Effects of Organic and Mineral Fertilization on Yield and Selected Quality Parameters for Dried Herbs of Two Varieties of Oregano (Origanum vulgare L.)

Phytochemical Characterization and Biological Activities of Essential Oil from Satureja montana L., a Medicinal Plant Grown under the Influence of Fertilization and Planting Dates

The rising demand for safe plant compounds and herbal products that contribute positively to human health is in line with current market trends. Plants belonging to the Satureja genus, particularly the aromatic medicinal S. montana L. from the Lamiaceae family, are well suited to these trends as they serve as pharmaceutical raw materials. This research aimed to assess the influence of sowing date and fertilization doses, as well as their interaction, on the fresh weight, essential oil content, and composition of S. montana. Experimental cultivation involved varying nitrogen and phosphorus levels. The second cut had the highest fresh weight and oil production compared to the first cut. The highest total plant biomass was achieved with autumn sowing and fertilization at 55 kg N/ha and 37 kg P/ha, whereas Spring sowing exhibited higher essential oil production, with the maximum oil % with 74 kg P/ha and oil yield after applying 55 kg N/ha and 74 kg P/ha. The GC-MS analysis revealed that carvacrol was the predominant compound, with it being recommended to grow S. montana in Spring at doses of 55 kg N/ha and 74 kg P/ha for the superior oil yield. Additionally, S. montana essential oil demonstrated notable biological and antimicrobial activity, positioning it as a potential alternative to chemical food preservatives.

Green manure (Crotalaria juncea L.) enhances Origanum vulgare L. biomass accumulation, essential oil yield, and phytochemical properties

Green manure (GM) may reduce the use of chemical fertilizers, been an ecologically appropriate strategy to cultivation of medicinal plants. Crotalaria juncea, is one of the most used because it adapts to different climatic and high nitrogen content. Origanum vulgare. is widely used in cooking, pharmaceutical, cosmetic industries and food products. The objectives of this study were to evaluate the GM on biomass, essential oil (EO), phenolic and antioxidant. The experiment consisted: control; 150, 300, 450, and 600 g (Sh= leaves+steam) more 200 g roots (R); 600 g aerial part; 200 g roots; and soil with 300 g cattle manure per pot. The highest dry weights were observed in the presence of GM and cattle manure (90 days). The control had an EO production 75% lower in relation to the dose of 450 g GM (Sh+R). Principal component analysis showed that GM and cattle manure positively influenced the dry weight, content, yield, and EO constituents, and total flavonoids. The GM contributed to the accumulation of the major EO compounds (trans-sabinene hydrate, thymol, terpinen-4-ol). The GM management may be beneficial for cultivating, because it can increase the production of biomass and the active components, in addition to being an inexpensive resource.

A Long-Term Study on Chemical Compounds and Their Location in Sweet Basil Leaves from Organic and Conventional Producers

Bioactive compound profiles in organic and conventional sweet basil were analyzed by HPLC, and the enzymatic status and antioxidant status of plants cultivated with the two systems were also examined. Fluorescence microscopy was used for the determination of compounds' locations in the basil leaves. The experiment was conducted from 2019 to 2021. Organic and conventional basil samples were obtained directly from Polish herb producers. The results showed that the chemical profiles of organic and conventional basil leaves are different. Not only the cultivation method but also the experimental year had a significant impact on the antioxidant content in basil leaves. Organic basil contained significantly more dry matter (11.97 g 100 g-1 FW) compared to conventional one (10.54 g 100 g-1 FW) and a higher tendency for total phenolic compounds (5.24 mg g -1 DW) accumulation. The higher bioactive compound content reflects the antioxidant activity (61.0%, 54.33%, and 46%) in organic basil compared to conventional (46.87%, 38.055, and 39.24%) with respect to the analysis method (ABTS, DPPH, and FRAP). Catalase activity (39 µmol H2O2 min-1 mg-1) in organic basil was higher compared to conventional (23.19 µmol H2O2 min-1 mg-1) ones. The obtained results are very unique and could be used by herb producers as a key for high-quality basil production. The higher concentration of bioactive compounds in organic basil gives a better nutraceutical status to this popular herb.

