Search Results (465)

Microalgae are a promising third-generation biomass resource due to their high photosynthetic efficiency, rapid growth rates, capacity to accumulate energy-rich biochemical fractions, and efficient utilisation of carbon dioxide (CO₂). In this study, the effect of illumination colour on the growth and energetic properties of Chlorella vulgaris cultivated in laboratory-scale photobioreactors was investigated. Four independent cultivation cycles were conducted under controlled conditions using a 16 h light/8 h dark photoperiod, temperatures of 20–30 °C, and aeration with air enriched with 10% CO₂. Cultures were illuminated using six light colours: plant-specific, white, green, red, blue, and ultraviolet. Biomass productivity was quantified, and the higher heating value (HHV) of the produced biomass was determined by bomb calorimetry. In addition, proximate (technical) analysis was performed for Chlorella vulgaris and compared with Chlorella pyrenoidosa, Spirulina, and Fucus vesiculosus (bladderwrack). The results showed that white illumination promoted both the highest biomass growth and the highest HHV for Chlorella vulgaris (15.08 MJ·kg⁻¹), while ultraviolet illumination had a disruptive effect, leading to the lowest growth and calorific value (11.49 MJ·kg⁻¹). Comparative analysis revealed that Chlorella pyrenoidosa exhibited the most favourable energetic properties; however, Chlorella vulgaris remains attractive for cultivation due to its robustness and broad tolerance to operating conditions. Full article

Algae extracts have emerged as a sustainable and eco-friendly alternative to synthetic dyes and functional additives in the textile industry, particularly for dyeing and functionalizing of cotton fabrics. Herein, two types of water-soluble algae extracts from Arthrospira platensis and Porphyridium cruentum were characterized in terms of thermal, structural, and functional properties and used as dye and/or functional agents. Cotton samples were pre-treated with chitosan and alum mordants and compared with commercially treated cationic cotton. The algae extracts were applied through the exhaust method, with variations in temperature, pH, liquor ratio, temperature rise gradient, and extract percentages. The resulting colours, assessed through CIE L*a*b* coordinates and K/S values using UV–Vis spectroscopy, displayed green and pink coloration, with commercial cationic cotton exhibiting more intense colours. Colour fastness measurements were also performed on functionalized cotton fabrics. The water-based algae extracts and functionalized samples were additionally characterized for functional features, displaying an antioxidant activity exceeding 60% (68.13 ± 3.60 and 60.76 ± 1.18, for A. platensis and P. cruentum, respectively). This work highlights their dual role in providing both aesthetic dyeing and functional enhancement of cotton. By using renewable marine resources and eco-friendly water-based processes, this approach supports the development of greener, more sustainable textile technologies. Full article

The background modification of ecosystems affected by fire can cause black or dark colours in animals to become adaptive, providing better protection against visually oriented predators. We surveyed fire-prone Mediterranean woodlands to describe the behaviour, position and background characteristics of the black cicada Tibicina quadrisignata Hagen, 1855 found in recently burnt and unburnt trees. A human detectability test, using cicada pictures in natural backgrounds taken during the fieldwork, was used to assess detection risk. Most cicadas found were solitary males uttering courtship song. Many cicadas flew when approached, with 82% of flight initiation distances being less than 3 m and half of the flights being less than 30 m. Cicadas favoured sunny locations in early morning, and shady sites as the temperature increased. Fire altered fine-scale microhabitat use by cicadas, since cicadas were found in 71% thicker stems and at 14% lower height on the tree, in burnt trees, in relation to unburnt trees. Generalised Linear Mixed Models (GLMMs) revealed a negative fire effect on cicada detection by human test participants. The probability of detection fell from 0.62 in unburnt backgrounds to 0.48 in burnt backgrounds, while the time needed for detection did not change between burnt and unburnt sites. Overall, these results show that T. quadrisignata cicadas adjust their substrate use after fire and are less detectable on burnt backgrounds. Real predation risk, however, also depends on thermoregulation-associated exposure, courtship song activity and predator densities. Full article

