The Asteraceae family is a large plant family, with over 1600 genera and 25,000 species, most of which are generally herbaceous plants. This family’s members are widely used in the human diet and medicine. One of the most popular representatives is Centaurea benedicta L., known as ‘Blessed Thistle’. It is a famous plant in the herbal world with some medical benefits, such as strong antioxidant and antidepressant effects, with antibacterial and antiseptic properties, a stimulant of appetite, with a good effect on the liver and the secretion of bile juices, etc. Therefore, this work aimed to fully characterize the chemical composition of the seeds of C. benedicta introduced in Bulgaria, some of the physicochemical characteristics, as well as the biologically active compounds. The main nutrient in the chemical composition was carbohydrates (68.5%), and half of their quantity was occupied by fibers (32.2%). Total proteins accounted for 16.4%, and the glyceride oil content was rather low—about 11.0%. The main fatty acids identified in the seed oil were linoleic (72.1%) and oleic acids (18.1%), and the amount of the polyunsaturated ones predominated (73.0%). The main lipid-soluble bioactive components were sterols (0.9%), phospholipids (1.9%), and tocopherols (492 mg/kg). β-Sitosterol (59.5%) and stigmasterol (19.4%) were the main sterols, and α-tocopherol (472 mg/kg) predominated in the tocopherol fraction. The major phospholipids were phosphatidylethanolamine (45.4%), followed by phosphatidylinositol (37.1%) and phosphatidylcholine (6.1%).

The investigation aims to elucidate the bioactive constituents present in waste seeds derived from Nicotiana tobacum L., there by contributing to a more holistic comprehension of the health-related implications associated with tobacco plants beyond conventional consumption concerns. Waste seeds from tobacco plants N. tobacum L. were grown during harvest 2021-2022 at the Tobacco and Tobacco Products Institute (part of Bulgarian Agriculture Academy). Chemical analysis of tobacco waste seeds (TWS) encompassed the examination of primary metabolites including lipids (32.1±1.0%), proteins (29.4±1.4 %), and carbohydrates (27.6±0.5 %). Furthermore, various lipid indices (Atherogenicity, Thrombogenicity, Hypocholesterolemic/ hypercholesterolemic, etc.) were computed utilizing the fatty acid composition of the oil extracted from tobacco waste seeds. The results showed that TWS could be utilized with health benefits-seeds are a good resource for n-6 fatty acids (linoleic acid-71.94±1.05 %) with good atherogenicity and thrombogenicity qualities and natural antioxidants.

This study aimed to determine the total phenolic content of Oriental tobacco waste seeds, grown under organic production, and to evaluate their antioxidant activity by extraction with different solvents under different conditions. The extraction was performed with H2O, 99.9% CH3OH, 60% CH3OH, and 96% C2H5OH under maceration and ultrasonic extraction at 20°C and 40°C. All solvents were used in a volume of 4 mL, 5 mL, and 6 mL. The total phenolic content varied between 0.89 mg/g GAE (maceration; sample/solvent ratio 0.1g/5mL, C2H5OH) and 5.85 mg/g GAE (maceration; sample/solvent ratio 0.1g/6mL, C2H5OH). Ethanolic and 60% methanolic extracts had the highest antioxidant activity as determined by the DPPH method; 60% methanolic and water extracts had the highest antioxidant activity as determined by the ABTS method; while methanolic and 60% methanolic extracts had the highest antioxidant activity as determined by the FRAP method. In addition, the content of nicotine in tobacco seed extract was not detected.

