This research aimed to determine the effect of different harvesting times on the chemical composition of stinging nettle (Urtica dioica L.). The leaves of nettle were harvested at the same place once a month in the period of April–September 2019. The analysis focused on the contents of dry matter, soluble solids, ascorbic acid, titratable acidity, chlorophyll a and chlorophyll b, total carotenoids, total phenolic compounds, antioxidant activity, ash content, and macro- and microelements. The nettles harvested in April were characterized by the highest levels of soluble solids and some macro-and microelements (P, K, Fe, Zn). The plants harvested in May were distinguished for titratable acidity, chlorophyll a, chlorophyll b, and carotenoid contents. In this month, the plants were determined to have the highest antioxidant activity during the entire vegetation period. The plants collected in July contained the highest amount of Mn, but the antioxidant activity of these plants was the lowest during the vegetation period. In August, the plants had the highest levels of ascorbic acid, phenolic compounds, and ash, while the plants collected in September were characterized by having the highest amounts of Ca, Mg, and B as compared to those established in other months of vegetation.

Stinging nettle (Urtica dioica L.) is an herbaceous plant that grows all over the world and is widely used as an edible and medicinal plant. Overall research results reveal that the chemical content and antioxidant activity of aerial parts and roots of stinging nettle depends on the growing region, soil, meteorological conditions (especially sunshine), collecting time, etc. The chemical composition of stinging nettle growing in Lithuania and the solid–liquid extraction efficiency of leaves and roots using different solvents were analysed. Additionally, we determined leaves phenols extraction efficiency using 96% methanol at different extraction conditions. Research results showed that a higher amount of crude fats, non-nitrogen extractives, and total carotenoids were in leaves, but the amount of crude proteins and ash did not differ significantly compared with roots. A higher amount of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) were detected in roots instead of leaves while saturated fatty acids (SFAs) were in leaves. The extraction results showed that the most effective solvent for total phenols and flavonoids in leaves was 96% methanol, for total phenols in roots was 50% methanol and 50% ethanol for total flavonoids in roots. The most effective temperature for the Urtica dioica L. leaves phenols extraction was 70 °C, while time does not have a significant influence. The present study’s findings suggested that concentrated and binary solvents had different effects on the phenol’s extraction efficiency from different stinging nettle parts and extraction temperature performed a key role instead of extraction time.

This study aims to evaluate the ability of raspberry and blackberry pomace to inhibit lipid oxidation and prolong the refrigerated storage of beef patties. Berry pomace was incorporated into beef patties at the concentration of 1, 3, and 5%. Packed patties were stored for 9 days at 4 °C temperature and the quality of the meat was evaluated on the 0, 3rd, 6th, and 9th day. The natural mass loss during storage, the pH as well as the lipid oxidation were evaluated by thiobarbituric acid-reactive substance (TBARS) method. GC was used to determine the amount of fatty acids and e-nose, based on ultrafast gas chromatography, was used for the determination of volatile organic compounds in beef patties before and after the storage. The highest mass loss during refrigerated storage was observed in the control beef patties, while the berry pomace absorbed water and reduced the loss. The pomace additive influenced the decrease in the patties pH during the storage. Berry pomace can be very effective in relation to lipid oxidation, and as little as 1% of berry pomace influenced the decrease in the TBAR’s values in the patties stored for nine days by 3.06 and 2.42 times, depending on the pomace compared to the control patties. The use of berry pomace in meat products can reduce lipid oxidation, increase their fiber content and act as a thickener, as well as contribute to the usage of agri-food by-products.

(1) Background: Interest in plant analogues for food of animal origin is increasing. There are some pro-healthy food ingredients, such as odd-chain, cyclic, and branched fatty acids, that are perceived to be characteristic for food of animal origin or fermented. The purpose of the present study was to determine whether commercial plant drinks can be valuable nutrient mediums for the multiplication of lactic acid bacteria and yeasts. The goal was also to determine their potential for the production of the above-mentioned groups of fatty acids; (2) Methods: Commercial almond and oat beverages were used to produce 16 new variants of fermented beverages using 3 strains of lactic acid bacteria and 5 strains of yeasts. The apparent viscosity, volatile compounds (e-nose), and fatty acids composition (GC-MS) were analyzed; (3) Results: After 48 h of fermentation, acidity increased in both types of drinks. The gelation of proteins in the majority of the almond beverages increased the apparent viscosity. The highest content of minor fatty acids was determined in oat beverages fermented by Lactiplantibacillus plantarum PK 1.1 and Kluyveromyces marxianus KF 0001 and in the almond beverage fermented by Candida lipolytica CLP 0001. Among the used strains, Yarrowia lipolytica YLP 0001 was found to be a major producer of aromas in both beverages.

Oils derived from non-traditional seeds, such as safflower, milk thistle, and black cumin seeds, have recently grown in popularity. Seed oil is in high demand due to consumer interest in illness prevention and health promotion through healthier diets that include a high concentration of monounsaturated and polyunsaturated fatty acids and antioxidant phenolic components. This study assessed the quality characteristics of cold-pressed seed oil at three unique storage times: at the beginning of the trial (i.e., before storage), after 2 months, and after 4 months. The results of the performed analyses indicate that the acidity of extracted black cumin, safflower, and milk thistle seed oil fluctuates considerably over time. The highest acidity level change was detected for black cumin seed oil, from 10.26% after the extraction to 16.96% after 4 months of storage at 4 °C. Consequently, changes between pre- and post-storage peroxide concentrations were discernible after four months. Peroxide value in milk thistle and safflower seed oils increased by 0.92 meq/kg and 2.00 meq/kg, respectively, during the assessed storage time, while that of black cumin was very high and fluctuated. The storage period substantially affects oxidative changes and the oxidation stability of the oil. Major changes were observed in the polyunsaturated fatty acids in seed oil during storage. The essential changes were detected in the black cumin seed oil odor profile after 4 storage months. Their quality and stability, as well as the nature of the changes that occur during the storage of oil, require extensive investigation.

Phenolic compounds have a number of benefits to human health and can be used as preventive compounds for the development of some chronic diseases. Mentha plants are not only a good source of essential oils, but also contain significant levels of wide range of phenolic compounds. The aim of this research was to investigate the possibility to increase phenols content in Mentha plants under the foliar application with L-phenylalanine, L-tryptophan, L-tyrosine at two concentrations (100 mg L⁻¹ and 200 mg L⁻¹) and to create preconditions for using this plant for even more diverse purposes. Quantitative and qualitative analyses of phenols in mints were performed by HPLC method. Foliar application of amino acids increased the total phenol content from 1.22 to 3.51 times depending on the treatment and mint variety. The most pronounced foliar application to total phenols content was tryptophane especially in Mentha piperita “Swiss”. Mentha piperita “Swiss” was affected most by foliar application and the amount of total phenolic acids depending on the treatment ranged from 159.25 to 664.03 mg 100 g⁻¹ (DW), respectively, non-sprayed and sprayed with tryptophane 100 mg L⁻¹. Our results suggest that the biophenol content varies according to such factors as foliar application and variety, and every single mint variety has individual response to different applications of amino acids.