Search Results (1,019)

In this study, the effect of five natural plant modifiers, i.e., clove, ginger, dandelion, stinging nettle, and quinoa, on the surface and optical properties of epoxy coatings based on the Epidian^® 5/IDA system was evaluated. The modifiers were introduced in a constant amount of 3.0 wt.% of the total sample mass. The samples were subjected to short-term UV-Vis (460 nm), UVB (320 nm), and UVC (254 nm) exposure, followed by measurements of Ra/Rz roughness, CIELAB colour, gloss, Raman spectra, reflectance, light transmittance, and moisture resistance under condensation conditions. The addition of modifiers increased the roughness compared with the reference coating, particularly in the case of the coating containing dandelion (R_a = 2.110 µm; R_z = 8.463 µm in the series without UV exposure), whereas UV exposure in many cases led to partial smoothing of the surface. The greatest colour change was observed after UVB irradiation for the coating containing quinoa (ΔE* = 7.10), with a simultaneous increase in the yellow component Δb*. The 60° gloss was strongly dependent on the type of additive; the lowest values were recorded for dandelion, and relatively higher values for clove and ginger. Raman spectra confirmed the presence of bands typical of plant components, while reflectance revealed the greatest sensitivity of changes in the UV range. The condensation test after 500 h showed that plant modifiers may deteriorate the barrier properties of the coatings, particularly in the case of nettle, dandelion, and clove. The results indicate that plant modifiers are promising additives for modifying the properties of epoxy coatings, but their application requires control of particle size, dispersion, and compatibility with the matrix. Full article

Bacterial fluorescence generated by endogenous fluorophores may provide an optical approach for monitoring microbial fluorescence responses. The aim of this study was to analyse temporal changes in the Hue parameter, defined as an image-derived component of the HSB colour space representing the dominant colour tone, and to characterize strain-associated fluorescence response profiles under 405 nm violet-light excitation. A total of 28 reference bacterial strains were examined. Each strain was inoculated at eight distinct locations on a separate BHI agar plate, yielding eight colonies per strain. At 24, 48, 72, 96, and 168 h of incubation, the same colonies were repeatedly exposed for 45 s to a 405 nm continuous-wave diode laser operating at 200 mW and imaged in a completely darkened room using an iPhone 14, a yellow emission filter, and fixed acquisition geometry. The JPEG images were converted to the HSB colour space in ImageJ software (version 1.54), and background-corrected Hue values were calculated for each colony as ΔHue = Hmean − Hmean_BG using the corresponding colony and agar-background regions of interest. A complementary qualitative visual assessment was performed, and aligned rank transform ANOVA was used to evaluate the effects of bacterial strain, incubation time, and their interaction. ΔHue values differed significantly between strains and across incubation time points, with significant strain × time interactions observed in both rod-shaped and coccal bacteria (all p < 0.001). Exploratory planned contrasts also showed differences between the predefined Gram-staining groups (p = 0.0002) and between rod-shaped and coccal bacteria (p < 0.0001); however, these comparisons do not establish independent effects of Gram status or cellular morphology. The recorded fluorescence signal was generally weak, although visible temporal changes occurred in selected strains, including Staphylococcus aureus ATCC 6538P and Proteus mirabilis PCM 543. Overlap between ΔHue distributions limited separation of some strains. Background-corrected Hue analysis enabled exploratory within-dataset monitoring of temporal fluorescence colour changes under the applied in vitro imaging protocol. However, the overlap between ΔHue distributions and the technical limitations of the imaging system preclude the use of ΔHue as a standalone bacterial identification or diagnostic parameter. Full article