Background/Objectives: We investigated whether ingestion of caffeine (~1 h before) was beneficial to subsequent morning (07:30 h), mood, strength and cognitive measures. Methods: Fourteen recreationally active males were recruited and completed six sessions: (i) one repetition maximum (1RM) for bench press and back squat; (ii) two familiarization sessions of strength measures; (iv) three experimental conditions administered in a double-blinded, randomized counterbalanced design order, either caffeine (Caffeine [CAFF], 300 mg or 2.8–4.3 mg/kg body weight), placebo (Placebo [PLAC]) ingested at 06:30 h, or no-pill control (No Pill [NoPill]). For each experimental session, on arrival at the laboratory, rectal and skin temperature were measured as well as a battery of cognitive performance through a battery of tests (trail-making test, Rey’s auditory verbal learning test, and Stroop word–colour interference test). Thereafter, maximum voluntary contraction on an isometric chair (MVC) without and with stimulation was conducted, and three repetitions were performed at 40, 60 and 80% of 1RM for bench press and back squat. Average power (AP), average velocity (AV), peak velocity (PV), mean propulsive velocity (MPV), average acceleration (RDV), displacement (D) and time-to-peak velocity (tPV) were recorded using MuscleLab linear encoders. Rating of perceived exertion and effort was asked after each set (RPE). The data was analysed using a general linear model with repeated measures. Results: MVC peak-force values with and without stimulation showed a significant increase in the CAFF condition compared to values for NoPill and with stimulation PLAC conditions (stim: Δ9.0 and 8.7%; no stim: 8.3%; p < 0.05; η²_p = 0.33 and 0.42). Greater muscle % activation was achieved for the CAFF than the other conditions (~6%, p ≤ 0.042; η²_p = 0.33). In the non-stimulated MVC, RPE was perceived as easier (4.8%, p = 0.04). AV and MPV values were higher in both bench press (Δ3.3 and 4.6%) and back squat (Δ7.7 and 9.2%) in CAFF than the PLAC condition (p = 0.031; η²_p = 0.24 and 0.23 and 0.24 and 0.32). CAFF improved auditory total recall compared to NoPill (9.5%, p = 0.040; η²_p = 0.22). Conclusions: Early morning ingestion of caffeine improved MVC to levels observed by others in the evening, as well as some aspects of bench press, back squat and recall performance. Caffeine ingestion had no effect on core temperature, mood, tiredness, alertness or other measures of cognitive performance. Full article

This study investigated the effects of microwave irradiation on the particle size distribution, rheological properties, fluorescent characteristics, and sensory characteristics of wine. Wine samples were treated under varying microwave power (100–500 W), temperature (20–60 °C), and time (1–5 min). Results indicated that microwave treatment modified the particle size distribution, especially the proportion of particles in the range of 0.3–0.5 μm, which increased with microwave power, temperature, and time. Rheological analysis indicated that the behaviour followed the Power-law model, with all samples exhibiting expansion fluid properties (n > 1). Fitting with the Casson model revealed that microwave treatment increased the yield stress (τ₀) and viscosity coefficient (K), with optimal improvements observed at 300 W, 30 °C, and 3 min (τ₀ = 0.7769 Pa, K = 2.9367 × 10⁻³ Pa s^0.5). These changes contributed to enhanced leg phenomenon and thickening effect. Furthermore, microwave treatment elevated the fluorescence intensity of wine, indicating accelerated formation of fluorescent substances. Sensory evaluation demonstrated that microwave treatment, particularly at 400 W, 40 °C, and 3 min, significantly improved colour, clarity, and mouthfeel while reducing astringency and bitterness. In conclusion, microwave treatment effectively modifies the sensory characteristics of wine, offering a viable technological approach to accelerate wine ageing and supporting its potential application in winemaking. Full article

This study comparatively assessed the quality of organically and commercially produced turkey meat roasted to internal temperatures of 72 ± 2 °C, 80 ± 2 °C, and 88 ± 2 °C. The evaluation encompassed physical characteristics (pH, WHC, and colour), nutritional value (protein, ash, dry matter, fat and fatty acid profile and caloric value), and sensory characteristics. Thermal processing caused significant differences in the properties of the meat depending on the production system. After thermal processing, organic meat had a more favourable lipid profile (higher MUFA, PUFA and n-3 PUFA content and lower SFA content) compared to conventional meat, which indicates its potential nutritional advantage. The most favourable technological and sensory parameters, in this system, were obtained at an internal temperature of 80 ± 2 °C, while an increase to 88 ± 2 °C resulted in a deterioration in tenderness and juiciness. In commercially farmed meat, the best tenderness was found at 72 ± 2 °C and the highest aroma and flavour ratings at 80 ± 2 °C. The use of a temperature of 88 ± 2 °C led to an increase in cutting force, greater loss and reduced sensory quality. The results indicate the validity of differentiating the heat treatment parameters depending on the origin of the raw material. Full article

