The Effect Of Biofertilizers And Different Drying Method On The Quality And Quantity Of Lemon Balm (Melissa Officinalis) Essential Oil

Abstract

The aim of this study was to apply mycorrhiza and azotobacter biofertilizers to increase the yield and recognize the most proper method for drying Lemon Balm to conserve the quality and quantity of active ingredients. The transplants were treated with mycorrhiza and azotobacter before beding transferred to the main field. The drying process was carried out subjected to sun, shading, oven (35 and 55 oC), and microwave (Output power of 100, 300, 900 w), and the quality and quantity properties were measured. Variance analysis showed that Mycorrhiza and Azotobacter significantly affect the quantitative traits, including fresh weight and dry weight, plant height, leaf number per plant, 10 leaf area, and the essential oil percentage (P<0.05). Drying methods significantly affect the essential oil percentage, appearance, Geraniol, Neral, Citronella, Caryophyllene Oxide, Citronellal, Beta-Caryophyllene, Geranyl acetate, and Geraniol (P<0.01). Mycorrhiza increased the Lemon Balm’s essential oil percentage. Appearance, essential oil percentage, and the effective ingredients of the essential oil, such as Geranial (citral a), citronella, and caryophyllene oxide, and drying in the shades exhibited a better performance compared to the other drying methods (drying under the sun, in the oven, and in the microwave) (P<0.05). For Geranial, Neral and Citronella drying under the sun and in the oven proved to be the best methods, respectively. Increasing the oven temperature negatively affects the Lemon Balm’s essential oil. It could be suggested to use mycorrhiza in order to improve the Lemon Balm yield. Additionally, saving time and expenses are among the other benefits of rapid drying methods, such as a low-temperature oven and the low-output power of the microwave.