We evaluated moderate cluster-zone warming in field-grown Monastrell grafted onto 110R and 140Ru over two seasons (2020–2021) in a semi-arid vineyard in south-eastern Spain. From pea-size to harvest, an open warming system increased cluster-zone air temperature by 1.15 °C on average. Warming increased cluster-zone mean and maximum temperatures, but berry temperature responses depended on year and rootstock because berry–air temperature differences and also time above thresholds changed. Berry weight increased in harvest in both years, and technological ripening advanced, with higher total soluble solids and maturity index, especially during ripening. Acid composition responded differently between rootstocks: under warming, 140Ru maintained higher malic acid and lower tartaric acid than 110R, resulting in a lower tartaric/malic ratio. Phenolic and colour responses were clearest at mid-ripening. Warming reduced must total phenolic index (TPI), skin-related phenolics, anthocyanins, and must colour more strongly in 140Ru, while 110R retained a more stable phenolic and colour profile. Exposure–response analyses showed that time in the 25–35 °C range and berry thermal time were more closely related to technological and phenolic variation than time above 35 °C. These results suggest that, under the warming conditions imposed in this study, 110R offered a better compromise than 140Ru between ripening advancement and the preservation of phenolic and colour-related traits. Full article

This experiment aimed to investigate the effects of different lighting cycles on the growth performance, serum biochemical indices, slaughter performance, skeletal development, and meat quality of yellow-feathered broiler chickens. A total of 256 10-day-old Liangfenghua yellow-feathered male broilers were randomly assigned to four groups, each with 8 replicates, and each replicate contained 8 chickens. The four lighting cycles used were 18L:6D, 20L:4D, 22L:2D, and 23L:1D (hours of light:dark), and the chickens were fed until 63 days of age. The results indicate that with increasing light exposure duration, the average daily gain and live weight of yellow-feather broilers from 10 to 21 days of age (p = 0.07), the average daily feed intake from 42 to 63 days of age (p < 0.01), as well as the average daily feed intake, daily gain, and feed-to-gain ratio from 1 to 63 days of age (p < 0.05), all showed linear changes. The live weight, daily gain, and feed-to-gain ratio from 42 to 63 days of age exhibited both linear and quadratic variations (p < 0.01). The 22L:2D group achieved the highest live weight and daily gain at 63 days, with the lowest feed-to-gain ratio. Serum glucose levels displayed quadratic variation, while phosphorus levels showed both linear and quadratic changes; the 22L:2D group had the lowest serum glucose and the highest phosphorus levels. The semi-eviscerated rate and the bursa of Fabricius index varied linearly, whereas the leg muscle rate showed quadratic variation. The 20L:4D group had the highest total eviscerated rate, breast muscle rate, and leg muscle rate (p < 0.05), with the lowest Fabricius and thymus indices. The length, width, and volume of the femur and tibia, as well as the tibia bone volume and tissue volume, all changed linearly (p < 0.05). The tibia bone volume fraction exhibited both linear and quadratic changes, with the 18L:6D group showing the highest femur length, width, tibia bone volume, tissue volume, and bone volume fraction. Light exposure significantly affected meat pH, colour, shear force, drip loss, and cooking loss. The crude protein content in the breast muscle showed quadratic variation, while ash and cysteine contents displayed both linear and quadratic changes. The 22L:2D group had the highest crude protein content, pH at 24 h, shear force, and drip loss, but the lowest amino acid and ash contents (p < 0.05). Additionally, there were significant differences in the flavour of the breast muscle under different light cycles. In summary, the photoperiod significantly affects the production performance, skeletal development, meat quality, and flavor of yellow-feathered broilers. The 22L:2D photoperiod yielded the best outcomes in promoting growth, improving feed efficiency, and enhancing meat quality; however, it may adversely affect skeletal development and structural integrity, and caution should be exercised for long-term rearing. Full article

Climate change poses an increasing threat to viticulture sustainability, particularly in traditional wine regions, where varietal regulations restrict the adoption of new cultivars. Elevated temperature and water deficit may alter anthocyanin accumulation and the broader phenolic profile of ripening berries, directly affecting wine colour, structure, and quality. In this context, exploring intra-varietal diversity may help to identify clones with a favourable phenolic profile that could contribute to adaptation strategies within existing varietal regulations. We report the first comprehensive monomeric phenolic profiling, by UHPLC-QqQ-MS/MS, of grape berries from eleven Vitis vinifera L. ‘Tempranillo Tinto’ clones (two seasons) and seven ‘Graciano’ clones (three seasons), from old vineyards in La Rioja (Spain). Six phenolic classes were quantified: hydroxycinnamic acids, hydroxybenzoic acids, flavonols, flavanols, stilbenes, and anthocyanins. Multivariate analysis of variance, linear mixed-effects models, principal component analysis, and hierarchical cluster analysis were used to characterize clonal diversity. Significant clone effects were detected for all six phenolic classes in ‘Graciano’ and four in ‘Tempranillo Tinto’. In ‘Graciano’, clone GR_1250 was distinguished by elevated flavonol and anthocyanin levels, whereas GR_1265 showed the highest flavanol and hydroxybenzoic acid content. In ‘Tempranillo Tinto’, clone TT_1041 stood out for its higher flavanol and hydroxybenzoic acid concentrations, whereas TT_767 had elevated anthocyanin levels. Two to four distinct phenotypic clusters were identified within each variety. These results confirm substantial intra-varietal phenolic diversity in both cultivars and identify clonal selections with differential phenolic profiles that may be useful for quality-oriented clonal selection, particularly when integrated with agronomic, phenological, sanitary and wine-level information. Full article

