**4. Conclusions**

The thermal degradation of linalool-chemotype *C. osmophloeum* leaf oil is investigated by GC–MS. After the heat treatment, compounds β-myrcene, cis-ocimene and trans-ocimene form through the dehydroxylation of linalool and compounds limonene, terpinolene and α-terpinene by a further ene cyclization. The significantly high microcapsule yield of 96.5% is obtained from the optimal reaction conditions with the leaf essential oil to the β-cyclodextrin ratio of 15:85 and ethanol to water ratio of 1:5. Based on the accelerated dry-heat aging assay, β-cyclodextrin is stable under the environment at 105 ◦C, and microencapsulation with β-cyclodextrin effectively slows down the release/emission of leaf essential oil.

**Author Contributions:** Conceptualization, S.-T.C. and H.-T.C.; methodology, C.-Y.L., L.-S.H. and H.-T.C.; formal analysis and Investigation, C.-Y.L., L.-S.H. and H.-T.C.; writing and Editing, S.-T.C. and H.-T.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Forestry Bureau, Council of Agriculture, Executive Yuan, Taipei, Taiwan.

**Data Availability Statement:** The data are available are available from the corresponding author on reasonable request.

**Acknowledgments:** The authors would like to thank the Taiwan Forestry Bureau for the financial support and the Taiwan Forestry Research Institute for the collection of plant material.

**Conflicts of Interest:** The authors declare no conflict of interest.

**Sample Availability:** Samples are available the corresponding author.
