A review of the production of slow-release flavor by formation inclusion complex with cyclodextrins and their derivatives

Flavors have been widely used in many products. They are volatile compounds and do not often last long in air especially at high temperature. The techniques for slow flavor release and long-lasting scents, for the stability of sensory perception, are much desired. The inclusion complex method encompasses the idea of molecular recognition and interactions through noncovalent bonding. It can provide protection and prevent the loss of volatile aroma materials, and improve shelf-life and enhance the stability of the entrapped ingredients of flavors. In this article, the production of control-release flavor by inclusion complex method was reviewed in considerable detail. The host materials, the method of production flavor inclusion complex, and the methods of characterization of flavor inclusion complex were depicted. The complexation thermodynamics and calculations were also discussed. Cyclodextrins and their derivatives as the host materials were discussed in this paper. Methods of production flavor inclusion complex include solution method (water or water as the main component of the solution, cosolublizer), suspension method, gas/liquid interface method, and solid phase method (co-grinding method, heating in a closed container method, shaking method at room temperature). The methods of characterization of solid inclusion complex mainly include x-ray diffraction technique, Infrared and Raman spectra, solid nuclear magnetic resonance spectroscopy, thermal analysis, mass spectrometry analysis, scanning and transmission electron microscopy. Structures, energies, and some properties of molecules can be studied by computational chemistry. The application of computational chemistry to the study of flavor compound inclusion complexes were discussed. The review indicates that inclusion complex method is an efficient way for encapsulation of flavor compounds. By this method slow flavor release and long-lasting scents can be obtained.