Coloured and variegated leaves are common in shade-tolerant ornamentals. However, it remains unclear whether their photosynthetic performance is determined mainly by pigment abundance or by the organisation of chloroplasts and thylakoids. We tested this in three Epipremnum aureum phenotypes (‘Neon’, ‘Golden’ and ‘Jade’) that share a genetic background but contrast in leaf colour, chloroplast density and thylakoid membrane abundance. Plants were grown in a greenhouse and assessed by hyperspectral and thermal imaging, infrared gas exchange analysis, chlorophyll a fluorescence measurements, and structural, ultrastructural and biochemical analyses. Traits were integrated by principal component analysis, with the quantum yield of CO₂ assimilation per absorbed photon (αCO_2,abs) as the response variable. ‘Neon’ leaves had high specific leaf area and approximately 55% lower maximum Rubisco carboxylation (Vc_MAX) and electron transport capacity (J_MAX) than ‘Jade’, as well as reduced chloroplast and thylakoid abundance and warmer canopies, despite carotenoid enrichment. JIP-test parameters and fluorescence light–response curves showed high absorption and dissipation per PSII reaction centre, elevated excitation pressure, modest non-photochemical quenching (NPQ), low αCO_2,abs, small carbohydrate pools and low intrinsic water-use efficiency. ‘Jade’ leaves developed thick mesophyll with dense chloroplast populations, extensive thylakoid networks, highest NPQ, cool canopies and large carbohydrate reserves, whereas ‘Golden’ leaves combined thin laminae and intermediate chloroplast–thylakoid organisation with early light saturation of CO₂ assimilation and the highest intrinsic water-use efficiency. Principal component analysis revealed a structural axis of chloroplast and thylakoid organisation that better predicted αCO_2,abs, net carbon gain and canopy temperature than pigment abundance. In variegated E. aureum, ‘photon economy’ is therefore governed primarily by chloroplast and thylakoid membrane organisation and abundance rather than by carotenoid accumulation. Full article

Escalating climate change and the increasing frequency of weather extremes pose a threat to the resilience of urban environments and human health, highlighting the urgent need for implementing energy-efficient interventions and reducing building cooling loads. This study investigates the passive building envelope retrofit technologies of external shading, electrochromic windows, and thermochromic windows through a multi-criteria evaluation analysis based on energy savings, economic performance, and indoor thermal comfort improvement. Thermochromic windows are discerned by a mean colour transition temperature of 34 °C and operate throughout the entire year, while electrochromic windows are activated only during cooling periods. Both technologies present total solar transmittance indices of 72.6% and 8.4% in the bleached and tinted state, respectively. External shading devices are either static or movable, applied with an inclination angle, and are either standalone interventions or combined with chromogenic glazing. Eight retrofit scenarios are investigated for a single-story, fully electrified residential building in Athens, Greece. The building features south- and east-oriented windows, which is an appropriate case to assess the effectiveness of these passive envelope cooling technologies in regulating solar heat gains. Thermal comfort is assessed using Fanger’s PMV (predicted mean vote) and PPD (Predicted Percentage of Dissatisfied) indices. The combination of electrochromic windows and movable external shading yields the highest annual electricity savings at 22.2% and reduces the PPD by 15.8%. Local static shading, on the other hand, ranks as the optimal retrofit solution in terms of economic performance, with a life-cycle cost of €6378, a 9.3% improvement in thermal comfort, and a corresponding reduction of 626 thermal discomfort hours. While the proposed multi-criteria framework can be applied to other buildings and climates, the quantitative results reported here are linked to the specific case examined: a residential building with south- and east-facing glazing in Athens, Greece, representing Mediterranean climatic conditions. Full article

Light is a critical regulator of circadian physiology, yet its delivery in intensive care units (ICUs) is primarily determined by architectural features and clinical workflows rather than by biological timing. This multicentre study (34 ICUs across nine hospitals) investigated bedside light exposure (illuminance and correlated colour temperature [CCT]) in neonatal (NICU), pediatric (PICU), and adult ICUs under routine operational conditions. Measurements were performed at the patient’s eye level during morning, afternoon, and evening/night periods, with ceiling luminaires switched on and off, and stratified by window proximity. Extreme operational heterogeneity was observed, with median morning bedside illuminance spanning more than a tenfold range across centres, and most ICUs failing to reach either the biologically referenced daytime level of ≥200 lux or the EN 12464-1 bedside task reference level of 500 lux. Artificial lighting increased illuminance but did not consistently mitigate spatial inequities related to window proximity. Spectral characteristics varied markedly at the same time. The use of artificial lighting frequently altered CCT, often reducing it by more than 1500 K, thereby overriding natural daylight cues and shifting the spectral environment toward an earlier circadian phase. These findings highlight the need to treat ICU lighting as a designable, population-sensitive environmental exposure, integrating architectural layout, operational practice, and temporal intent to support both clinical care and circadian health. Full article