Previous characterisation of historic blue bricks (qingzhuan) from Beijing identified compositional and physical differences across periods, but their effect on early-stage freeze–thaw behaviour was untested. An adapted laboratory wetting–freezing–thawing procedure was applied to four Ming-attributed and four Qing-attributed Great Wall bricks from the Miyun section as the primary cohort, with Lingyue Temple and Guanyin Chanlin bricks as supporting cases. The 10-cycle endpoint is below the 15 cycles GB/T 2542-2012 prescribes for a frost-resistance rating, so the results index early-stage damage sensitivity, not freeze–thaw durability. Dry mass loss, colour difference (ΔE*_ab), gloss change and visible damage were evaluated. The lower-density, higher-absorption (Ming-attributed) group lost 1.22 ± 0.84% of its dry mass versus 0.37 ± 0.12% for the denser, lower-absorption (Qing-attributed) group, with complete rank separation that persists after normalising by estimated coupon surface area. At four bricks per group, the exact Mann–Whitney result (U = 16, p = 0.029) sits at the smallest attainable p-value, so the comparison is exploratory and hypothesis-generating and establishes no dynastic difference in frost resistance. Bulk properties predicted neither damage magnitude nor mode: a low-mass-loss coupon fractured through, and the metrics ranked specimens differently. Conservation assessment should report material loss, structural integrity and surface preservation as separate endpoints, and match repair material by water absorption, pore structure and freeze–thaw behaviour rather than colour and composition alone. Full article

The rapid growth of avian genomic resources has created a field rich in genomic data but still in need of integrative synthesis. Here, we review evidence linking four colour-producing systems—melanin, carotenoids, psittacofulvins and structural colouration—to feather development and evolutionary change. Melanin output is shaped by the MC1R–ASIP–MITF regulatory axis, melanogenic enzymes and the local availability of substrates such as cysteine. Carotenoid colouration depends on dietary uptake, SCARB1-mediated transport, BCO2-regulated precursor availability and, in many red species, CYP2J19-mediated ketolation acting with BDH1L; however, CYP2J19-independent red routes demonstrate that similar colour phenotypes can evolve through different molecular solutions. Structural colours arise from feather nanostructures and may interact developmentally with pigment deposition, whereas psittacofulvins represent an independent pigment system in parrots. We also discuss sex-biased gene expression, feather-region specificity, environmental sensitivity and lineage-specific regulatory change. Overall, avian plumage colour evolution is shaped by conserved biochemical and developmental constraints, yet similar colour phenotypes can arise through different regulatory, metabolic or structural routes. Full article

