A review on cyclodextrin encapsulation of essential oils and volatiles

Abstract

Cyclodextrins (CyDs) are cyclic carbohydrates derived from starch. The parent CyDs contain six, seven and eight glucopyranose units and are referred as a-, b-and g-CyD, respectively. The most important property of the CyDs is the ability to establish specific interactions -molecular encapsulation -with various types of molecules through the formation of noncovalently bonded entities, either in the solid phase or in aqueous solution. These nano-encapsulating agents may form inclusion complexes with essential oils and volatiles, or their components, in order to improve their characteristics, such as transformation of liquid compounds into crystalline form; masking unpleasant smells and tastes of some compounds; improving the physical and/or chemical stability; and stabilizing volatile compounds by reducing or eliminating any losses through evaporation. Complexation has been used to avoid the destruction of certain flavours by processing or, on storage, allowing the use of minor amounts of flavours. The guest molecule is released in the warm moisture of the mouth. Examples are spices, essential oils of vegetable origin and plant flavours, chamomile oil and extract, eucalyptus oil, fennel oil, lemon oil, onion and garlic oil, camphor, menthol, thymol, etc. There are several methods for the preparation of inclusion complexes; kneading, co-precipitation, freeze-drying and spray-drying the most commonly used. Evidence for a guest inclusion into the apolar CyD cavity may be proved by various analytical techniques, including NMR spectroscopy, UV-visible absorption spectroscopy, optical rotatory dispersion and circular dichroism, fluorescence, infrared/FT-IR spectroscopy, thermo-analysis, TLC, mass spectromety, and powder X-ray diffractometry.

Statistical optimization of medium components for chitinase production byPseudomonas fluorescensstrain HN1205: role of chitinase on egg hatching inhibition of root-knot nematode

“…Yeast extract source had a significant effect on chitinase production. [26,33,34] Shrimp shell waste containing chitin source was reported to be an important factor for chitinase production. [35] Gohel et al [36] has reported CaCl 2 as an influential media constituent for chitinase production by Pantoea dispersa.…”

Gelatin-Based Films and Coatings for Food Packaging Applications

“…In order to protect additives from temperature or light, encapsulation is a promising technique that can be used during film processing [58,59]. Liu et al investigated the applicability of gelatin-based films packaged with sunflower oil with different free/encapsulated tea polyphenol ratios through the synthesis of chitosan nanoparticles at 3 different encapsulation efficiencies (50%, 80% and 100%).…”

β-Cyclodextrins as Encapsulating Agents of Essential Oils

“…This way, the formation of inclusion complexes is result of an equilibrium between the free and CD molecules and the bioactive compounds-CD complex [99]. Therefore, some factors may affect inclusion complex formation, such as type of cyclodextrin, cavity size, pH and ionization state, temperature, and method of preparation [102].…”

“…These inclusion complexes are relatively more hydrophilic and larger in size than the non-associated active compound, which helps to increase the retention of the encapsulated substance. They are also very interesting because they can mask undesirable flavors and odors that the encapsulated compounds may present [21,56,72,101,102,[106][107][108][109][110].…”

“…Marques [102] notes that the goal of encapsulation using cyclodextrin is to reduce the volatility and toxicity of the encapsulated compounds, provide protection of compounds that are sensitive to factors that promote their degradation, and alter the kinetics of migration and release of the encapsulated active components into the external environment.…”