Search Results (314)

The impact of five different nets—conventional black, grey, white, and photoselective red and yellow—on the performance of “Gala Redlum” apples was evaluated over a five-year period (2020–2024) and compared to an uncovered control. The cumulative production over this period, ranked from highest to lowest, was as follows: white net (182.4 t/ha), grey net (178.5 t/ha), yellow net (175.8 t/ha), black net (175.5 t/ha), red net (169.5 t/ha), and uncovered control (138.8 t/ha). Vegetative growth results were inconsistent among the studied years. The cumulative photosynthetic rate (An) was slightly higher under the white net (57.9 µmol m⁻² s⁻¹). Fv/Fm values remained closest to optimal levels under the black and grey nets. Netting effectively protected fruits from elevated temperatures, particularly under the grey net, and reduced sunburn damage, with the grey, black, and yellow nets performing best in this regard. Overall profitability was increased by netting: the black net provided the highest cumulative income per hectare over a five-year period (EUR 72,315) alongside the second-lowest sunburn loss (0.69%), while the yellow net also showed strong economic performance (€64,742) with a moderate sunburn loss (1.26%) compared to the red net. Fruit dry matter and soluble solids content (SSC) were generally higher in the uncovered control, whereas °Hue values tended to be higher under the red and yellow nets. In summary, the black and yellow nets provided more balanced microclimatic conditions that enhanced tree performance, particularly under heat stress, leading to improved yield and profitability. However, the economic feasibility of each net type should be evaluated in relation to its installation and maintenance costs. Full article

Paulownia elongata wood is characterized by rapid mass gain, but its limited mechanical strength hinders engineering applications. This study aimed to determine the effect of thermal modification in a steam atmosphere (at temperatures of 180 °C and 190 °C for 12 or 6 h with 3 or 6 h of steam dosing) on wood’s selected physicochemical and aesthetic properties. Color changes (CIELAB), chemical composition (FTIR), density, and compressive strength parallel to the grain were evaluated. The results showed a clear darkening of the wood, a shift in hues towards red and yellow, and an increase in color saturation depending on the treatment parameters. FTIR spectroscopy confirmed a reduction in hydroxyl and carbonyl groups, indicating thermal degradation of hemicelluloses and extractives. Wood density remained relatively stable, despite observed mass losses and reduced swelling. The most significant increase in compressive strength, reaching 27%, was achieved after 6 h of modification at 180 °C with a concurrent 6 h steam dosing time. The obtained results confirm that thermal treatment can effectively improve the functional and visual properties of paulownia wood, favoring its broader application in the furniture and construction industries. Full article

With the increasing market demand for spinels of various colors, purple spinel—long regarded as a symbol of nobility—has attracted growing attention. In this study, pinkish-purple to purple spinels from the Mogok region of Myanmar were systematically examined using conventional gemological, spectroscopic, and chemical analytical techniques. Raman analysis reveals that these spinels commonly contain octahedral inclusions composed of calcite, dolomite, magnesite, and graphite. Chemically, the samples are primarily magnesia-alumina spinels. Color variation is influenced by trace elements: increasing Cr and V contents enhance the red hue, while higher Fe concentrations intensify the purple tone. UV–Vis spectra show that Cr³⁺ and V³⁺ jointly contribute to absorptions at 388 nm and 548 nm, with Fe²⁺ and Fe³⁺ responsible for the bands at 371 nm and 457 nm, respectively, together controlling the pink-to-purple color variation. Most samples display four Cr³⁺-related peaks near 700 nm; however, these are absent in deeply purple spinels. In contrast, light pink spinels show weaker absorption at 371 nm and 457 nm, attributed to Fe²⁺ and Fe³⁺. Fluorescence spectra confirm characteristic Cr³⁺ emission bands at 673 nm, 684 nm, 696 nm, 706 nm, and 716 nm, indicating a strong crystal field environment. Raman spectra have peaks mainly around 312 cm⁻¹, 406 cm⁻¹, 665 cm⁻¹, and 768 cm⁻¹. The peaks of the infrared spectrum mainly appear around 840 cm⁻¹, 729 cm⁻¹, 587 cm⁻¹, 545 cm⁻¹, and 473 cm⁻¹. Full article

