This study investigates the effects of ultrasound, in combination with chemical pretreatments, on the quality attributes (total phenolic and carotenoid content, antioxidant activity (2,2-Diphenyl-1-picrylhydrazyl assay (DPPH)), ferric-reducing ability (FRAP), CIE L* a* b* color, non-enzymatic browning, rehydration ratio, textural and morphological properties) of red pepper subjected to drying (hot air drying or freeze drying). The fractional factorial design was used to assess the impact of factors. The global Derringer desirability function was used to determine the optimal conditions for the best quality attributes of dried pepper. The drying method influenced total phenolic content, a* (redness), and initial rehydration ratio; pretreatment time significantly affected FRAP antiradical activity, a*, chroma and non-browning index, while pH-value had a significant effect on the texture of dried pepper. Non-enzymatic browning was reduced to 72.6%, while the DPPH antioxidant capacity of freeze-dried peppers was enhanced from 4.2% to 71.9%. Ultrasonic pretreatment led to changes in the pepper morphology, while potassium metabisulfite (KMS) was a more effective additive than citric acid.

The aim of this research is to study the drying kinetics of vacuum-dried and freeze-dried bee honey produced from two different varieties: Sunflower honey (Helianthus Annuus L.) and Acacia honey (Robinia pseudo acacia L.). Vacuum drying treatments were carried out with the honey samples? initial temperatures of +25?C, ?20?C, and ?40?C. Water content, total soluble solids, as well as the water activity of fresh and dried honey samples were determined. Freeze-drying of bee honey with initial sample temperature of ?40?C has resulted in shorter drying time (7-9 hours), moisture content (10%-12%), water activity (0.405-0.427 aW) and effective moisture diffusivity coefficient (8.26?10?7-9.51?10-7 m2/s). The high-performance liquid chromatography method was used when analyzing the impact that drying pre-treatments had on honey quality. The application of pre-treatments has led to an increase in hydroxy-methyl-furfural by 39-71%, and a decrease in diastase activity by 17-36%, all compared to fresh honey samples. The solutions of Verma model proved to be the best fit with the experimental results.

The aim of this research was to study the impact of application technique and rate of liquid starter fertilizer applied with a novel device on the production of corn. Starter fertilizer was applied in the root system range of freshly germinated plants in the ‘belt’ and ‘point’ forms at different quantities (35, 50, 70, and 100 L ha⁻¹), which led to intensive plant growth in the initial stages of development. This adapted system was used for sowing and for application of the liquid starter fertilizer at the same time. The field trial was set up at two sites (two different land types), in the conditions of the natural water regime of the soil during the three vegetation seasons in the period 2016–2018. For this purpose, a prototype of the electronic device EUKU-01 was designed. The starter fertilizer was applied at 5 cm laterally from the row where the sowing was performed and 5 cm below the depth at which the corn seeds were sown. Data were statistically analyzed by two-factor analysis of variance, where the influence of mineral fertilizer treatment and the influence of liquid starter fertilizer treatment were observed as factors. The results showed that the optimal choice of the technique of liquid starter fertilizer application can result in fertilizer savings by 30% without reducing yield.