Variability of Properties Modulating the Biosynthesis of Biologically Active Compounds in Young Barley Treated with Ozonated Water

This paper presents the effects of irrigating barley plants with different type of water solutions saturated with gaseous ozone generated from atmospheric air. The study investigated the effects of the applied types of water on the modulation of the biosynthesis of selected bioactive compounds (content of total polyphenols, small molecule antioxidants, vitamin C) in the produced plant material. A number of transformations of reactive oxygen species (ROS) and nitrogen compounds have also been postulated; these are observed during the saturation of water with gaseous O₃ and 30 min after the end of the process. It was shown that after the process of water saturation with gaseous O₃, the gas later is converted to compounds with high oxidative potential and good stability; these, in turn, lead to the oxidation of oxidates generated from atmospheric nitrogen into nitrates, which exhibit fertilising properties. Thirty minutes after the process of H₂O saturation with gaseous O₃ was completed, the tests showed the highest concentrations of nitrates and the relatively high oxidative potential of the solution originating from H₂O₂ with a low concentration of the dissolved O₃. This solution exhibited the highest activity modulating the biosynthesis of polyphenols, small molecule antioxidants and vitamin C in young barley plants. The resulting differences were significant, and they were reflected by 15% higher total polyphenol content, 35% higher antioxidative potential and 57% greater content of vitamin C compared to the control specimens (plants treated with fresh H₂O).

The Modification of Substrate in the Soilless Cultivation of Raspberries (Rubus Idaeus L.) as a Factor Stimulating the Biosynthesis of Selected Bioactive Compounds in Fruits

Raspberry fruits are a valuable source of bioactive compounds. The study used the modification of the substrate (coconut fibre), consisting of the use of various organic and mineral additives, in the soilless cultivation of raspberries. The additives influenced the biosynthesis of bioactive compounds in the raspberry fruits by modifying the sorption properties and the abundance of the substrate. The influence of the additives on the content of polyphenols was determined as well as their profile (UPLC-MS), antioxidant potential (ABTS), vitamin C content, and the activity of selected enzymes that are markers of stress and resistance to abiotic factors. In the study, a significant effect of these additives was observed on the biosynthesis of polyphenols in raspberry fruit. The highest increase in the content of these compounds in relation to the control sample (substrate-100% coconut fibre), namely 37.7%, was recorded in the case of fruit produced on coconut substrate enriched with sheep wool. These fruits were also characterised by a significantly different profile of these compounds. These changes were caused by readily available ammonium nitrogen and free amino acids in the decomposition of proteins contained in the sheep wool. This was confirmed by the recorded content of chlorophyll SPAD in the plant leaves and the activity of selected enzymes, which proves a low level of stress and good condition of the plants.

Induction of Biosynthesis Antioxidant Molecules in Young Barley Plants by Trioxygen

Young barley plants are a good source of bioactive compounds. This paper presents the effects of gaseous O3 (trioxygen or ozone) on the biosynthesis of compounds, determining the antioxidant potential of young barley plants. The total content of polyphenols was determined along with their profile, as well as total antioxidant potential and vitamin C content. The highest contents of these compounds were identified in young barley plants exposed to gaseous O3. The main bioactive compound, representing polyphenols, determined in the examined raw materials was saponarin (isovitexin 7-O-glucoside). The induction of increased biosynthesis of these molecules was directly linked to the modification of the activity of selected enzymes. The increased polyphenol content resulted from the modified activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). On the other hand, the oxidative effect of ozone on barley plants was reduced, owing to the modified activities of catalases (CAT), glutathione peroxidases (SOD) and guaiacol peroxidase (GPOX). Analysis of the results showed that by applying gaseous O3 at a dose of 50 ppm for 10 min, the contents of bioactive compounds can be maximised in a residue-free way by activating oxidative stress defence mechanisms.