Dietary bitter compounds such as caffeine have the potential to reduce backfat in pigs. However, the use of caffeine as a feed additive has restrictions in many countries. It was hypothesised that grape seed and gentian plant extracts (GG) could replace caffeine in feed due to their bitterness and antiadipogenic effects. The effect of caffeine (0.5 g/kg), GG (2 g/kg) alone or in combination with caffeine (BM) at increasing concentrations (0.5, 1, 1.5, or 2 g/kg) on feed efficiency, carcass, and meat quality was assessed in finishing pigs (Large White × Landrace). Growth performance and carcass traits were evaluated at a pen level (n = 14). Loins (longissimus thoracis) were removed from eight pig/treatment at the abattoir to assess drip loss, lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue angle (h°), pH, cook loss, and shear force. A linear increase (p < 0.05) in loin a*, b*, and C* values and a linear decrease (p < 0.05) in ADFI, ADG, backfat, dressing percentage, and HSCW were observed with increasing BM levels. At 1.5 g/kg, BM increased the loins a* (p < 0.05), b* (p < 0.05) and C* values (p < 0.05) compared to the control. Twenty-two proteins related to energy metabolism and myofibril assembly were identified to be upregulated (FDR < 0.05) in BM vs. control loins. In conclusion, GG could be used in combination with low doses of caffeine to modulate appetite and carcass leanness and improve pork colour. Full article

The colour evolution of malvidin-3-O-glucoside (Mv-3-O-glc) elicited by caffeic acid (CAF), (+)-catechin (CA), or syringic acid (SI) was spectrophotometrically monitored in model wine solution, modulating the malvidin-to-polyphenol molar ratio (1:1 to 1:20) and the pH (2.8–3.8). The spectral features provided the thermodynamic parameters Gibbs free energy (ΔG⁰) and equilibrium constant (K_eq), showing that the copigmentation extent is maximized at pH 3.6 and a higher molar ratio (1:20), and that copigments have different efficiency. In a long-term evolution (12 months), transient complexes evolved into different colour characteristics. Spectrophotometry and colorimetry (chroma C*, hue H*, and lightness L*) revealed the formation of stable pigments with peculiar orange-reddish colour when CAF was present; however, in the case of CA, an accentuated yellow tone was observed. SI showed minimum impact in the long-term evolution of Mv-3-O-glc. This study expands knowledge on oenological copigmentation, further exploring its potential implication in the colour of aged red wines. Full article

Bract coloration in ornamental plants is a complex trait governed by diverse pigments (chlorophylls, anthocyanins, betalains, and carotenoids), their biosynthetic pathways, and regulatory networks. While previous research has primarily focused on floral pigmentation, studies on bract coloration—particularly in species where bracts serve as the primary ornamental feature—have received less attention until recent advances. This review synthesizes current understanding of bract color diversity, pigment biochemistry, and molecular regulation in key species including Bougainvillea, Euphorbia pulcherrima, Anthurium andraeanum, Curcuma alismatifolia, and Zantedeschia hybrida. Anthocyanins predominantly contribute to red-to-purple hues, while betalains generate red, purple, or yellow coloration through differential accumulation of betacyanins and betaxanthins. Developmental color transitions are mediated by chlorophyll degradation and carotenoid dynamics. The spatiotemporal regulation of pigment accumulation involves coordinated interactions between key structural genes (CHS, DFR, ANS for anthocyanins; DODA, CYP76AD1 for betalains), transcription factors (MYB, bHLH, WRKY), and plant growth regulators (BAP, GA, MeJA). Despite these advances, significant knowledge gaps remain in genetic inheritance patterns, epigenetic regulation, cross-pigment pathway crosstalk, and environmental modulation. Future research directions should integrate multi-omics approaches, wild germplasm resources, and gene-editing technologies to develop novel breeding strategies for bract color improvement. Full article

