Functional beverages enriched with herbal extracts are gaining popularity due to their potential health benefits. Tilia cordata flowers are known for their antioxidant and antimicrobial properties, making them a promising additive in food and beverage formulations. Our study aimed to develop ready-to-drink iced teas enriched with T. cordata flower extracts and to evaluate their antioxidant, antimicrobial, and sensory characteristics as functional food products. Fresh T. cordata flowers were analyzed for metal contents. Phenolic acid profiles in ethanolic and aqueous extracts were determined using HPLC-MS. Antioxidant activity was evaluated using DPPH radical scavenging, conjugated diene, and iron ion chelation assays. Antimicrobial effects were tested against Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes. Sensory analysis was conducted using AI-based facial expression recognition to assess consumer responses. Metal analysis revealed low concentrations of Mn, Zn, Cu, and Fe, with no detectable Pb, Cd, or Ni. Ethanolic extracts showed significantly higher levels of phenolic acids than aqueous extracts. Iced teas containing both types of extracts demonstrated strong antioxidant activity, with ethanolic formulations having the highest levels of phenols and flavonoids. Antimicrobial tests confirmed activity in both teas, with ethanolic extracts showing stronger effects. Sensory analysis indicated positive emotional responses and consumer acceptance for both formulations. Iced teas enriched with T. cordata extracts exhibited significant antioxidant and antimicrobial properties, confirming their potential as functional beverages. The use of AI-driven sensory evaluation proved effective in capturing consumer preferences, supporting its application in product development. These findings suggest commercial viability for industrial production.
Rural settlements in Serbia are increasingly exposed to the combined pressures of demographic decline and climate-related hazards. This study integrates Geographic Information Systems (GIS), Remote Sensing (RS), census data, gridded population datasets, and climate projections to assess long-term rural vulnerability through 2100. Historical census information spanning 1948–2022 provides the demographic context, while the 1991 and 2022 rural populations are used for the baseline demographic projection. Landsat 8/9, Sentinel-2, hazard-event databases, and CMIP6-MIROC6 climate projections under SSP5-8.5, downscaled using CHELSA, are integrated in the spatial analysis. A dimensionless Climate-Hazard Exposure Index (CHEI), based on normalized drought, flood, extreme-rainfall, and temperature scores, and a Settlement Viability Index (SVI) are used to identify areas where demographic decline coincides with elevated climate-hazard exposure. The baseline demographic model estimates a reduction of the rural population from approximately 2.1 million inhabitants in 2022 to 1.44 million by 2050 and about 730,000 by 2100. Climate exposure is treated as an independent spatial layer rather than as a calibrated causal coefficient of population decline. Severe demographic viability risk is operationalized using a projected settlement population threshold of fewer than 100 inhabitants. The spatial classification achieved an overall accuracy of 80.0%, with precision of 83.0%, recall of 80.0%, and an F1-score of 81.5%. Demographic hindcasting is interpreted as an internal agreement check rather than independent predictive validation. Southern and eastern Serbia show the highest combined vulnerability, supporting the need for targeted adaptation, climate-resilient infrastructure, and sustainable rural-development policies.
This study investigates a sustainable route for biodiesel production from waste plum kernel oil (PKO) using a heterogeneous, waste-derived catalyst (35% CaO supported on coal fly ash-derived zeolite), in the presence of a green deep eutectic solvent (DES), triethanolamine:menthol (TEA:M, 1:2 mol/mol), as a cosolvent. The catalyst exhibited a high specific surface area, developed porosity, and abundant strong basic sites, ensuring effective transesterification activity. PKO, characterized by low acid value (1.95 +/- 0.03 mg KOH/g) and high oleic acid content (73.8 +/- 2.5%), proved to be a suitable feedstock for biodiesel production. The incorporation of TEA:M DES into the reaction system significantly enhanced fatty acid methyl ester (FAME) formation by improving mass transfer during the initial reaction period. Transesterification was conducted at 60 degrees C under atmospheric pressure by varying the catalyst amount (2-10% based on oil mass), DES amount (1-9% based on oil mass), and methanolto-oil molar ratio (6:1-12:1 mol/mol). A maximum FAME content of 96.7% was achieved under optimized reaction conditions (8% catalyst, 5% DES, 6:1 methanol-to-oil ratio). Transesterification followed a pseudo-firstorder kinetics with rate constants of 0.032-0.152 min(-1) and an activation energy of 42.67 kJ/mol. The catalyst maintained high activity over five reuse cycles, with only a slight decrease in FAME content from 96.7 +/- 1.0% to 94.5 +/- 0.5%. Cost analysis confirmed process feasibility ((sic)1.24/kg), demonstrating the potential of integrating waste-derived catalysts with green cosolvents for sustainable biodiesel production and providing a promising pathway toward a circular economy.
Industrial hemp (Cannabis sativa L.) production and the hemp-based industry are set for expansion. Hemp is cultivated for valuable fibers from stems and oil from seeds, used in various industrial applications. Recently, hemp has been grown for energy production due to its high biomass and seed yields. Hemp oil is suitable for biodiesel production through transesterification, while hemp biomass serves as a solid fuel or raw material for bioethanol, biohydrogen, and biogas production. This paper provides a comprehensive review of hemp seed and biomass pretreatment, oil extraction, and biofuel production methods. Pretreatment methods for hemp seed and biomass are largely unexplored, and innovative methods require detailed economic analysis before commercialization. Research on hemp oil extraction is sparse and lacks comparative analyses of different techniques regarding yield and quality. Advanced methods yield more oil in shorter times than conventional techniques. Advanced solvent extraction yields more oil than screw pressing and maceration but less than Soxhlet extraction. Transesterification of hemp oil for biodiesel typically uses base catalysts, either homogeneous or heterogeneous, but novel methods have yet to be applied. Other biofuels are produced by thermochemical (torrefaction, pyrolysis, gasification) and biological (fermentation, anaerobic digestion) processes. A comparative analysis of biofuel yields and primary energy recovery potentials of different hemp components is needed to optimize biomass utilization in bioenergy production. Despite the substantial benefits of hemp biofuel production, challenges such as legal and regulatory barriers, economic competition with high-value products, production costs, environmental trade-offs, technological advancement, and public perception need to be addressed.
We present characterization of atmospheric pressure Ar streamer jet, diagnostics of physico-chemical properties of Plasma Activated Water (PAW), and modeling of Reactive Oxygen and Nitrogen Species (RONS) deposited in PAW. Additional focus is on the toxicity of the created PAW to model plant Lemna minor. The streamer jet is characterized by analyzing electrical properties, gas-phase characteristics through plasma emission, and laser-induced fluorescence of OH(X) radicals. Measured OH densities are in the range of 10(20) m(-3) depending on the mean power deposited to plasma. Gas phase species are linked to measured RONS concentrations, while modeling results confirmed the production mechanisms of H2O2, NO2- and NO3- species. Experiments with Lemna minor show both favorable and negative effects of PAW depending on the PAW concentration.