Effects of Post-Harvest Ozone Treatment on Some Molecular Stability Markers of Amelanchier alnifolia Nutt. Fruit during Cold Storage

Fruits of Amelanchier alnifolia Nutt. ex M. Roem. (Nutt.) are a good source of bioactive compounds and vitamins. Due to the fact that the berries are a soft fruit, they require special procedures to increase their molecular and mechanical stability during cold storage. The study investigated the effects of ozone treatment applied cyclically (every 24 h) on selected chemical and mechanical parameters of saskatoon berries kept in storage. For this purpose, measurements were performed to assess changes in some molecular markers such as antioxidant potential, content of vitamin C, and total polyphenols, as well as microbial stress and maximum destructive force under uniaxial compression of samples. The effectiveness of the storage process was also assessed in relation to the conditions used by determining the proportion of fruit affected by diseases occurring in storage. The findings show that ozone treatment led to increased content of bioactive compounds at the initial stages of storage and resulted in decreased loss of water and bioactive compounds at the later stages. Ultimately, irrespective of the conditions applied during ozone treatment, it was observed that the growth of micro-organisms on the fruit surface was inhibited, and as a result, storage losses during the relevant period were significantly reduced.

Multidimensional exploration of essential oils generated via eight oregano cultivars: Compositions, chemodiversities, and antibacterial capacities

Numerous species of Origanum (Lamiaceae) have been widely used as spices to extend the shelf life of foods. Essential oils extracted from this genus have attracted much attention owing to their potential applications as bactericides. Here, we evaluated the chemical compositions of eight oregano essential oils (OEOs) using gas chromatography-mass spectrometry and assessed their antibacterial activities. The chemical compositions of OEOs were affected by the cultivar factor, and seven common compounds, including carvacrol, were identified among eight OEOs. Partial least squares discriminant analysis enabled the distinction of three groups among these OEOs, as characterized by the proportions of carvacrol, thymol, and sesquiterpenes. OEOs effectively inhibited Escherichia coli and Staphylococcus aureus with varying antibacterial activities. Spearman correlation network highlighted core antibacterial contributors in the chemical profiles of OEOs. Our results revealed that the bacteriostatic effects of OEOs could be explained by core compounds and their synergistic effects.

Characterisation of Some Phytochemicals Extracted from Black Elder (Sambucus nigra L.) Flowers Subjected to Ozone Treatment

Elderflowers are a well-known source of bioactive compounds. The amount of isolated bioactive compounds may be increased by applying various abiotic and biotic factors. Gaseous ozone (10 and 100 ppm) was used in the process of preparing flowers. Next, the flowers were treated with sugar syrup to extract bioactive compounds. It was shown that this treatment, including the influence of extraction temperature, significantly affects the contents of polyphenols (liquid chromatography-mass spectrometry (LC-MS) methods) and vitamin C, as well as the antioxidant potential (cupric reducing antioxidant capacity (CUPRAC method)), the profile of volatile substances (head space-solid-phase microextraction (HS-SPME methods)) and the colour of the syrup (Commission Internationale de l'Eclairage (CIE) L*a*b* methods). The findings show that an increased dose of ozone and higher extraction temperature applied in the process of syrup production resulted in higher contents and different compositions of bioactive compounds. The highest contents of bioactive compounds were identified in syrup obtained from raw material treated with ozone for 15 min (concentration = 10 ppm) and extraction with sugar syrup at a temperature of 60 °C.

Effect of Ozone Treatment on the Quality of Sea Buckthorn (Hippophae rhamnoides L.)