Among the craft recipes for artisans collected in the 4th-century Egyptian documents the Leyden and Stockholm papyri, there is one calling for adding animal milk to orchil for wool dyeing. To understand the rationale for this practice, wool yarns were dyed with and without goat milk added to orchil dyebaths, each made using lichens from three different sources. The results showed orchil containing milk dyed yarns a noticeably deeper red hue. The colorants extracted from the dyed yarns were analyzed by liquid chromatography-diode-array-detector-mass spectrometry to assess the relative amounts of nine identifiable orceins. The data showed that the yarns dyed with milk gave extracts exhibiting several fold more α-aminoorcein and α-hydroxyorcein, with only small differences in the other seven. Scanning electron microscopic analysis of a representative pair of dyed yarns showed that milk promoted surface changes in the fiber that may indicate increased cutaneous damage. Hypotheses for the milk’s effects on orchil dyeing were proposed that included the formation of milk–protein complexes with the two enriched orceins that possibly enhanced wool binding and/or better wool uptake of free and/or complexed orceins due to biodegradation of the wool’s surface cuticle caused by microbial growth promoted by the addition of milk. Full article

The growing concern over the presence of polycyclic aromatic hydrocarbons (PAHs) in grilled meats has intensified the search for natural mitigation strategies. This study evaluates the effect of red grape pomace (RGP), a natural by-product with antioxidant properties, on the lipid stability, color, fatty acid profile, volatile compounds, and PAHs formation in barbecued pork burgers. Unlike previous studies focusing on polyphenol extracts, this work investigates, for the first time, the direct incorporation of whole RGP stabilized by high hydrostatic pressure (HHP), a method that preserves its bioactive profile and ensures food safety. Incorporation of RGP at different levels (0.5%, 1%, and 3%) demonstrates its potential as a functional ingredient in meat products. Our results show that RGP effectively inhibits lipid oxidation, as indicated by significantly lower malondialdehyde (MDA) levels (p < 0.001) compared to control batches. It also modified the fatty acid profile by reducing saturated fatty acids and increasing the linoleic acid content (up to 15.56% at the 3% level). As the RPG concentration increased, color parameters (lightness, redness, yellowness, chroma, and hue) decreased significantly (p < 0.001), particularly at higher pomace levels (1% and 3%). The RGP did not significantly affect the PAH concentration, indicating its safe use in barbecued products. However, it selectively influenced volatile compounds, decreasing the hydrocarbon levels at higher concentrations, likely due to its antioxidant properties. These findings suggest that stabilized RGP may serve as a natural additive that enhances the nutritional quality and reduces lipid oxidation, without promoting PAH formation in thermally processed meats. Full article

Dyed wool samples and lake pigments prepared from the same dyestuffs were exposed to light over the course of 14 months. Brazilwood or sappanwood, cochineal, madder, and weld were used for both wools and pigments, with the addition of dyer’s broom, indigo, and tannin-containing black dyes for the wools and eosin for the pigments. The wools were dyed within the MODHT European project on historic tapestries (2002–2005), using recipes derived from fifteenth- to seventeenth-century sources. The pigments were prepared according to European recipes of the same period, or using late nineteenth-century French or English recipes. Colour measurements made throughout the experiment allowed for overall colour difference (ΔE₀₀) to be tracked and half-lives to be calculated for some of the colour changes. Alterations in the samples’ hue and chroma were also monitored, and spectral information was collected. The results showed that, for both textiles and pigments, madder is the most stable red dye, followed by cochineal, and then brazilwood. Eosin was the most fugitive sample examined. Comparisons of textile and lake samples derived from the same dyestuff, whether red or yellow, indicate that the colourants are more stable when used as textile dyes than in analogous lake pigments. Full article

