Effect of different drying treatments on essential oil yield, composition and color characteristics of Kelussia odoratissima Mozaff

Journal of Essential Oil Research, 27:3, 204-211

Farnam Mirhosseinia, Mehdi Rahimmalekb, Abdollah Ghasemi Pirbaloutiac & Marzyieh Taghipoora

Abstract

Kelussia odoratissima is known as an endemic and valuable spice plant. The effect of six different drying treatments (sun, shade, oven 45°C, oven 65°C, microwave and freeze drying) was studied on the color, essential oil content and chemical composition of K. odoratissima leaves. The essential oils were isolated from fresh and dried samples by a hydrodistillation method and analyzed using gas chromatography–mass spectrometry (GC MS). The highest essential oil yield was obtained by shade drying (1.50%) followed by microwave (1.46%) and oven 65°C (1.43%)-drying methods. The major compounds of K. odoratissima oils were (Z)-ligustilide, (E)-ligustilide and cis-3-butylidene phthalide. Drying treatments significantly increased (Z)-ligustilide compared with the fresh one. In this study, (Z)-ligustilide ranged from 48.67% in sun-dried samples to 68.3% in 45°C oven-dried ones. For color analysis, shade drying possessed the highest a*/b* value, followed by microwave and oven 45°C. Results showed that shade drying at ambient temperature significantly increased the essential oil yield and (Z)-ligustilide with acceptable color quality. Finally, shade and oven drying (<50°C) methods were introduced to produce appreciable essential oil yield, composition and color quality.