Technical and economic evaluation of cultivation and obtaining of Varronia curassavica Jacq. essential oil

Varronia curassavica Jacq. is a native medicinal plant from Brazil, its anti-inflammatory, analgesic and healing properties are mainly due to the presence of alpha-humulene and beta-cariophyllene on the essential oil extracted from the leaves. The study aimed to evaluate parameters related to the production, harvest and extraction and their effects on the quality/quantity of the V. curassavica essential oil under field conditions. For the drying experiment it was used natural drying in greenhouse and an artificial one with forced ventilation using the temperature of 40 degrees C until constant weight with six replications per treatment. For the harvest daytime experiment, five harvest different times were evaluated (6 a.m., 9 a.m., 12 p.m., 3 p.m., 6 p.m.) with five replications per treatment. In both experiments it was used the completely randomized design. The effect of two natural elicitors on the sesquiterpene content of V. curassavica was also evaluated, where field grown plants received the application of acibenzolar-Smethyl (500 mg/L), 1,6 beta-D-glucan obtained from Lasiodiplodia theobromae (50 mg/L) and distilled water as a control, where gas exchange rate, terpene enzymes such as phenylalanine ammonia-lyase, superoxide dismutase, guaiacol peroxidase and catalase activity and essential oil content in leaves were measured. The exhaustion time for the extraction of the V. curassavica essential oil by hydrodistillation was determined for whole and ground leaves. To evaluate and compare the extraction techniques performance, it was used a conventional and a green technology, it was evaluated the essential oil yield and alpha-humulene content in the volatile oil. Finally, a study of economic viability of the implantation of an agroindustry to obtain V. curassavica essential oil was performed using Expanded Multi-index Methodology (EMIM). The essential oil yielding was determined through hydrodistillation, using a Clevenger device, and the essential oil quality was measure by Gas Chromatography. There was not statistical difference between the drying methods tested regarding the essential oil production but the highest values of alpha-humulene and beta-caryophyllene were obtained when artificial drying at 40 degrees C was adopted. It is possible to indicate a harvesting daytime around 11-12 a.m., resulting not only in higher yield of essential oil but also a higher content of the desired anti-inflammatory compounds. The acibenzolar-S-methyl reduced significantly the net carbon assimilation rate and the intercellular CO2 concentration, whilel,6 beta-D-glucan reduced significantly only the intercellular CO2 concentration. The essential oil analysis reveals that elicitation was not efficient to increase the yield of V. curassavica essential oil or to change relative rate among the oil chemical constituents, especially alpha-humulene and beta-caryophyllene. The determined exhaustion time was 1.5 h for both treatments, and the conventional extraction technology (steam distillation) is the best option for extraction of the essential oil. At last, according to the economic study, it is recommended the implementation of the investment project.