Hyperspectral imagers (HSIs) enable the non-invasive, spectrally resolved quantification of pigments. HSIs have many environmental research applications, including the monitoring of threatened ecosystems like coral reefs and evaluating the success of coral restoration efforts. However, the high cost of commercial HSIs has restricted wider uptake of the technology. Here, we tested the efficacy of a low-cost (~USD 200) and open-source HSI device (400–1000 nm, spectral resolution of ~2 nm Full width at half maximum (FWHM)) in coral bleaching research. Specifically, we evaluated its ability to quantify the concentration of key photosynthetic pigments (chlorophyll a, chlorophyll c2, diadinoxanthin, peridinin, and total pigment content) by comparing it against a research-grade (~USD 70,000) commercial hyperspectral camera using coral fragments subjected to varying levels of thermal stress. The low-cost HSI acquired coral reflectance spectra that were similar to those acquired by the commercial hyperspectral camera, with a mean spectral angle of 11.38 ± 3.82°. However, the low-cost device was unable to resolve differences in spectral magnitude to the same accuracy as the commercial HSI and did not detect differences among coral fragments at different levels of thermal stress. Thus, the current HSI device prototype is better suited for classification and diagnostic applications in which spectral shape is of greater importance than spectral magnitude. Partial least squares regression models built from the reflectance spectra of each HSI instrument showed very similar yet moderate performance when predicting key coral pigments (commercial HSI mean Root Mean Square Error of Prediction (%RMSEP) = 22.8%, low-cost HSI = 22.12%). While the current design of the low-cost HSI device has limitations, it shows potential for coral research at a fraction of the cost of commercial alternatives. The continued development of low-cost HSI platforms is accelerating rapidly across a variety of fields in environmental research, and improved designs have the potential to enhance coral reef monitoring and restoration efforts globally. Full article

The diverse colour range of tropical woods is a highly valued commercial feature for specialized interior applications. This study evaluates the long-term indoor colour changes in 98 tropical wood species from Goa (India), Mozambique, and East Timor, stored in a xylarium for 45–50 years. Using the CIEL*a*b* system, surface colour changes ΔL*, Δa*, Δb* and ΔE were quantified by comparing unexposed reference surfaces, obtained through sanding, with the long-term exposed surfaces. Results showed that darkening occurred in 96% of the species, though visual assessments identified colour differences in only 58% of the samples. Pteleopsis myrtifolia (Lawson) Engl. and Diels and Bombax malabaricum DC. (both light yellowish-brown) exhibited almost no change, while Cedrela odorata (light pinkish-brown) and Pterocarpus antunesii (moderate orange-brown) showed slight lightening. The initial wood colour was not a significant predictor of the magnitude of chromatic change. Total colour difference (ΔE) was primarily driven by reductions in lightness (ΔL*), followed by hue change (Δh*). The chromatic components contributing to ΔE differed according to the initial lightness class: in lighter woods (L* > 50), redness change (Δa*) showed the strongest chromatic contribution to ΔE, whereas in darker woods (L* ≤ 50), yellowness change (Δb*) was the dominant chromatic contribution. With a mean total ΔE of only 5.76, the overall wood chromatic identity of most species was maintained over time. These findings indicate that indoor ageing of tropical woods is mainly characterized by progressive darkening rather than by drastic chromatic shifts, supporting their long-term aesthetic suitability for premium interior applications over several decades. Full article

This study investigated the effects of drying methods, namely freeze-drying and vacuum-drying, and heating plate temperature (20 °C, 40 °C, and 60 °C) on the drying kinetics, specific energy consumption, proximate chemical composition, colour, peroxide value, pH and cutting force of beef eye of round muscle, pork loin, and chicken fillet. Drying time ranged from 360 min for pork loin freeze-dried at 60 °C to 1050 min for beef eye of round muscle vacuum-dried at 20 °C, and freeze-drying was generally faster than vacuum-drying at the corresponding temperature settings. Among the tested models, the logarithmic model provided the best fit to changes in the moisture ratio, with R² values of 0.9972–0.9997 and RMSE values of 0.0053–0.0151. Increasing the drying temperature reduced the specific electrical energy consumption per kilogram of dried product in both drying methods, which was associated with shorter drying times at higher temperatures. Fat and protein contents did not differ significantly in products dried at 20 °C and 40 °C, but decreased at 60 °C, reaching 8.85–12.26 g/100 g d.m. and 76.16–79.86 g/100 g d.m., respectively. Drying also affected lipid oxidation and pH. At 20 °C and 40 °C, changes in peroxide value were moderate, whereas at 60 °C lipid oxidation markedly increased, especially in chicken meat and vacuum-dried samples. Both drying methods reduced pH compared with the raw material, with the greatest decrease observed at 60 °C, particularly after vacuum-drying. The highest L* value among dried samples was recorded for chicken fillet freeze-dried at 20 °C (85.44), whereas the lowest was observed on the surface of beef eye of round muscle vacuum-dried at 60 °C (41.98). Increasing temperature decreased lightness and redness but increased yellowness and cutting force. Cutting force ranged from 35.7 N for chicken fillet freeze-dried at 20 °C and cut across the fibres to 231.4 N for beef eye of round muscle vacuum-dried at 60 °C and cut along the fibres. These results indicate that the drying method and temperature strongly affect the quality attributes of dried meat and should be selected according to the desired product characteristics. Future studies should focus on the optimisation of drying parameters for specific meat types and include a broader quality assessment, particularly microbiological safety and sensory properties. Full article