This study analyzes Brazilian consumer behavior regarding quality and visual cues in fresh red meat and cooked beef. Using eye tracking to collect visual attention metrics and psychological scales to assess food behavior, the research examines how visual attention to beef attributes impacts product choice. A discrete choice method combined nine hypothetical products with varied attributes. Results showed that consumers display different visual behaviors toward cues, influencing their probability of choosing a product. For fresh beef, color was the most significant factor, especially bright red and brown hues. Color influenced both the time to first fixation and total fixation time, while breed also affected total fixation time. Dark-red color and unspecified breed information increased the purchase probability, while Nellore breed and brown color decreased it. Total fixation numbers were significantly impacted by color, breed, marbling, and price. In cooked beef, tenderness, price, and flavor were key visual cues. Tenderness and flavor influenced the time to first fixation, whereas price and flavor impacted the number of fixations. This research contributes to understanding visual cues and attention in food choices, suggesting strategies for enhancing beef labeling and communication to better inform Brazilian consumers. Full article

This study aimed to evaluate the drying kinetics, microstructural features, moisture content, color, pH, aw, texture, acidity, rehydration capacity, and sensorial attributes of strawberry slices processed by different drying methodologies. Strawberry samples were processed by hot air-drying (HA, 60 °C, 0.5 m/s), freeze-drying (FD, 0.055 mbar), and pulsed electric field (PEF)-assisted freeze-drying (PEFFD, 1 kV/cm and 3.2 kJ/kg). PEF pre-treatment significantly increased cell membrane permeability by forming micropores, which led to a significant reduction in the moisture content of up to 8.87% and improved the drying efficiency. Nonetheless, this pre-treatment did not significantly alter the drying rate due to the inherent constraints of the freeze-drying process. PEFFD samples better retained their shape, volume, and visual quality, and exhibited a maximum rehydration capacity of 64.90%. The ascorbic acid retention was found to be higher in the FD and PEFFD when compared to HA. FD and PEFFD samples had an increase in both red and yellow hue. PEF shows promise as a pre-treatment technique, improving both the drying efficiency and strawberry quality. Further studies are needed to assess PEFFD’s industrial scalability and economic feasibility. Full article

There are growing health concerns regarding high-fat meat products. This study systematically evaluated the quality of reformulated chicken sausages through progressive substitution (30%, 60%, and 90%) of traditional pork-back fat with an Agaricus bisporus–soybean oil complex. The 60% substitution optimized texture, fatty acids, and sensory properties: hardness increased from 4332.38 N (control) to 5810.04 N, and chewiness from 3048.55 N to 3896.93 N. Linoleic acid (C18:2n6) rose from 13.00 to 32.81 g/100 g and α-linolenic acid (C18:3n3) from 0.60 to 3.05 g/100 g, improving the PUFA/SFA ratio from 0.40 to 1.15). Sensory scores (flavor/taste/overall) increased from 6.0/5.1/6.6 to 7.2/5.6/7.4. After 35-day storage, TBARS values (0.161, 0.147, 0.126 mg/100 g for 30%/60%/90% groups) remained below the control (0.232 mg/100 g). Meanwhile, the reduced-fat sausages exhibited a deeper, less saturated red hue. Scanning electron microscopy (SEM) revealed an enhanced network structure in the sausage matrix. The reformulated sausages maintained essential product characteristics such as cooking yield, moisture retention, protein content, and amino acid profile while achieving a 9.5–16.1% reduction in energy value. These findings collectively demonstrate that the A. bisporus–soybean oil complex effectively enhances the product quality, nutrition, antioxidant capacity, and sensory quality of reduced-fat chicken sausages, demonstrating this plant-based composite as a promising functional ingredient for developing healthier meat products. Full article