Climate change influences the agronomic behaviour of fruit trees. It is necessary to determine which cultivars adapt best to conditions in which water supplies are becoming increasingly scarce. This study analyses different phenological, morphological, physiological, agronomic and productive parameters to evaluate water stress tolerance in six late-blooming almond cultivars widely grown in Spain (‘Ferragnès’, ’Francolí’, ‘Masbovera’, ‘Glorieta’, ’Guara’ and ‘Lauranne’). Two different plots were analysed: one under regulated deficit irrigation, at Les Borges Blanques, Lleida, with a water deficit (146.2 mm/year) and the other under rainfed conditions, at Mas Bové, Constantí, Tarragona, with a water deficit (284.5 mm/year). Parameters, including an increase in canopy volume, leaf-to-air thermal gradient, and slope between leaf water potential and level of leaf saturation, have proven to be good indicators of resistance to water stress. Yield variation and leaf temperature variation between rainfed and irrigated conditions also perform quite well. An assessment of leaf chlorophyll content, measured using SPAD-502, suggested the presence of a collateral effect resulting from the opacity of the biomass, as well as to chlorophyll-related cuticular colouring. Finally, under the experimental conditions, ‘Guara’ and ‘Masbovera’ proved the most resistant cultivars; ‘Glorieta’ and ‘Francolí’ exhibited an intermediate level, and ‘Lauranne’ and ‘Ferragnès’ were the least resistant cultivars. Full article

Coated tofu is prone to spoilage and degradation during processing, storage, and transportation. As the material basis for gel of coated tofu, proteins determine coated tofu’s unique qualities, such as its colour, flavour, and texture. This study aimed to investigate the changes in the quality of coated tofu and the physicochemical properties of its proteins during cold storage (4 °C and 10 °C, 14 days), as well as the intrinsic correlations between these variables. Quality deterioration and protein structural changes were significantly slower at 4 °C than at 10 °C, with lower temperature effectively delaying quality loss. The results indicated that as storage time increased, the freshness of coated tofu declined, its textural properties significantly deteriorated, and the protein gel network structure became impaired. Meanwhile, the proteins underwent significant oxidative denaturation, characterized by a decrease in the free thiol group content and an increase in surface hydrophobicity. The tertiary structure exhibited unfolding and disruption, while the secondary structure transitioned from an ordered to a disordered state. Specifically, the contents of α-helixes and β-sheets decreased significantly, reaching 34.96% and 8.68%, respectively, after 14 days of storage at 4 °C. In contrast, the contents of β-turns and random coils increased to 30.11% and 26.25%, respectively, under the same storage conditions. The subunit bands of the 11S and 7S proteins gradually weakened, and the protein structure tended to loosen. Correlation analysis revealed that the oxidative denaturation, structural depolymerization, and reaggregation of proteins were highly significantly correlated with the textural breakdown and colour deterioration of coated tofu, which together contributed to the quality degradation of coated tofu during cold storage. The findings of this study provide fundamental data and technical support for the development of cold storage methods for coated tofu. Full article

This study investigated the effect of fermentation time (24 and 48 h) on the pH, titratable acidity (TTA), phytochemicals, antioxidants, phenolic compounds, colour, functional, pasting, and thermal properties of flours from selected legumes (mung beans, haricot beans, butter beans, and black beans). The pH dropped significantly (p ≤ 0.05) after 48 h (6.61–4.91) of fermentation, with a corresponding increase in TTA, which ranged from 0.3 to 1.28 g lactic acid/100 g sample. Colour analysis showed that fermentation caused a decrease in L* values (2.97–23.86% reduction), with the highest reduction observed in black bean flour (23.86% at 24 h), along with an increase in the browning index. The total phenolic content increased significantly (p ≤ 0.05) in all the samples, with the most pronounced increase observed in mung bean 24 h (6.85 mg GAE/g). Similarly, the values for total flavonoid increased from 2.26 to 6.48 mg QE/g, and antioxidant activities such as DPPH ranged from 45.04 to 74.51%, FRAP from 1.65 to 8.03 Mm TE/g, and ABTS from 60.86 to 90.01%. Ultra-high performance liquid chromatography–photodiode array quantification of the targeted phenolic compounds showed a significant increase, with the highest notable increase for trans-ferulic acid in mung bean (330% after 48 h). Water absorption capacity generally showed an increase, whereas bulk density ranged from 0.55 to 0.91 g/cm³ and decreased in all legumes. There were differences in the pasting properties of the selected legumes. The peak time of unfermented butter bean was 33.08 min and remained constant at 33.15 min at 24 and 48 h of fermentation. Thermal analysis indicated the alteration of gelatinization parameters, with a decrease in peak temperature, whereas higher gelatinization enthalpy was observed. Findings from this study show that fermentation with the starter cultures can significantly improve the bioactive compound and functional properties of legume flours and thus act as potential ingredients in functional food development. Full article

