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The aim of the study was to analyze the process of roasting coffee beans in a convection–conduction roaster (CC) without a heat exchanger and a convection–conduction–radiation roaster (CCR) with a heat exchanger for determination of the aroma profile. The aroma profile was analyzed using the SPME/GC-MS technique, and an Agrinose electronic nose was used to determine the aroma profile intensity. Arabica coffee beans from five regions of the world, namely, Peru, Costa Rica, Ethiopia, Guatemala, and Brazil, were the research material. The chemometric analyses revealed the dominance of azines, alcohols, aldehydes, hydrazides, and acids in the coffee aroma profile. Their share distinguished the aroma profiles depending on the country of origin of the coffee beans. The high content of pyridine from the azine group was characteristic for the coffee roasting process in the convection–conduction roaster without a heat exchanger, which was shown by the PCA analysis. The increased content of pyridine resulted from the appearance of coal tar, especially in the CC roaster. Pyridine has an unpleasant and bitter plant-like odor, and its excess is detrimental to the human organism. The dominant and elevated content of pyridine is a defect of the coffee roasting process in the CC roaster compared to the process carried out in the CCR machine. The results obtained with the Agrinose showed that the CC roasting method had a significant effect on the sensor responses. The effect of coal tar on the coffee beans resulted in an undesirable aroma profile characterized by increased amounts of aromatic volatile compounds and higher responses of Agrinose sensors.

GABA (gamma-aminobutyric acid) and melatonin are endogenous compounds that enhance plant responses to abiotic stresses. The response of Vicia faba to different stressors (salinity (NaCl), poly ethylene glycol (PEG), and sulfur dioxide (SO2)) was studied after priming with sole application of GABA and melatonin or their co-application (GABA + melatonin). Both melatonin and GABA and their co-application increased leaf area, number of flowers, shoot dry and fresh weight, and total biomass. Plants treated with GABA, melatonin, and GABA + melatonin developed larger stomata with wider aperture compared to the stomata of control plants. The functionality of the photosynthetic system was improved in primed plants. To investigate the photosynthetic functionality in details, the leaf samples of primed plants were exposed to different stressors, including SO2, PEG, and NaCl. The maximum quantum yield of photosystem II (PS II) was higher in the leaf samples of primed plants, while the non-photochemical quenching (NPQ) of primed plants was decreased when leaf samples were exposed to the stressors. Correlation analysis showed the association of initial PIabs with post-stress FV/FM and NPQ. Stressors attenuated the association of initial PIabs with both FV/FM and NPQ, while priming plants with GABA, melatonin, or GABA + melatonin minimized the effect of stressors by attenuating these correlations. In conclusion, priming plants with both GABA and melatonin improved growth and photosynthetic performance of Vicia faba and mitigated the effects of abiotic stressors on the photosynthetic performance.

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The effects of different fertilizers and biofertilizers on crop production to increase plant growth, improve quality and yield components (dry leaves yield, leaf protein, and stevioside) of crops has been extensively studied. However, the combination of both types of fertilizers have rarely been investigated. To explore the effect of different fertilizers and biofertilizers on stevia plant, a two-year field experiment was conducted to investigate the growth response of stevia plants under the influence of nitrogenous fertilizers (NFs) and effective microorganisms (EM). The experiment was laid out in a split-plot design, with EM as the main plot factor (−EM and +EM) and NFs as the subplot factor [control, chemical NFs (Ch-N) and organic NFs (Org-N)]. The results showed that, plants treated with EM and Org-N showed 2-, 2.2-, 2.4-, 2.5-, 3.3- and 3-fold increases in plant height, number of branches, total leaf area, plant fresh weight, plant dry weight and leaf dry yield, respectively, compared to untreated plants. Similarly, plants receiving EM along with Ch-N showed 1.86-, 1.7-, 2.2-, 2.12-, 3-, and 2.72-fold increases in the same traits. Total chlorophyll, protein, N, P, K and sativoside contents were increased by 88.8, 152, 138, 151.5, 43 and 137.5% when EM and Org-N were applied to stevia plants. Application of EM together with Ch-N increased these properties by 0.5, 127.7, 115, 216, 42.6 and 83.8%, respectively in the same traits. Overall, the combined application of NFs and EM improved growth, yield and nutrient accumulation in stevia plants.