We developed an optoelectronic sensor capable of quantifying in-plane rotational and linear displacements between two parallel surfaces. The sensor utilizes a photo detector to capture the intensity of red (R), green (G), blue (B), and clear (C, broad visible spectrum) light reflected from a color gradient wheel on the opposing surface. Variations in reflected R, G, B and C light intensities, caused by displacements, were used to predict linear and rotational motion via a polynomial regression algorithm. To train and validate this model, we employed a custom-built positioning stage that produced controlled displacement and rotation while recording corresponding changes in light intensity. The reliability of the predicted linear and rotational displacement results was evaluated using two different color gradient wheels: a wheel with changing color hue, and another wheel with changing color hue and saturation. Benchtop experiments demonstrated high predictive accuracy, with coefficients of determination (R²) exceeding 0.94 for the hue-only wheel and 0.92 for the hue-and-saturation wheel. These results highlight the sensor’s potential for detecting shear displacement and rotation in footwear and wearable medical devices, such as orthotics and prostheses, enabling the detection of slippage, overfitting, or underfitting. This capability is particularly relevant to clinical conditions, including diabetic neuropathy, flat feet, and limb amputations. Full article

Urban color represents the visual skin of a city, embodying regional culture, historical memory, and the contemporary spirit. However, while the existing studies focus on pedestrian-level facade colors, the “fifth facade” from a bird’s-eye view has been largely overlooked. Moreover, color distortions in traditional remote sensing imagery hinder precise analysis. This study targeted 56 Chinese coastal cities, decoding the spatiotemporal patterns of their fifth facade color (FFC). Through developing an innovative natural color optimization algorithm, the oversaturation and color bias of Sentinel-2 imageries were addressed. Several color indicators, including dominant colors, hue–saturation–value, color richness, and color harmony, were developed to analyze the spatial variations of FFC. Results revealed that FFC in Chinese coastal cities is dominated by gray, black, and brown, reflecting the commonality of cement jungles. Among them, northern warm grays exude solidity, as in Weifang, while southern cool grays convey modern elegance, as in Shenzhen. Blue PVC rooftops (e.g., Tianjin) and red-brick villages (e.g., Quanzhou) serve as symbols of industrial function and cultural heritage. Economically advanced cities (e.g., Shanghai) lead in color richness, linking vitality to visual diversity, while high-harmony cities (e.g., Lianyungang) foster livability through coordinated colors. The study also warns of color pollution risks. Cities like Qingdao exposed planning imbalances through color clashes. This research pioneers a systematic and large-scale decoding of urban fifth facade color from a remote sensing perspective, quantitatively revealing the dilemma of “identical cities” in modernization development. The findings inject color rationality into urban planning and create readable and warm city images. Full article

This paper explores the evolution and contextual background of an 18th-century dyer’s manuscript originating in Antwerp, covering the period between 1778 and 1802. This manuscript offers a unique glimpse into the operational practices of a small enterprise specializing in red hues for a middle-class clientele. The manuscript includes dye recipes, accounting records, and business correspondence, along with dyed textile samples that provide a tangible connection between written instructions and their visual outcomes. Our study aims to go beyond content analysis to examine the manuscript as a dynamic document in which the dyer’s craft knowledge and experiential learning are visibly embedded. Unlike most available technical treatises, this manuscript appears to be an evolving draft marked by corrections and additions. This fluidity in structure sheds light on the process of knowledge formation and codification in the craft, aligning with devices of precise knowledge transmission and especially with the concept of “codification of error” (Codification of error refers to how early modern artisans and scholars began systematically recording mistakes in their work rather than hiding them. This shift recognized failure as a valuable part of the learning process, helping to refine techniques and support more empirical, experimental approaches to knowledge in the crafts and sciences)—an approach developed within the artisan community to refine practices over time and theorized by Professor Sven Duprè. Through a selection of annotated pages, we highlight the manuscript’s traces of iterative thought and method development. We propose that these elements illustrate the dialectic between transmitted knowledge and individual experimentation, where mistakes, followed by correction, reflection, and refinement, play a central role. Additionally, we discuss the manuscript as evidence of the thin boundaries between practical trade knowledge and the field of scientific inquiry. Through the abovementioned and the comparison with contemporary manuals, this research positions the manuscript as a valuable case study in understanding craft knowledge evolution and its transmission within the historical context of 18th-century European textile dyeing. Full article