Dušan Adamović

Variability of content and composition of essential oil in different genotypes of peppermint

Abstract The content and composition of essential oil of ten peppermint genotypes were analyzed over three years. The parameters varied both in relation to year of investigation and the genotypes examined. Genotypes showed a specific response to environmental conditions.

Optimization of microwave‐assisted extraction (MAE) of coriander phenolic antioxidants ‐ Response surface methodology approach

BACKGROUND Microwave-assisted extraction (MAE) of polyphenols from coriander seeds was optimized by simultaneous maximization of total phenolic (TP) and total flavonoid (TF) yields, as well as maximized antioxidant activity determined by 1,1-diphenyl-2-picrylhydrazyl and reducing power assays. Box-Behnken experimental design with response surface methodology (RSM) was used for optimization of MAE. Extraction time (X1 , 15-35 min), ethanol concentration (X2 , 50-90% w/w) and irradiation power (X3 , 400-800 W) were investigated as independent variables. Experimentally obtained values of investigated responses were fitted to a second-order polynomial model, and multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions. RESULTS The optimal MAE conditions for simultaneous maximization of polyphenol yield and increased antioxidant activity were an extraction time of 19 min, an ethanol concentration of 63% and an irradiation power of 570 W, while predicted values of TP, TF, IC50 and EC50 at optimal MAE conditions were 311.23 mg gallic acid equivalent per 100 g dry weight (DW), 213.66 mg catechin equivalent per 100 g DW, 0.0315 mg mL(-1) and 0.1311 mg mL(-1) respectively. CONCLUSION RSM was successfully used for multi-response optimization of coriander seed polyphenols. Comparison of optimized MAE with conventional extraction techniques confirmed that MAE provides significantly higher polyphenol yields and extracts with increased antioxidant activity.

Essential Oil of Chamomile Ligulate and Tubular Flowers

Abstract The essential oils of tubular flowers and ligulate flowers of two chamomile genotypes diploid (2n = 18) and tetraploid (2n = 36) were examined by GC and GC/MS. The tubular flower oils of the diploid and tetraploid genotypes were found to contain α-bisabolol oxide B (17.8% and 5.9%), α-bisabolol (34.2% and 9–6%) and α-bisabolol oxide A (24.4% and 54.3%) as major components. The ligulate flower oils of the diploid and tetraploid genotypes were found to contain α-bisabolol oxide B (13.2% and 5.6%), α-bisabolol (21.3% and 9.4%) and α-bisabolol oxide A (18.3% and 45.6%). In addition, the tubular flower oil contained (E)-anediole (4.5%) while it was not detected in the ligulate flower oil. In contrast, the ligulate flower oil contained menthone (4.4%), yet it was not detected in the tubular flower oil.

Variability of Content and Composition of Essential Oil of Different Mentha arvensis L. var. piperascens Cultivars

ABSTRACT The essential oil content and composition of seven M. arvensis var. piperascens cultivars were investigated over three years. The parameters varied both in relation to environmental factors, harvest time and genotype examined. The cultivars showed specific responses to environmental conditions. Four cultivars were selected for further work because of their similarity to commercial cornmint.

The Influence of Sowing and Harvest Time on the Essential Oils of Chamomilla recutita (L.) Rausch.

ABSTRACT The influence of sowing (autumn and spring) and harvest on the content and composition of the essential oil of seventeen chamomile cultivars was investigated. For most chamomile populations, the essential oil content was significantly higher if it was spring sown rather than autumn sown. The oil composition was also found to vary, depending upon whether the cultivar was spring or autumn sown or when it was harvested.

Composition of Essential Oil Obtained From Tubular, Head and Ligulate Flowers of Calendula officinalis L. by Steam Distillation of Plant Material and CO2 Extracts

Abstract Essential oil content of tubular, head and ligulate flowers of Calendula officinalis L. were determined using official steam distillation procedure. It was found that the ligulate flower sample had the highest oil content (0.16%). Applying SFE by means of CO2 (200 bar, 40°C, 3 h extraction time), the highest extraction yield was found in tubular and ligulate flower samples (3.67% and 3.64%). Head flower had a lower extraction yield (2.60%) as the result of relatively small content of fatty oil, waxes and resins present in plant material. Steam distillation procedure was applied to obtain essential oils from the CO2 extracts devoid from cuticular waxes and resins. The compositions of oils were determined by GC and GC/MS. The main compounds of all investigated oils were α-cadinol (11.7–29.1%), δ-cadinene (3.2–20.3%), γ-cadinene (1.5–11.4%) and cadina-3,9-diene (0.4–11.2%). The oil samples obtained from the CO2 extracts were found to be more complex containing α-gurjunene, β-caryophyllene, β-gurjunene, cis-muurola-4(14)-5-diene and α-humulene.

Optimization of Satureja montana Extraction Process Considering Phenolic Antioxidants and Antioxidant Activity

The objective of this study was to employ response surface methodology to assess the effect of different extraction parameters on Satureja montana extraction process, content of total phenols and total flavonoids, as well as antioxidant activity of extracts. Optimal values of temperature and ethanol concentration for preparation of extract with highest content of total phenols were calculated as 74.1°C and 38.6%. Considering total flavonoids, the temperature of 71.0°C and 33.3% ethanol was determined as optimal. For the preparation of the extract with highest antioxidant activity (IC50 of 12.33 μg/mL), the extraction temperature of 74.9°C and 34.6% ethanol as extraction solvent should be applied.