Dielectric barrier discharge (DBD) cold plasma (CP) was used for surface treatment of fennel (Foeniculum vulgare Mill.) seeds and spearmint (Mentha spicata L.) leaves, followed by hydro-distillation, to enhance essential oil (EO) yield extraction. Response Surface Methodology (RSM) was applied to optimize the EOs yields extraction. The experiments were designed using the central composite design (CCD) with two independent variables: X1: exposure times (5-15 min); and X2: applied voltage values (17-23 kV). The EOs yields were enhanced by small defects, generated on the fennel seed coat and spearmint leaf surface. The optimum yield was achieved at 10 min exposure time, and 19 kV applied voltage, by 1.83 (% v/w) and 1.81 (% v/w), consi

The genus Stachys is a member of the Lamiaceae family. These are important medicinal plants which grow all over the world and are known for their flavoring and therapeutic effects and Stachys lavandulifolia is an endemic species of Iran. To acquire high‐quality essential oil (EO), drying technique was implemented which is an essential part of this process. The present study designed to evaluate the influences of different drying techniques (fresh sample, shade, sunlight, freeze‐drying, microwave, and oven‐drying (40, 60, and 80?C) on EO yield and composition of S.?lavandulifolia. The results indicated that the maximum EO yield was obtained by the shade‐drying method. The main compounds found in the fresh samples were spathulenol, m

The amount of active compounds of medicinal plants (e.g. essential oil) varies in different plant parts. Thus, it is important to harvest those parts containing the highest levels of active compounds. In the present study the effect of harvest height on quantity and quality of Hyssopus officinalis was investigated based on a randomized complete block design with three replications. Treatments included four harvest heights including 15, 25, 35, and 45 cm (in basipetal order) and the residual stalks. After measuring the essential oil, the component values analyzed by GC and GC/MS. Regarding essential oil content (% v/w), yield and dry matter of different heights, the 15 cm height had the highest amount of essential oil (1.02?0.01%) and the lo

In the present study, the effects of graphene oxide (GO) nano-particles on performance and emissions of a diesel engine fueled with Oenothera lamarckiana biodiesel was investigated. Biodiesel was used in the blend of B20. The GO nano-particles with concentrations of 30, 60, and 90 ppm were considered for each fuel blend. Experiments were performed at a constant speed of 2100 rpm at loads of 0%, 25%, 50%, 75%, and 100%. Various parameters, such as power, exhaust gas temperature (EGT), carbon monoxide (CO), carbon dioxide (CO2), unburned hydrocarbons (UHCs), and nitrogen oxides (NOx), were investigated. Results showed that by using GO, power and EGT significantly increase. Furthermore, by using GO nano-particles, significant reductions

Physicochemical characteristics of three type biodiesel feedstock and diesel engine parameters fuelled with graphene oxide (GO) nanoparticles addition in diesel/biodiesel blends have been investigated. Three types of oilseeds, namely Evening primrose (Oenothera lamarckiana), the fruit of Tree of heaven (Ailanthus altissima) and Camelina (Camelina sativa), were selected as suitable resources for Iran. The result showed that the Tree of heaven contains 38% oil which is higher than the Evening primrose (26%) and Camelina (29%). Physicochemical properties of the oils showed that the viscosity of the Camelina oilseeds was less than the Tree of heaven oilseeds and Evening primrose oilseeds. Therefore, in terms of viscosity, the Camelina oilseeds

The growing demands of consumers for edible seed oils containing high unsaturated fatty acid and antioxidant content have resulted in considerable efforts to investigate plants as possible sources of oils and nuts. In this research, the amount of fatty acid compositions, total flavonoid, phenol and antioxidant properties of Pistacia atlantica and Pistacia khinjuk were evaluated. The kernel oil content of P. atlantica and P. khinjuk were 24.33 ? 0.333% and 31.00 ? 0.577%, respectively. Palmitic acid, Stearic acid, Oleic acid, Linoleic acid, and Palmitoleic acid were the main components in the oil of the two Pistacia species. The results showed that unsaturated fatty acids accounted for approximately 77.65% and 74.87% of total fatty acids in

Biodiesel is a renewable fuel that has been widely used in recent years. There are various resources used as biodiesel feedstocks, including animal fats, waste oils, and vegetable oils. In the present study, Chrozophora tinctoria seed oil is introduced as a new biodiesel feedstock. C. tinctoria is a weed and non-edible plant. So, the primary cost of this resource is very low, and hence it can be considered as a biodiesel source. This plant can also grow in most weather conditions. In the present study, the research team tried to produce biodiesel from C. tinctoria seeds through a transesterification reaction. To intensify the transesterification reaction, an ultrasonic device was used. In order to perform the transesterification reaction, p

In this study, the effect of microwave drying method (at five power levels: 200, 400, 600, 800 and 1000 watts) on drying time, color color Subject Category: Properties

This research aimed to investigate natural (shade and sun drying) and artificial drying methods (oven, vacuum, microwave, infrared and freeze-drying) on the spearmint essential oil (EO) quality and its trichomes. Fresh plant (control), shade dried, sun dried, freeze dried, oven dried at 40, 50, and 60 ?C, vacuum dried at 40, 50, and 60 ?C, microwave dried at 100, 200, 300, 400, 500 and 600 W and infrared dried at 125,132 and 225 W spearmint samples were evaluated. The EO of samples was isolated by hydro-distillation method and their components identified by gas chromatography (GC) and gas chromatography/mass spectrometry (GC–MS). The results revealed that shade drying required the highest drying time (28 h) whereas the lowest (0.2 h) was