Acaricide activity of Piper macedoi Yunck essential oil against Rhipicephalus sanguineus

This study evaluated the acaricide efficacy of Piper macedoi essential oil on larvae of ticks of the species Rhipicephalus sanguineus. The essential oil was extracted by hydrodistillation in a Clevenger-type apparatus. The test consisted of six treatments: from the group I to IV, samples corresponded to different concentrations of essential oil (500 μg.mL-1; 250 μg.mL-1; 100 μg.mL-1 and 50 μg.mL-1) diluted in Tween 80 at 2%. Groups V and VI corresponded to the negative controls (with distilled water and Tween 80 to 2%) and the positive control (with acaricide Amitraz at 12.5%), respectively. The essential oil was rich in apiole (39.81%) and dillapiole (26.47%). The essential oil of P. macedoi presented an activity against the larvae of R. sanguineus, with a better efficiency observed for concentrating 500 μg.mL-1, mortality of 80.67%, indicating a dose-dependent response.

Chemical composition and anticancer effects of Hyptis Suaveolens L. Poit (lamiaceae) volatile oil

The leaf of Hyptis suaveolens have found application in ethnomedicine in the treatment of various ailments including those that are related to tumor and cancer. This study was therefore undertaken to evaluate the cytotoxic effects of its volatile oil. Volatile oil distilled from freshly collected leaves using a Clavenger-type apparatus was screened using tadpoles of Raniceps ranninus (10-40 µg/mL) and brine shrimp of Artemia salina (10-1000 µg/mL) with bench-top assay procedures for cytotoxicity while growth inhibitory activity was assessed using radicles of Sorghum bicolor seeds (1-30 mg/mL). The essential oils were further tested on breast cancer (AU 565) and cervical cancer (HeLa) at 50 µg /mL using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay and afterwards subjected to Gas Chromatography Mass Spectrometric (GCMS) analysis for its constituents. An LC50 of 188.67 and 8 µg/mL were obtained in the brine shrimp mortality and tadpole lethality assays respectively. The oil showed inhibitions of 86.74 and 21.8 % against AU 565 and HeLa cells respectively. GCMS analysis revealed the major constituents as sabinene (10.64 %) and (-)-4-terpineol (7.27 %). These results support its use in treating tumor-related ailments and should be considered for further studies.

Discrete-Impulse Energy Supply in Milk and Dairy Product Processing

The efficient use of supplied energy is the basis of the discrete-impulse energy supply (DIES) concept. In order to explore the possibility of using DIES to intensify the hydromechanical processes, the emulsification of milk fat (homogenization of milk, preparation of spreads) and, in particular, the processing of cream cheese masses, were studied. Whole non-homogenized milk, fat emulsions, and cream cheese mass were the object of investigation. To evaluate the efficiency of milk homogenization, the homogenization coefficient change was studied, which was determined by using the centrifugation method, as it is the most affordable and accurate one. To provide the proper dispersion of the milk emulsion, six treatment cycles must be carried out under the developed cavitation mode in a static-type apparatus, here resulting in a light grain-like consistency, and exhibiting the smell of pasteurized milk. The emulsions were evaluated according to the degree of destabilization, resistance and dispersion of the fat phase. On the basis of the obtained data with respect to the regularities of fat dispersion forming in the rotor-type apparatus, the proper parameters required to obtain technologically stable fat emulsion spreads, possessing a dispersion and stability similar to those of plain milk creams, were determined. It was determined that under the DIES, an active dynamic effect on the milk globules takes place. The rheological characteristics of cheese masses were evaluated on the basis of the effective change in viscosity. The effect of the mechanical treatment on the structure of the cheese masses was determined.

Chemical Composition and Antimicrobial Activity Against Food-Borne Pathogens of Calocedrus formosana Heartwood Essential Oil

This study investigated the chemical composition, and antimicrobial activity against food-borne pathogens of the essential oil isolated from the heartwood of Calocedrus formosana from Taiwan. The oil, isolated by hydrodistillation in a Clevenger-type apparatus, was characterized using GC–FID and GC–MS. The major constituents were τ-muurolol (16.1%), α-cadinol (11.1%), α-terpineol (10.6%), thymol (8.5%), and β-thujaplicin (4.5%). The oil demonstrated strong activity against food-borne bacterial and fungal pathogens, and, to determine the source compounds responsible for this activity , the main components were individually evaluated. The most active source compounds were determined to be τ-muurolol, α-cadinol, thymol, and β-thujaplicin.

Technical hemp harvesting cutting machine parameters and operation modes calculation

In the article, a promising scheme of a rotary type apparatus for a non-support cut of technical hemp is proposed. The main design parameters of working bodies are defined (diameter of the cutting disc, location of the cutting segments, width of the device). The operating modes of the cutting device are calculated (cutting speed, rotational speed and angular speed of the blade, torque, power applied to the drive). The research results will be used to create working bodies for harvesting technical hemp.