Physicochemical characterization of the inclusion compounds of eugenol and β-caryophyllene in β-cyclodextrin

Abstract

The present work was carried out to encapsulate the essential oil (EO) constituents (i.e., eugenol and β-caryophyllene) inside β-cyclodextrin. Encapsulates were subjected to physicochemical characterization. Absorption λmax for eugenol and β-caryophyllene were observed at 280 nm and 230 nm, respectively. Scanning electron microscopy (SEM) analysis of encapsulates revealed rough surfaces, cracks and sharp edges; the particles were in the micrometre size range and are, therefore, referred to as microparticles. Characteristic peaks of eugenol were recorded at 3516 cm–1 (OH), 2842–3000 cm–1 (C-H stretching) and 1511 cm–1, 1611 cm–1 and 1638 cm–1 (C=C aromatic ring) via Fourier transform infrared (FTIR) spectroscopy. The FTIR spectrum of β-caryophyllene showed peculiar bands at 3067–2856 cm–1 and 1671–885 cm–1. Thermogravimetric analysis (TGA) data showed complete weight loss for eugenol and β-caryophyllene in the range of 30–215 °C. In contrast, encapsulated eugenol and β-caryophyllene showed weight loss in the range of 300–580 °C.