This paper studies the effect of different ultrasonic parameters on the yield of extraction and antioxidant activity of selected phenolic compounds from Sorbus intermedia berries. The sonication was carried out 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, 30, and 45 min. The results showed that the duty cycle significantly affected the antioxidant activity of the extracts and the yield of chlorogenic acid, rutin, and total flavonoids. Compared to the continuous mode, the pulse ultrasound increased the extraction yield of rutin by 5–27%, chlorogenic acid by 12–29%, and total flavonoids by 8–42%. The effect of the duty cycle on the extraction yield was dependent on the intensity and duration of the ultrasound treatment. The mechanism of the influence of the pulsed ultrasound field on the extraction process has been elucidated. This research clearly demonstrated the superiority of pulsed ultrasound-assisted extraction for production of antioxidants from Sorbus intermedia berries.
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.
Extending the shelf life of fruit and vegetable juices plays a key role in improving food security. Ultrasonic technology can be an effective method in the process of replacing traditional heat treatment. It offers a number of benefits, such as better product quality expressed as a higher content of bioactive substances and the preservation of the natural sensory characteristics of the juice: consistency, colour, taste and smell. This paper discusses the methods of ultrasound generation, the equipment used and advances in the construction of ultrasound devices. The influence of ultrasounds on the physical and chemical properties of juices was also analysed, with particular emphasis on bioactive substances and the effectiveness of ultrasonic treatment in the inactivation of microorganisms and enzymes. Prospects and trends in the development of ultrasonic techniques that can effectively increase the efficiency of the ultrasonic juice preservation process are also described. Sonication used alone or with other processing techniques makes it possible to achieve a positive effect on the quality of consumed fruit and vegetable juices.
The purpose of this study was to determine the impact of the pomace drying methods (freeze-drying and convection-drying) and their percentage (0–10%) on selected physicochemical properties of gluten-free bread. The contents of nutrients (protein, fiber, fat, ash, and carbohydrates), bioactive compounds, antioxidant properties, acidity, baking efficiency, and moisture of the obtained products were determined. Fortifying the bread with raspberry pomace resulted in a change in fiber content from 18.13% d. b. (control sample) up to 19.97% d. b. (10% of freeze-dried pomace), and a change in the fat and ash content in the bread from 5.74% and 2.83% d. b. (control sample) to 7.18% and 3.12% d. b. (10% of freeze-dried pomace). The content of carbohydrates decreased after adding raspberry pomace to the bread, from 65.71% d. b. (control sample) to 63.68% d. b. (5% of freeze-dried pomace). The research carried out also showed that the introduction of 10% freeze-dried raspberry pomace increased the total polyphenol content by 81.75% and the antioxidant properties defined by the ABTS method by 159.54% and by the DPPH method by 96.43% compared to the control bread. The introduction of pomace resulted in a significant reduction in the total baking loss, from 15.1% to 10.62%, and an increase in the total titratable acidity of the crumb, from 2.13 mL NaOH/10 g d. b to 7.78 mL NaOH/10 g d. b. Principal component analysis highlighted a marked effect of the drying method and content of raspberry pomace on the quality values of gluten-free bread. This research demonstrated that raspberry pomace can be a valuable source of fiber and bioactive substances in gluten-free bread.
The laser micro-machining was carried out on a station equipped with a TruMicro 5325c laser emitting ultraviolet radiation (343 nm wavelength) in picosecond pulses. On the surface of the Ti6Al7Nb alloy, dimple texturing with a constant diameter of ~200 μm, different depths (from ~5 to ~78 μm) and density (from 10% to 50%) were produced. The value of surface free energy was determined with the Owens–Wendt method using two measuring liquids: distilled water and diodomethane. The Staphylococcus epidermidis strain was used to test the adhesion of bacteria. It was found that the surface free energy value is influenced by both of the texture parameters (density, depth). The density also affects the potential for biofilm formation. Based on the analysis, it was shown that with an increase in surface free energy, the number of adhering microorganisms increases exponentially. Moreover, the study shows that there is a correlation between the number of adhering microorganisms and surface free energy.