Mariane Borges Rodrigues de Ávila

The aim of this study was to evaluate the influence of pretreatment (ultrasound + etanol), associated with different drying air temperatures, on the yield and quality of the essential oil of ripe fruits of Schinus terebinthifolius Raddi and to adjust previously described mathematical models in the specialized literature in order to obtain graphical representation of the drying kinetics. The experiments were conducted according to a Central Composite Design considering two factors with the following ranges: pre-treatment duration (ultrasound+ethanol) from 0 to 12 minutes and drying air temperature from 40 to 80 ºC. Four mathematical models, namely: Lewis, Page, Midilli, and Henderson & Pabis, were fitted to the experimental data. The essential oil was extracted by hydrodistillation and its constituents were identified by gas chromatography coupled with mass spectrometry (GC–MS). The Midilli model best represented the drying kinetics of ripe fruits of S. terebinthifolius pretreated with ultrasound + ethanol. The drying time of S. terebinthifolius fruits was influenced both by the pretreatment duration (with linear effect) and by the drying air temperature (linear and quadratic effects). None of the evaluated factors showed significance on the essential oil yield. It was not possible to adjust a model that simultaneously optimized the drying time and the yield of the essential oil of ripe and dried fruits of S. terebinthifolius, previously treated with ultrasound + ethanol.

Drying is an important step, as it extends plant durability and delays the development of undesirable microorganisms. However, depending on the drying method, conditions involved and plant species, changes can occur in the plants, which can improve or reduce their medicinal properties. Ultrasonic pretreatment has the advantage of facilitating water migration into the cells, improving the drying rate. In this context, the objective of this study was to evaluate the influence of different drying temperatures associated with ultrasonic pretreatment, on the chemical composition of the essential oil from Cyperus rotundus L. tubers. The assays were conducted according to a Central Composite Rotational Design (CCRD), considering two factors with the following ranges: duration of the ultrasonic bath from 0 to 40 minutes, drying air temperature from 40 to 70 ºC. The essential oil was extracted by hydrodistillation and its constituents were identified by gas chromatography coupled to mass spectrometry (GC–MS). Twenty-four compounds were identified in C. rotundus essential oil, corresponding to more than 70% of the total peak areas resulting from the chromatographic reading. In the twelve drying treatments evaluated, the compounds 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde, caryophyllene oxide and α-cyperone were found at higher concentrations (between 17.85-25.38%; 17.27-25.26%; 4.95-11.34%, respectively) in eleven; in treatment 11, the major compounds were caryophyllene oxide (23.40%), 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde (21.5%) and humulene (8.41%). At high temperatures and long ultrasonic times, a lower quality of C. rotundus essential oil was observed. The best results were obtained at intermediate ultrasonic bath temperatures and times, where there was an improvement in quality compared to fresh tubers (control).

The aim of this study was to evaluate the influence of different drying temperatures associated with ultrasound+ethanol pre-treatment on the chemical composition of the essential oil from ripe fruits of S. terebinthifolius. The experiments were conducted using a Central Composite Design, considering two factors within the following ranges: duration of ultrasound+ethanol pre-treatment from 0 to 12 minutes, drying air temperature from 40 to 80 °C. The essential oil was extracted by hydrodistillation, and its constituents were identified by gas chromatography-mass spectrometry (GC-MS). In the essential oil of S. terebinthifolius, five compounds were identified, accounting for over 80% of the total peak areas from the chromatographic analysis. Applying different pre-treatment times combining ultrasound and ethanol, along with different drying temperatures, resulted in qualitative changes in the chemical composition of the essential oil of S. terebinthifolius. The most satisfactory results were achieved at drying air temperatures of 50 °C and 70 °C, with shorter ultrasound+ethanol pre-treatment times. Additionally, it was observed that longer ultrasound+ethanol pre-treatment times (12 minutes) led to a reduction in the quality of the essential oil of S. terebinthifolius.

Despite the broad therapeutic action of plant species with bioactive compounds and drying being the most recommended operation for maintaining the quality of various plant materials, the fact that these materials differ in terms of moisture content, chemical composition, and morphology makes the optimization of drying methods and parameters for each species essential tools for obtaining dried plant biomass of high commercial value. The use of ethanol as a pre-treatment for drying, through immersion, allows for the modification of the product's natural structure and improves moisture transfer, consequently increasing the drying rate (KOMPANY et al., 1990). Ultrasonic waves can increase the availability of energy and accelerate mass transfer processes in the product, preserving its main qualitative attributes without significantly raising the drying air temperature (O’DONNEL et al., 2010). Therefore, this review aimed to elucidate the use of ultrasound and/or ethanol pre-treatment in the drying of various medicinal plant species, exploring their mechanisms of action and addressing their main effects on the desorption process and the chemical composition of these materials.

