Analysis of monoterpenoids in inclusion complexes with <i>β</i>-cyclodextrin and study on ratio effect in these microcapsules.

  • M. D. López Instituto Murciano de Investigación Agrario y Alimentario (IMIDA) C/ Mayor s/n, La Alberca, 30150, Murcia, Spain. Email address: mdolores.lopez29@carm.es
  • M. J. Pascual-Villalobos Instituto Murciano de Investigación Agrario y Alimentario (IMIDA) C/ Mayor s/n, La Alberca, 30150, Murcia, Spain

Abstract

In recent studies, the insecticide activity against some stored products pests of monoterpenoids, such as linalool, S-carvone, camphor, geraniol, γ-terpinene and fenchone, and phenylpropanoids, like E-anethole and estragole, has been proved. Currently, applications of these volatile compounds are complicated due to their chemical and physical properties. This is one of the major problems for their use as insecticides; therefore, microencapsulation could be the solution to problems of stability, evaporation and release. Microencapsulation of these chemicals was carried out with β-cyclodextrin using a chemical precipitation method at four different ratios (β-cyclodextrin: monoterpenoids), 1.33:1, 3.33:1, 4.66:1 and 6.66:1 (w/w) in order to determine the ratio effect. This study establishes that encapsulation at the ratio of 3.33:1 to linalool and γ-terpinene was higher, whereas S-carvone, camphor, E-anethole, geraniol, estragole and fenchone showed the greatest encapsulation when the ratio was 6.66:1. Furthermore, the efficiency of encapsulation was estimated by measuring the content of the compounds in the powder by gas chromatography. The maximum inclusion efficiency of β-cyclodextrin was reached by camphor (52%) followed by geraniol (34%) using 10 g of β-cyclodextrin and linalool (31%) using 5 g of this matrix. The present study indicates that natural products such as monoterpenoids or phenylpropanoids could be microencapsulated in an efficient way using an appropriate amount of β-cyclodextrin.

Keywords: Microencapsulation, β-cyclodextrin, Camphor, Geraniol and Linalool
Veröffentlicht
2010-09-02