The effects of asparaginase treatment and conditions of its use (enzyme dose and dough resting time) on the formation of heat-induced contaminants, namely, acrylamide (ACR) and 5-hydroxymethylfurfural (HMF), were investigated in wholemeal wheat biscuits. In addition, potential impacts on sensory-related quality attributes were assessed through instrumental analysis of colour, texture, and volatile organic compounds (VOCs). Three levels of asparaginase addition (100, 300, and 500 ASNU kg⁻¹ flour) were tested and compared with an untreated control, with and without the application of a 15 min dough resting step. Results confirmed the effectiveness of asparaginase in reducing ACR levels in the final biscuits, showing a dose-dependent response with reductions of up to 68% at 500 ASNU kg⁻¹ flour. A dough resting step tend to further lower ACR content. In contrast, asparaginase treatment did not exert a consistent effect on HMF formation, whereas dough resting tended to decrease it. Moreover, asparaginase addition at the highest dose reduced the level of several Maillard reaction-derived VOCs by approximately 30%. Overall, asparaginase treatment markedly reduced ACR formation while causing changes in some odour-active compounds in biscuits. Further sensory evaluation will be necessary to determine whether these changes are perceptible and may influence consumer acceptance. Full article

This study assesses the durability of self-cleaning and antimicrobial activities of dishcloths made of 100% cotton woven fabric modified with TiO₂ nanoparticles (NPs) and zinc pyrithione particles (ZnPt). The self-cleaning properties were measured as the ability to decompose staining particles via photocatalytic action under UV/VIS light irradiation and confirmed by colour measurements (K/S values, colour differences, and colour changes ΔL*, Δa*, Δb*). The SEM micrographs confirmed the long-term durability of the modification process, and ICP-OES analysis confirmed the presence of Ti and Zn elements on and within the fabric. The amounts of TiO₂ and ZnPt decreased by 2.2–2.5 times after the first 5 washings and by 2.1–1.2 times after the subsequent 45 washings. Antimicrobial activity was tested against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 11229 and Candida albicans ATCC 10231. The results indicate that the material maintains excellent self-cleaning properties and good antimicrobial activity for up to 50 washings; however, activity against E. coli remains weak after 30 and 50 washings. Full article

Background: Tooth bleaching is a conservative aesthetic treatment that may influence tooth translucency, an optical property relevant to biomimetic dentistry. The purpose of this study is to evaluate changes in tooth translucency after three bleaching protocols, while preliminarily testing an objective, image-based, and spatially resolved method. Materials and Methods: A retrospective analysis used data from a previously published randomised clinical trial comparing three bleaching systems: in-office 6% hydrogen peroxide paint-on varnish; at-home 6% hydrogen peroxide prefilled tray; and at-home 16% carbamide peroxide custom tray. Spectrophotometric images of maxillary central incisors and canines were retrieved at different stages, and their translucency maps were processed with ImageJ to quantify the percentage of translucent area, histogram-derived grey intensity and RGB-blue channel metrics. Statistical tests were performed appropriately (α = 0.05). Results: All bleaching protocols produced significant post-treatment increases in translucency-related parameters (p < 0.05), although the in-office protocol showed smaller changes than the at-home techniques (p < 0.05). At six months, the translucent area remained significantly higher in most conditions, whereas histogram-derived metrics showed no significant changes. Correlations between translucency-related parameters and colour/whiteness differences were mostly negligible to weak. Conclusions: The preliminary image-based assessment detected significant and technique-dependent changes in translucency-related parameters following bleaching, with a weak linear association between these changes and colour outcomes. Full article

