*Article* **Thermal Degradation of Linalool-Chemotype** *Cinnamomum osmophloeum* **Leaf Essential Oil and Its Stabilization by Microencapsulation with** β**-Cyclodextrin**

**Hui-Ting Chang 1,\*, Chun-Ya Lin <sup>2</sup> , Li-Sheng Hsu <sup>1</sup> and Shang-Tzen Chang <sup>1</sup>**


**Abstract:** The thermal degradation of linalool-chemotype *Cinnamomum osmophloeum* leaf essential oil and the stability effect of microencapsulation of leaf essential oil with β-cyclodextrin were studied. After thermal degradation of linalool-chemotype leaf essential oil, degraded compounds including β-myrcene, *cis*-ocimene and *trans*-ocimene, were formed through the dehydroxylation of linalool; and ene cyclization also occurs to linalool and its dehydroxylated products to form the compounds such as limonene, terpinolene and α-terpinene. The optimal microencapsulation conditions of leaf essential oil microcapsules were at a leaf essential oil to the β-cyclodextrin ratio of 15:85 and with a solvent ratio (ethanol to water) of 1:5. The maximum yield of leaf essential oil microencapsulated with β-cyclodextrin was 96.5%. According to results from the accelerated dry-heat aging test, βcyclodextrin was fairly stable at 105 ◦C, and microencapsulation with β-cyclodextrin can efficiently slow down the emission of linalool-chemotype *C. osmophloeum* leaf essential oil.

**Keywords:** *Cinnamomum osmophloeum*; linalool; β-cyclodextrin; microencapsulation
