrin and bio-based cyclodextrin metal-organic framework for active packaging

Abstract

In the last two decades, various porous materials have been researched by the scientific community for diverse applications. Metal-organic frameworks (MOFs) belong to the class of microporous, high surface area crystalline materials synthesized by coordinating metal ions with organic linkers. MOFs can host various molecules in their pores, depending on their interaction. This host-guest chemistry can be utilized to sorb established active organic compounds such as ethanol, acetaldehyde, formaldehyde, cinnamaldehyde, thymol, etc. Extended release of such active species can be used to optimize the shelf life of food products. In addition, porous compounds have the potential to be used for sensing applications in Intelligent Packaging. In this study, encapsulation of ethanol was studied in gamma-cyclodextrin (gamma-CD) and gamma-cyclodextrin metal-organic framework (gamma-CDMOF). Benign gamma-CDMOF was synthesized using edible, bio-based compounds. Ethanol, an antifungal, antimicrobial and antiseptic compound, was encapsulated in the gamma-CD and gamma-CDMOF crystals using a vapor diffusion process. The materials were characterized using various thermal, spectroscopy and microscopy tools. It was observed that gamma-CD and gamma-CDMOF can encapsulate ~8 and 20% w/w of ethanol respectively.