This study investigated the effect of intermittent drying on the specific energy consumption, plant extract yield, content of phenolic compounds, flavonoids, and antioxidant activity of L. origanoides leaves. Drying tests were carried out at the Postharvest Laboratory of Medicinal, Aromatic and Spice Plants of the Agricultural Engineering Department of the Federal University of Viçosa, Viçosa, MG, Brazil (20 ° 46 '13, 5 ”S; 42 ° 52 ' 23.3 ”W, and 645 m altitude) in June 2019. The experiment was conducted using a 3 × 4 factorial scheme matching three drying temperatures (50, 60 and 70 °C), with two drying methods: drying continuous and intermittent drying (with three intermittent ratios between drying and resting in minutes: 10/20, 15/15 and 20/10). The design used was completely randomized and with three replications. Drying with a 10/20 intermittency ratio reduced the specific energy consumption during the drying of L. origanoides leaves at 50 and 70 °C. The application of the 10/20 intermittency ratio maximized the yield of plant extract during the drying of the leaves of L. origanoides at 60 and 70 °C. Drying with a 10/20 intermittency ratio maximized the content of total phenolic compounds and total flavonoids at all evaluated drying air temperatures. Intermittent drying did not significantly affect the antioxidant activity of the plant extract of L. origanoides leaves.

Piptadenia gonoacantha is a tree species with several biological properties. The objective of this study was to evaluate the action of two pharmaceutical formulations, ointment and balm, containing Piptadenia gonoacantha extract, on the healing of wounds made in 45-day-old male mice. The animals were randomly grouped and 3 treatments with 6 repetitions were performed: an ointment containing the extract; balm containing the extract and silver sulfadiazine was used as the positive control. Tissue samples were collected on the 4th and 8th days. Treatment began immediately after the injury, and the treatments were applied once a day throughout the experiment. Treatment with the balm formulations on day 4 and the ointment on day 8 had better wound area regression rates compared to the control group, 45.4% and 81.6%, respectively. The balm and ointment treatments provided a reduction in vascularity indicating a reduction in the inflammatory process, initiating the proliferative phase in the scar tissue. These data were supported by the analysis of collagen synthesis. The results pointed out the efficacy of balm and ointment formulations concerning sulfadiazine. Therefore, the balm formulation is indicated for the beginning of the treatment, while the ointment formulation is indicated for continuation and end of treatment.

O reconhecimento das propriedades terapêuticas é tão antigo quanto a ocorrência dos humanos na Terra. Independentemente da finalidade do uso de plantas medicinais, não há dúvida de que tem havido um aumento na demanda por métodos naturais, representando um grande desafio para produtores e pesquisadores, no que diz respeito à padronização e controle de qualidade da matéria-prima, para garantir a qualidade das espécies oferecidas aos consumidores e à indústria farmacêutica. Apesar do aumento do consumo e consequente expansão do mercado de plantas medicinais, poucos são os estudos específicos envolvendo a utilização de técnicas de embalagem e armazenamento para esse tipo de produto. Diante do exposto, este estudo levantou conceitos envolvendo embalagens, bem como características de alguns polímeros comumente utilizados no armazenamento de produtos de origem vegetal, técnicas e equipamentos utilizados na embalagem de produtos alimentícios e trabalhos envolvendo o uso de atmosfera modificada na área de armazenamento de plantas medicinais.

This study investigated the effect of a drying method with intermittent ratios on the effective drying time, specific energy consumption and essential oil yield of clove basil (Ocimum gratissimum L.) leaves. The drying tests were conducted at the Postharvest Laboratory of Medicinal, Aromatic and Condiment Plants, from the Departamento de Engenharia Agrícola of the Universidade Federal de Viçosa, Viçosa, MG, Brazil (20° 46’ 13.5” S; 42° 52’ 23.3” W, and altitude of 645 m) in October and November 2017. The experiment was conducted by using a 3 × 4 factorial scheme including three drying temperatures at 50, 60 and 70 °C, with four drying processes: continuous drying and the following three intermittent drying/tempering ratios in minutes: 10/20, 15/15 and 20/10. The design was completely randomized and with three repetitions. The application of the 10/20 intermittent ratio reduced the effective drying time and the specific energy consumption. Regarding the essential oil yield, the use of the intermittence presented different results for each temperature of drying; the highest yields were observed with continuous drying at 50 °C and drying with the 20/10 intermittent ratio at 60 °C. The results indicate that intermittent drying at 50 °C is not recommended to preserve essential oil yields.