The aim of this research was to show the effect of the ozonation process on the quality of sea buckthorn (Hippophae rhamnoides L.). The quality of the ozonated berries of sea buckthorn was assessed. Prior to and after the ozone treatment, a number of parameters, including the mechanical properties, moisture content, microbial load, content of bioactive compounds, and composition of volatile compounds, were determined. The influence of the ozonation process on the composition of volatile compounds and mechanical properties was demonstrated. The ozonation had negligible impact on the weight and moisture of the samples immediately following the treatment. Significant differences in water content were recorded after 7 days of storage. It was shown that the highest dose of ozone (concentration and process time) amounting to 100 ppm for 30 min significantly reduced the water loss. The microbiological analyses showed the effect of ozone on the total count of aerobic bacteria, yeast, and mold. The applied process conditions resulted in the reduction of the number of aerobic bacteria colonies by 3 log cfu g-1 compared to the control (non-ozonated) sample, whereas the number of yeast and mold colonies decreased by 1 log cfu g-1 after the application of 100 ppm ozone gas for 30 min. As a consequence, ozone treatment enhanced the plant quality and extended plant's storage life.

Influence of Agronomic Practice on Total Phenols, Carotenoids, Chlorophylls Content, and Biological Activities in Dry Herbs Water Macerates

Oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) have long been known for their organoleptic properties. Both plants are widely used in cuisine worldwide in fresh and dried form and as a pharmaceutical raw material. The study aimed to assess if the type of cultivation influenced chosen chemical parameters (total polyphenols by Folin-Ciocalteu method; carotenoids and chlorophyll content by Lichtenthaler method), antimicrobial activity (with chosen reference microbial strains) and shaped cytotoxicity (with L929 mouse fibroblasts cell line) in water macerates of dry oregano and thyme. Polyphenols content and antimicrobial activity were higher in water macerates obtained from conventional cultivation (independently from herb species), unlike the pigments in a higher amount in macerates from organic herbs cultivation. Among all tested macerates stronger antimicrobial properties (effective in inhibiting the growth of Pseudomonas aeruginosa, Bacillus cereus and Salmonella enteritidis) and higher cytotoxicity (abilities to diminish the growth of L929 fibroblasts cytotoxicity) characterized the conventionally cultivated thyme macerate.

Effects of Ozone Treatment on Microbial Status and the Contents of Selected Bioactive Compounds in Origanum majorana L. Plants

This study presents the effects of ozone treatment on microbial status and contents of selected bioactive compounds in marjoram plants. Origanum majorana L. is a widely used plant which in the course of production is affected by microbial infections. One of the ways to reduce microbial load involves application of a strong oxidant, such as ozone. In order to determine the effects of ozonation, a number of analyses were carried out including microbiological tests (aerobic colony count, yeast and mould count, and mesophilic lactic acid bacteria count) and chemical tests assessing total antioxidant potential, total polyphenols, and volatile fraction composition. Ultimately, the findings showed considerable (6-log) reduction in microbial load, with unchanged composition of headspace volatile compounds. Furthermore, the raw material obtained presented elevated the contents of the selected bioactive compounds. It was shown that the most beneficial effects are achieved when ozone treatment is applied at a rate of 1 ppm for a duration of 10 min.

Ozone Treatment as a Process of Quality Improvement Method of Rhubarb (Rheum rhaponticum L.) Petioles during Storage

The aim of the study was to identify the effects of ozone treatment reflected by the microbial, mechanical properties and selected chemical parameters during the storage of rhubarb petioles. For this purpose, after they were harvested, rhubarb petioles were treated with gaseous ozone at concentrations of 10 and 100 ppm, for the duration of 5, 15 and 30 min. Subsequently, the plant material was stored at room temperature for 14 days. After this time, the raw material was subjected to a number of chemical and mechanical tests. It was shown that the rhubarb petioles treated with ozone at a rate of 100 ppm for 30 min were characterized by the lowest loss of water content. It was also found that, compared to the control, most samples subjected to ozone treatment presented better mechanical properties, as well as higher oxidative potential and contents of polyphenols and vitamin C. Based on these findings, it was determined that ozone treatment largely increases storage stability of rhubarb.