Effect of drying and distillation techniques on the oil ingredients of mint (Mentha sp.)

Abstract

Background and Objective: The essential oil (EO) of mint used in food and pharmaceutical industries. Drying and distillation techniques play an important role in the EO production from mint. The aim of this investigation was to evaluate the EO composition of mint plants under various drying and distillation techniques. Materials and Methods: The fresh herb of Mentha longifolia (L.) Huds. ssp. schimperi Briq and Mentha longifolia (L.) Huds. ssp. Longifolia were subjected to different drying techniques such as shad, sun and oven drying (40°C) compared with fresh herb. On the other hand, dried herb of Mentha piperita L. and Mentha citrate (Ehrh.) was subjected to various distillation techniques (hydro and stem). The EO content and its constituents were evaluated under drying and distillation techniques. The averages data were statistically analyzed using 2-way analysis of variance (ANOVA-2) with 0.05 level of significance. Results: The greatest amounts of EO and its major constituents were produced from fresh plants, followed by the plants treated with shade, sun and oven techniques respectively. Higher values were detected in EO and major components under hydro distillation than steam distillation. Conclusion: Separation of EO from the fresh mint is the best way to obtain the high quantity and quality of peppermint EO, however, in the case of peppermint EO separation in remote places, the drying technique can be used in the shade to reduce the size and avoid disease. Isolation of EO with hydro distillation technique is requiring for increasing the quantity and quality of mint EO.