Pasta is a staple food and is a typical commodity worldwide. However, some people with celiac disease or gluten intolerance cannot consume pasta formulated with wheat flour. This work aimed to develop and characterise pasta samples made from wheat and buckwheat flours fortified with carrot powder at concentrations of 5% and 10%. The developed pasta samples were analysed for drying and hydration characteristics, for cooking properties, pasting properties, colour, texture, and sensory attributes. The results showed that the wheat-based pastas had better hydration and cooking properties, and that the gluten-free pastas were less cohesive. Concerning hardness, the addition of carrot powder produced opposite results for the wheat- and the buckwheat-based pastas. The gluten-free samples had higher pasting temperatures and peak viscosities and were also darker; however, lightness, redness, and yellowness increased with the addition of carrot powder. The gluten-free pastas were richer in terms of nutrients, carotenoids, and phenolic compounds due to the presence of buckwheat instead of wheat flour, and the increased addition of carrot powder also contributed to the increase in these nutrients. The sensory evaluation revealed that judges preferred the wheat-based pasta samples over the buckwheat counterparts, and the addition of carrot powder at the highest percentage significantly improved the sensorial assessment. In conclusion, the pasta samples formulated have high nutritional importance, and sensorial acceptance was increased with the addition of carrot powder. Full article

The aim of the study was to investigate the effect of hydrothermal treatment (different steaming process) conditions, specifically temperature, pressure, and steaming time on selected physical properties of beech wood (Fagus sylvatica L.), such as moisture content, density, colour, and longitudinal contraction. The research was conducted using two steaming modes: pressure steaming process (108 °C, 181 kPa, 7 h) and atmospheric steaming process (80 °C, 101 kPa, 15 h). The results showed that pressure steaming caused a more significant decrease in moisture content (by 16.9%) compared to atmospheric steaming (by 8.0%) and a smaller variation in values, which is favourable for subsequent drying. The differences in density after steaming were not statistically significant. On the contrary, longitudinal shortening was significantly greater with pressure steaming, which may indicate the release of tension reaction wood. The colour change was similar in both modes; lightness (L*) decreased and the wood acquired a redder hue without a significant effect of steaming conditions on the overall colour differentiation (ΔE). The results confirm that steaming temperature and pressure have a significant effect on the moisture change and longitudinal contraction of beech wood, while density and colour change remain relatively stable. The length of the steaming process has a major effect on the colour change of the wood. Full article

The effect of active packaging on maintaining the quality of cherry tomatoes and kale during storage was investigated. The active packaging consisted of kraft paper sheets coated with thymol/eugenol (50:50) encapsulated in β-cyclodextrin. Cherry tomatoes were stored at 10, 15, and 22 °C for 15, 14, and 8 days, respectively, while kale was stored at 2, 8, 15, and 22 °C for 21, 16, 9, and 7 days. Physicochemical (pH, total soluble solids, titratable acidity, colour, and firmness), microbiological (mesophilic, psychrophilic, enterobacteria, moulds, and yeasts) and pigment/bioactive/nutritional (chlorophylls, carotenoids, total phenolic content, vitamin C, and total antioxidant capacity) characteristics were analysed. Active packaging significantly reduced microbial growth, particularly enterobacteria and moulds, in cherry tomatoes and psychrophiles and moulds in kale, without negatively affecting the physicochemical quality. The microbial kinetics were successfully described using the Baranyi–Ratkowsky predictive model, which quantified the effects of temperature and active packaging on microbial growth parameters. This modelling approach revealed that active packaging increased the minimum growth temperature and reduced the specific growth rate of key microbial groups, confirming its inhibitory action under different storage conditions. The use of active packaging slowed colour degradation in kale by reducing chlorophyll loss up to 50% at 22 °C and maintained tomato firmness and colour during storage. Furthermore, a strong correlation (R² = 0.87) between colour index and carotenoid content was found, enabling the non-destructive prediction of ripening in tomatoes. Overall, active packaging enhanced microbial stability, delayed visual deterioration, and sustainably extended the shelf life and post-harvest quality of perishable products, offering a promising alternative to conventional preservation methods. Full article