This study investigated the impact of sonication parameters on the efficiency of the extraction of bioactive substances from hawthorn berries. The ultrasonic treatment was performed in two modes: continuous and pulse. In the pulse mode, the samples were sonicated with the following processor settings: 1 s on-2 s off. The effective ultrasonic processor times were 5, 10, and 15 min, and the total extraction times were 15 min, 30 min, and 45 min. The content of total polyphenols and total anthocyanins was determined by a spectrophotometric method. We show that the operating mode of the processor affects extraction efficiency, energy consumption and unit energy inputs. Extraction supported by a pulsating ultrasonic field allowed saving from 20% to 51% of energy with a simultaneous higher efficiency of the process. In addition, we show that the unit energy consumption in the pulsed mode was about 40% to 68% lower than the energy consumption in the case of continuous operation.

This study investigated the effects of particle size and ultrasonic parameters on the yields of bioactive compounds extracted from the leaves and inflorescences of hemp. The total flavonoid and anthocyanin contents were determined using the spectrophotometric method. The response surface methodology (RMS) was employed to optimize the yield of bioactive substances. On the basis of the developed model, the highest flavonoid yield was obtained under the following extraction conditions: particle size, 0.59 mm; extraction time, 10.71 min; ultrasound intensity, 7.13 W∙cm−2; extraction yield, 9.28 mg QE∙g−1; determination coefficient, R2 = 0.97. The optimal conditions for extracting anthocyanins were as follows: particle size, 0.25 mm; extraction time, 15 min; ultrasound intensity, 8.60 W∙cm−2; extraction efficiency, 20.27 mg Cy-GE∙100 g−1; determination coefficient, R2 = 0.87. This study helped confirm the importance of pulsed ultrasound-assisted extraction in obtaining bioactive compounds from hemp.

The paper presents the comparison of quality of six different commercial apple juices produced in Poland. The apple juices came from two different Polish companies. From each manufacturer three various juices were selected: two cloudy and clarified one produced as a mixture of different apple varieties. The following properties were evaluated: density, soluble solid content, viscosity, total phenolic contents, phenolic acid, and antiradical activity. The obtained results showed that three from fourth cloudy juices (M1Sz, M1A and M2A) differed from clarified juices. The highest differences were noticed for total phenolic contents, phenolic acids, antiradical activity and viscosity. The values of these properties ranged between 60.72–103.6 mg GAE·100−1 mL−1 for phenolic contents, 78.3–90.9% for antiradical activity and 2.68–5.79 mPa·s for viscosity. The remaining cloudy juice (M2Sz) was more similar to the clarified ones. The strong correlation between total phenolic content and antiradical activity of apple juices was found. The high correlation coefficient obtained between these features indicates that both producers do not apply excessive amounts of vitamin C during the production of cloudy apple juices. There was also a strong interrelation between the density of juice and solid soluble content. However, no correlation was found between the solid soluble content and the viscosity of the tested juices.

We report the experimental results of tests aimed at assessing the effects of different settings on the mean radius of mineral fertilizer distribution using a disc fertilizer spreader. Our aim was to improve the performance of fertilizer distribution in sustainable agriculture. Three types of mineral fertilizers with different physical characteristics, commonly used in agriculture, were considered: urea, calcium ammonium nitrate and ammonium sulfate. A complete randomization method based on a four-factor experimental model was used to study the influence of the functional and operational parameters on the mean radius of fertilizer spread. Fixed model analysis of variance showed that fertilizer type, vane configuration and disc angular velocity explained 91.74% of the variance of the spread mean radius, while linear multiple regression analysis highlighted that the fertilizer dust fraction and disc angular velocity had an overall effect of 82.72%, the former showing an inverse correlation as high as 72.77%.

Introduction. Work in forestry has been and continues to be considered a very difficult and risky occupation, with constant exposure to certain factors which create risk for employees' health or even life. The objective of the study is recognition of the opinions of forestry workers concerning health risk, and to evaluate which of their selected demographic characteristics are connected with opinions concerning hazards at the workplace. Materials and method. An author-constructed survey was conducted among 135 forestry employees, containing items concerning primarily hazards occurring at workplaces in forestry. Forestry employees' opinions pertaining to occupational hazards were analyzed from the aspect of independent variables, such as workplace, period of employment, age and education. The significance of the differences in the subgroups distinguished according to the above-mentioned variables, were assessed using the chi-square test. Results. Forestry employees most often indicated risk related with cold (83.7%) and hot (77%) microclimate. A high percentage of respondents (74.1%) were aware of the presence of biological hazards and risk caused by the possibility of contact with wild animals (55.6%) at their workplace. In addition, a considerable part of workers reported that the source of risk at their workplace is noise (34.1%), especially dangerous machinery (26.7%), dust (18.5%), chemical substances (15.6%), and forced body position at work (14.1%). Conclusions. Based on the results of the study concerning work safety and occupational hygiene among forestry employees, it was found that they are aware of hazards which may occur at their workplaces. The greatest differences in the perception of hazards were observed according to the type of workplace and period of employment.