Métodos de secagem e rendimento dos extratos de folhas de Plectranthus barbatus (boldo-da-terra) e P. ornatus (boldo-miúdo)

Abstract

RESUMO: Plectranthus sp. pertence à família Lamiaceae e inclui cerca de 300 espécies. Duas delas, P. barbatus (PB) e P. ornatus (PO) destacam-se pelo interesse medicinal. As principais substâncias encontradas em Plectranthus sp. são os diterpenóides, óleos essenciais e compostos fenólicos. A melhor forma de utilizar as folhas de PB e PO é a fresco; porém, na comercialização há necessidade de recorrer a processos de secagem. Entretanto, isto pode interferir no princípio ativo, desta forma, estudos para determinar o melhor método gravimétrico são importantes. O objetivo deste estudo foi avaliar qual o melhor método de secagem, onde haja maior perda de água possível, e calcular os rendimentos dos extratos visando avaliar se o método gravimétrico interfere na quantidade de extrato produzido. Desta forma, utilizou-se quatro métodos de secagem e após evaporação do solvente, fez-se o cálculo do rendimento dos extratos secos. O percentual de água foi superior em PB e PO (média geral de 90,12±8,22%). Dentre as secagens, em estufa de ventilação forçada (EVF) foi mais eficiente em PB (88,87%) e em estufa convencional (ECO) foi melhor em PO (95,13%). O maior rendimento do extrato seco em PB foi na secagem em camada delgada (CD) (20,96%), enquanto que em PO foi ECO (41,34%). Não houve correlação entre o método de secagem e o rendimento de extrato obtido. Palavras-chave:Boldos-do-Brasil, gravimetria, pós-colheita ABSTRACT: Methods estimated drying and percentage of extracts in leaves of Plectranthus barbatus (Brazilian bold) and P. ornatus (false bold). Plectranthus sp. belongs to the family Lamiaceae and includes about 300 species. Two of them, P. barbatus (PB) and P. ornatus (PO), have medicinal interest. The main substances found in Plectranthus sp. are the diterpenoids, essential oils and phenolic compounds. The best way to use the leaves of PB and PO is cool; but for marketing there is a need of resort to drying processes. However, this may interfere on the values of active principle; thus, studies to determine the best gravimetric methods are important. The objective of this study was to evaluate the best method of drying, where there the greater loss of water possible, and calculate the percentage of the extracts to assess whether the gravimetric method interferes with the amount of extract produced. To this was done by drying four different methods ventilated dry (EVF), conventional drying (ECO), microwave (MCO) and layer thing (CD) and after evaporation of the solvent, was made the calculation the percentage of the dried extract. The water content was higher in PB and PO (overall average of 90.12±8.22%). Among the drying, EVF was more efficient for PB (88.87%) and ECO was better for PO (95.13%). The highest content of dry extract was for PB in to CD (20.96%), whereas for PO was in to ECO (41.34%). There is no relationship between the drying method and in the quantity of extract obtained.

Phytochemical analysis and antibacterial activity of extract from lantana camara l. leaves

“…[6,19] Once the ethanolic extract was obtained, it was divided in half, where one part was dried in the oven at 105ºC, for 8 hours, and the other part, dried in the rotary evaporator at reduced pressure at 42oC, for 6 hours. Then, the yield for both drying methods was calculated, based on the following mathematical expression: [20] Re = m de / m le -100%, where: Re = dry extract yield; mde = mass of the dry extract; mle = mass of the liquid extract.…”

Phytochemical Analysis and Antibacterial Activity of Extract From Lantana Camara L. Leaves

“…Once the ethanolic extract was obtained, it was divided in half, where one part was dried in the oven at 105ºC, for 8 hours, and the other part, dried in the rotary evaporator at reduced pressure at 42oC, for 6 hours. Then, the yield for both drying methods was calculated, based on the following mathematical expression [20]: Re = m de / m le -100%, where: Re = dry extract yield; mde = mass of the dry extract; mle = mass of the liquid extract.…”

Optimization of the Production Process of Bishop’s Crown Pepper (Capsicum baccatum var.) Hydroalcoholic Extract

“…The percent yield (Y%) was calculated according to Rodrigues et al (2011), considering the relation between the volume of the final extract (VFE) and the volume of the initial extract (VIE) before filtration and evaporation of the solvent. The following equation was used:…”