Tobacco seeds (Nicotiana tabacum L.) represent a promising nicotine-free source of bioactive compounds, particularly polyphenols and natural antioxidants. This study evaluated the total phenolic content (TPC) and antioxidant activity of tobacco seeds, defatted seed cake, and seed oil obtained from oriental tobacco varieties cultivated under organic and conventional conditions over two consecutive years (2020–2021). Extracts from tobacco seed-derived products were prepared using different solvents (water, 60% methanol, 80% methanol, 80% ethanol, and 95% ethanol). TPC was determined by the Folin–Ciocalteu method, while antioxidant capacity was assessed by DPPH, ABTS, and FRAP assays. In addition, the Relative Antioxidant Capacity Index (RACI) and the Phenolic Antioxidant Coefficient (PAC) were applied to compare the antioxidant performance of the different samples and to estimate the contribution of phenolic compounds to the overall antioxidant activity under the two cultivation conditions. The results showed that extraction efficiency strongly depended on solvent polarity, with 60% methanol providing the highest recovery of phenolic compounds from seeds and seed cake, while 80% ethanol was more effective for oil. Seed cake extracts exhibited higher TPC (1.15 ± 0.04 mg GAE g⁻¹–3.98 ± 0.10 mg GAE g⁻¹) and antioxidant activity than seed extracts (0.070 ± 0.04 mg GAE g⁻¹–2.02 ± 0.02 mg GAE g⁻¹) and oil (0.29 ± 0.01 mg GAE g⁻¹–1.70 ± 0.17 mg GAE g⁻¹), indicating enrichment of phenolic compounds after oil removal. Among the tested extraction conditions, 95% ethanol and 60% methanol extracts showed the strongest antioxidant potential, with maximum FRAP (23.10 mM TE g⁻¹), DPPH (3.35 mM TE g⁻¹), and ABTS (14.70 mM TE g⁻¹) values depending also on variety and harvest year. Organically produced samples showed higher TPC and RACI values than conventionally produced materials, while PAC analysis revealed the strongest association between phenolic compounds and antioxidant capacity in the FRAP assay. These findings provide a comparative evaluation of the antioxidant potential of tobacco seed-derived fractions and the effectiveness of the extraction methods used for their recovery.

The study aimed to investigate the content of tar and nicotine in the particle phase, and the carbon monoxide (CO) and carbonyl compounds in the gas phase of tobacco smoke from organically and conventionally grown tobacco. The nicotine content in organically grown tobacco was lower than that in conventionally grown tobacco, while the tar and CO were higher. The total carbonyl content in gas-phase in organically grown tobacco is almost equal to that of conventionally grown tobacco. A good correlation between total sugars and acetaldehyde, total sugars and propionaldehyde, and total sugars and 5-hydroxymethylfurfural (5-HMF), was observed, whereas a weaker correlation was observed between glycerol and acetaldehyde, glycerol and propionaldehyde.

The present study aimed to investigate the performance of two green solvents (2-methyloxolane (2-MeOx) and d-limonene) for the extraction of glyceride oil from tobacco seeds. Glyceride oil was isolated by three extraction methods with both solvents—Soxhlet extraction, maceration, and ultrasonic-assisted extraction. Soxhlet extraction with 2-MeOx gave the highest oil yield (35.0%), while maceration and ultrasonic methods resulted in lower yields (~25%). Tobacco seed oil extracted with 2-MeOx was rich in unsaturated fatty acids (69.2–84.0%), with linoleic acid predominating (38.0–68.5%). Soxhlet extraction with d-limonene resulted in the highest yield of glyceride oil (47%), while maceration and ultrasonic extraction produced 16% and 23%, respectively. Previous studies by the research group showed that Soxhlet extraction with n-hexane yielded 38.4 ± 0.5% oil. The fatty acid composition of oils obtained with d-limonene differed depending on extraction type—Soxhlet extraction showed higher saturated fatty acids (69.4%), whereas maceration and ultrasonic extraction produced a more unsaturated profile (57.4% and 72.4%, respectively). Ultrasonic extraction with both solvents generated oils approaching the ideal saturated: monounsaturated: polyunsaturated ratio. Lipid index evaluation indicated that oils extracted with 2-MeOx exhibit a healthier but thermally sensitive profile, while d-limonene oils are more stable and suitable for storage and processing.