Optimization of a method for preparing solid complexes of essential clove oil with beta-cyclodextrins

Abstract

BACKGROUND Clove oil (CO) is and aromatic oily liquid used in food, cosmetic and pharmaceutical industries due to their functional properties. However its disadvantages as pungent taste, volatility, light sensitivity and poor water solubility can be solved by applying microencapsulation or complexation techniques. RESULTS Essential CO was successfully solubilized in aqueous solution by forming inclusion complexes with -cyclodextrins (beta-CDs). Moreover, phase solubility studies demonstrated that essential CO also forms insoluble complexes with beta-CDs. Based on these results, essential CO-beta-CD solid complexes were prepared by the novel approach of microwave irradiation (MWI) followed by three different drying methods: vacuum oven drying (VO), freeze drying (FD) or spray drying (SD). Quantification of the solid complexes formed pointed to the treatment not involving heat, FD, as the best drying method, followed by VO and SD, which led to significantly lower amounts of encapsulated essential CO. CONCLUSION. MWI can be used efficiently to prepare essential CO-beta-CDs complexes with good yields on an industrial scale.