Teor, rendimento e composição química do óleo essencial de plantas de manjericão submetidas ao estresse salino com NaCl

Abstract

RESUMO:O objetivo do presente trabalho foi avaliar o teor, o rendimento e a composição química do óleo essencial de manjericão (Ocimum basilicum L.) submetido ao estresse salino por NaCl. Para tanto, o experimento foi conduzido em casa de vegetação, sob delineamento inteiramente casualizado, caracterizado por 5 (cinco) tratamentos de NaCl, adicionados à água de irrigação (0,01 -controle,T1; 1,2 -T2; 2,3 -T3; 3,4 -T4 e 4,5 dS m -1 -T5, correspondendo respectivamente a 0,1; 12,0; 23,0; 34,0 e 45,0 mM ), com 4 (quatro) repetições. Aos 55 dias após o transplantio, as plantas foram colhidas, colocadas em sacos de papel e levadas a estufa de secagem com fluxo de ar forçado a 45 °C, por 10 dias até atingirem massas constantes. Após a secagem, foi realizada a pesagem da biomassa seca da parte aérea, misturada, moída em triturador elétrico de facas e posteriormente realizada a extração do óleo essencial para análise do teor, rendimento e composição química. O aumento do estresse por NaCl não alterou o teor e a composição química do óleo essencial, cujo rendimento reduziu 12,93% a cada acréscimo unitário dos níveis de salinidade. O cinamato de metila, cujo teor médio encontrado foi de 55%, e o metil chavicol, com 12%, foram os principais compostos identificados nas plantas de manjericão.Palavras-chave: salinidade, Ocimum basilicum L., metabolismo secundário ABSTRACT: Content, yield and chemical composition of essential oil of sweet basil plants subjected to NaCl saline stress. This study aimed to evaluate the content, yield and chemical composition of the essential oil of sweet basil (Ocimum basilicum L.) plants subjected to NaCl saline stress. The experiment was carried out in a greenhouse, in a completely randomized design, with 5 (five) NaCl treatments added to the irrigation water (0.01 -control, T1; 1.2 -T2; 2.3 -T3; 3.4 -T4 and 4.5 dS m -1 -T5, corresponding respectively to 0.1; 12.0; 23.0; 34.0 and 45.0 mM) and 4 (four) replicates. At 55 days after transplanting, plants were harvested, put in paper bags and taken to a forced-air oven at 45 ºC for 10 days, until reaching constant mass. After drying, the dry biomass of the aerial part was weighed, mixed, grinded in an electric blade grinder and later taken to an essential oil extraction so that its content, yield and chemical composition could be analyzed. The increase of NaCl stress did not change neither the content nor the chemical composition of the essential oil, whose yield was reduced by 12.93% for each unit increase in the salinity level. The methyl cinnamate, with an average content of 55%, and the methyl chavicol, with 12%, were the main compounds identified in the sweet basil plants.

Composition variation of the essential oil from Ocimum basilicum L. cv. Genovese Gigante in response to Glomus intraradices and mild water stress at different stages of growth

“…Furthermore, another study of various cultivars of basil (including the Genovese Gigante) asserted that, with regards to the main compounds, all the cultivars were characterized by a high relative percentage of linalool (41-76%) and relatively abundant amounts of 1,8-cineole (1-12%), τ-cadinol (2-8%), and trans-α-bergamotene (1-3%) during the flowering stage (Marotti et al, 1996) -which is in accordance with our results. In addition, the relative percentage which the samples presented (except for the WS samples) regarding eugenol (7.1-21.3%) agrees with the relative percentage obtained for this compound in EO samples of O. basilicum L. grown in Portugal (9.7-17.6%) (Roque, 1991). The chemical analysis enabled us to confirm that this cultivar is the Genovese Gigante.…”

Use of hydrogen peroxide in acclimation of basil (Ocimum basilicum L.) to salt stress

“…Bernstein et al (2010) verified an increase in essential oil content using seedlings of basil, cultivar "Perrie", under salt conditions. In contrast, Alves et al (2015) reported a decrease in oil yield in basil (unidentified cultivar), with further increases of salinity. In our work, the results clearly show that, in the 'Gennaro de Menta' cultivar, the essential oil content, yield, and productivity are increased by both salt stress and H 2 O 2 application.…”

“…It is cultivated for the in natura trade and mainly for the industrial production of essential oils widely used in the pharmaceutical industry (Lorenzi and Matos, 2008). According to Alves et al (2015), the highest concentrations of essential oil are found in leaves, floral calyces, secretory channels, and glandular hairs. In addition, the amount of oil may be affected by environmental stresses such as water deficit and salinity, but this effect depends on factors such as type, intensity, and duration of the stress (Alves et al, 2015).…”

Biomass production and essential oil content and composition in basil hydroponic systems using treated domestic effluents

“…The oil was extracted from the leaves, which were separated from the stems after drying. In a 30 g sample of ground leaf dry biomass (LDB) as previously established by Alves et al (2015), the oil was extracted with hydrodistillation using a Clevenger apparatus (Clevenger, 1928). The distillation time (2 h) was counted from the moment the first drop of essential oil was deposited in the collector.…”