Monitoring ultraviolet (UV) radiation dose distribution is crucial in many fields, like medicine and materials science, but traditional point-of-care methods limit the ability to fully assess the spatial extent of the irradiated surface. This paper presents the characterisation of a two-dimensional (2D) dosimetry system based on Pluronic F-127 hydrogel matrix doped with 2,3,5-triphenyltetrazolium chloride (TTC) with respect to exposition to UVA radiation. The hydrogel matrix (25% w/w) provides both high transparency and mechanical stability, while TTC (0.1% w/w) functions as a colour precursor that undergoes irreversible reduction to form water-insoluble red formazan upon UVA exposure. The insolubility of TTC formazan ensures that the resulting colour changes remain spatially stable within the dosimeter. The study included sample preparation in flat PMMA containers and analysis of the effect of radiation field uniformity in a UVP CL-1000 exposure chamber. It was supported by application of Kodak X-Omat 100 NIF UV Film dosimetry. The actual dose distribution in the chamber was shown to be significantly heterogeneous (CV coefficient of variation of approximately 18%), which emphasises the need for 2D dosimeters for precise validation of irradiation devices. The use of flatbed scanning and dedicated image analysis software allowed obtaining precise 2D dose distribution maps. The dosimeter was characterised in the dose range of 0–5000 mJ/cm², showing a reproducible response (R² = 0.9967). A resolution test was conducted to assess the precision of geometric representation. In the final stage of the study, the suitability of the developed dosimetry system was verified under conditions simulating heterogeneous UV radiation dose distribution using patterns printed with Computer-to-Film (CtF) technology. The results showed that optical effects in printed films significantly affect UV transmission, limiting accurate dose recording for black coverage above approximately 40–50%. The results obtained confirm that the TTC-Pluronic F-127 system is an effective, simple and low-cost tool for 2D monitoring of UVA radiation, with potential applications in cosmetology, dermatology, and material ageing tests. Full article

This study examined the physicochemical, microbiological, textural, organic acid, colour, and sensory aspects of cabbage pickles made with fermented dairy by-products as a brine medium. Yoghurt whey, whey, kefir whey, and buttermilk were used as brine media and compared with vinegar. Brine samples showed substantial changes in pH, Brix, colour, and rheology (p < 0.05). Yoghurt whey-based samples had the lowest brine pH (2.87) and Brix (10.04%), while buttermilk samples had the highest pH (3.26) and Brix (10.83%). Vinegar-based brine showed higher a* and b* values, whereas yoghurt whey-based brine had the highest L*. Yoghurt whey-based samples had lower consistency and a lower viscosity index. Pickle samples made with different brine types showed significant differences in physicochemical, microbiological, textural, and organic acid properties (p < 0.05). Pickle samples made with vinegar had the lowest pH (2.99), while samples made with buttermilk had the highest (3.31). Vinegar-based pickles had the highest dry matter (5.27%) and drained weight (64.15%). Yoghurt whey-based samples had the highest counts of Lactobacillus spp. (6.38 log CFU/g) and Lactococcus/Streptococcus (6.81 log CFU/g), while vinegar-based samples had the highest counts of acetic acid bacteria and total aerobic mesophilic bacteria. However, kefir whey-based samples had the highest yeast count (5.72 log CFU/g). The textural analysis showed that yoghurt whey-based samples had the highest hardness (471.72 N) and springiness, whereas buttermilk-based samples had higher adhesiveness and cohesiveness. Whey-based samples had the highest gumminess and chewiness. Yoghurt whey-based samples had the highest levels of lactic acid (14,569.39 mg/L) and citric acid, whereas vinegar-based samples had the highest levels of acetic acid (63,795.64 mg/L) and propionic acid. Kefir whey-based samples had the highest butyric acid content. Yoghurt whey-based pickles were the most popular with panellists, followed by whey and vinegar-based pickles. Buttermilk-based samples scored lowest in sensory rating. Finally, fermented dairy by-products can be used as a functional brine medium for cabbage pickle. Yoghurt whey has shown promise in improving microbiological quality, textural characteristics, and sensory acceptability. Using dairy industry by-products in pickle making is an innovative way to produce sustainable food and add value to by-products. Full article