The influence of biostimulants (B) and nitrogen (N) fertilization on the yield and quality of onions were investigated. Experiments in the field with directly seeded (DS) onions and those from sets (FS) were carried out in 2021 in the Autonomous Province of Vojvodina (Serbia). HumiBlack^® (B1), Tifi^® (B2), and Agasi^® (B3) were used as B, and there was a control without B. Four N doses were used: 64, 100, 150 (standard dose), and 200 kg N/ha. The highest yields of DS onions (63.9 t/ha) and FS onions (52, 1 t/ha) were measured on treatment B2 × 150 kg N/ha. The highest total sugar content (80.6 g/100 g DM) was measured in FS onions under treatment B2 × 100 kg N/ha. Total nitrogen and protein content were the highest in DS onions treated with B2 × 200 kg N/ha, where total nitrogen was 2.3 g/100 g DM and protein content was 14.5 g/100 g DM. Depending on B and N, titratable acidity ranged from 1.7 to 3.6 g/100 g DM. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to analyze onions and showed that FS onions have lower values of total phenolics and crude fiber content, DPPH, FRAP, and ABTS compared to DS onions. In this study, a chemometric approach was suitable for grouping onions according to treatment effect and main interactions between B and N.

Mushrooms are a raw material rich in many nutritional compounds, and that is why a number of them are widely known as functional food. They contain fatty acids, carbohydrates, lycopene, sterols, lovastatin, trace elements, and other valuable compounds that show a wide range of properties, such as hepatoprotective, anticancer, antiviral, etc. For more efficient utilisation of mushrooms’ biologically active substances, widespread supercritical carbon dioxide extraction (Sc-CO₂) was used as an efficient way to isolate the high-value phytoconstituents from this type of raw material. Using Sc-CO₂, the extracts of five types of edible mushrooms—Lycoperdon saccatum, Pleurotus ostreatus, Craterellus cornucopioides, Russula Cyanoxantha and Cantharellus cibarius—were obtained. During the Sc-CO₂ process, the extraction time was reduced to 4 h compared to the prolonged process time applied in the typical traditional techniques (6–24 h). The extraction pressure (30 MPa) and temperature (40 °C) were constant. Fatty acids and the compounds of steroid structures were determined in the obtained extracts using GC–MS and GC–FID methods of analysis. The dominant compounds identified in the lipid extracts were fatty acids (linoleic, oleic, palmitic and stearic) and sterols (ergosterol, 7,22-ergostadienone and 7,22-ergostadienol). For complete insight into the process and to obtain the value of the extracts, chemometric analysis is provided. Principal component analysis (PCA) and hierarchical cluster analysis (HCA), as well as k-means clustering, showed that Craterellus cornucopioides was distinguished based on the extraction yield results.