The effects of drying on the chemical components of essential oils of Calendula officinalis L.

Calendula officinalis is a medicinal plant whose essential oils are used for various purposes. The oils were extracted by hydrodistillation from fresh leaves, dry leaves and fresh flowers of the herb yielding0.06, 0.03 and 0.09%, respectively. The analysis of the oils by GC-MS revealed a total of 30, 21 and 24 compounds from the fresh leaves, dry leaves and the flowers in the same order. Sesquiterpenoidsdominated the fresh leaves (59.5%) and flowers (26%), while the monoterpenes dominated the oil in the dry leaves (70.3%). T-muurolol (40.9%) predominated in the fresh leaf oil; a-thujene (19.2%) and dcadinene (11.8%) were also present in high quantities. Whereas, 1,8-cineole (29.4%), g-terpenene (11.6%), d-cadinene (9.0%), b-pinene (6.9%) and a-thujene (6.3%) were the major components in the dry leaf oil. In the fresh flower oil, a-thujene (15.9%), d-cadinene (13.1%) and d-cadinene (10.9%) were the major components. The significance of the effect of drying on essential oil composition of this plant is discussed

Influência do processo de secagem sobre os principais componentes químicos do óleo essencial de tomilho

Objetivou-se, com este trabalho, avaliar o efeito da temperatura do ar de secagem sobre a qualidade do óleo essencial de folhas de tomilho. Foram empregadas diferentes temperaturas de secagem (30, 40, 50, 60, 70 ºC), em um secador com resistências elétricas. Os componentes químicos do óleo essencial, depois de realizada a secagem, foram comparados com os valores obtidos na planta in natura (testemunha). Para a extração do óleo essencial, foi empregado o método de extração com CO2 supercrítico. A identificação dos componentes químicos do óleo essencial foi realizada por cromatografia gasosa, acoplada ao espectrofotômetro de massas (CG-EM) e, para a quantificação desses componentes, empregou-se o cromatógrafo a gás, acoplado ao detector por ionização de chamas (CG-DIC). Em função dos resultados obtidos, recomenda-se ar, à temperatura de 60 ºC, para a secagem das folhas de tomilho

Drying Technologies: Vehicle to High-Quality Herbs

Herbs are usually marketed as dry due to a consumer demand beyond their seasonality; dehydration leads to a stable, easily moveable product that is available throughout the year. The process of drying, though, leads to modifications in the appearance, composition and quality of the raw material. The extent of these alterations depends on the applied drying methodology and its parameters, rendering the optimization of this process imperative. Numerous studies examining the effect of drying on the main characteristics of herbs have been published in recent years, and this review aims at organizing the available information of the studied herbs, drying methods and measured parameters in a comprehensive manner. Primarily, since aroma is the main characteristic of herbs and the principal aim for the end product is to retain the raw material’s character, this review will focus on the most widely studied effect of drying, which is the essential oil yield and composition. Secondly, results from various studies on the influence of drying on biochemical compounds, organoleptic properties of dried herbs are also presented. The most common approach to the study of drying kinetics is also presented. Finally, novel technologies targeting to minimize the magnitude of changes from the raw material are described