Search Results (148)

Salt stress represents one of the main challenges for global agricultural production, and digital phenotyping has emerged as a promising alternative for identifying popcorn genotypes tolerant to salt stress. This study evaluated the accumulation of plant pigments in response to salt stress in 49 popcorn genotypes (7 inbred lines and 42 F₁ hybrids). Seeds were subjected to two saline conditions: without salt stress (NS—0 mM NaCl) and salt stressed (SS—100 mM NaCl). The evaluation included physiological parameters, and morphological and colorimetric attributes based on the CIELab color space were analyzed using the GroundEye^® system. Additionally, the salt stress tolerance index (SSTI) was calculated for all assessed genotypes. The SSTI ranged from 0.55 to 0.83, with values closer to 1.0 indicating higher tolerance to the stressor. Among the evaluated genotypes, L472 and four of its hybrids stood out for their salinity tolerance, as they combined efficient maintenance of chlorophyll content with higher SSTI estimates. In contrast, L217 and two of its hybrids were identified as sensitive, exhibiting some of the lowest SSTI estimates and significant accumulation of anthocyanins, which, in this study, indicated a response mechanism to oxidative damage. Digital phenotyping associated with CIELab colorimetric analysis constitutes an objective tool for identifying tolerant genotypes, thereby accelerating breeding programs aimed at developing cultivars adapted to saline environments. Full article

In the present work, oil-in-water (O/W) cosmetic emulsions containing nanolignin (NL) at 0.35, 1, and 2% w/w were developed using a single multifunctional nanoadditive concept, whereby NL simultaneously acts as an antioxidant, rheology modifier, and color/sunscreen booster. Nanolignin was characterized by FTIR, DLS, and SEM, confirming its chemical structure and nanoscale particle size. The emulsions were evaluated in terms of pH and viscosity stability, rheological behavior, colorimetric CIELAB parameters, DPPH radical scavenging activity, and in vitro sun protection factor (SPF). Incorporation of NL led to a slight pH decrease relative to the blank formulation, while maintaining values within the acceptable cosmetic range (pH 4–6), and yielded emulsions with excellent pH and viscosity stability over 28 days of storage. Increasing the NL concentration modified the rheological profile and viscosity, as well as the L*, a*, and b* color coordinates, enabling tunable visual appearance and texture. All formulations exhibited high antioxidant capacity; notably, the NL_1% emulsion displayed higher radical scavenging activity than the NL_2% system, underscoring a non-linear structure–property relationship. SPF values ranged between 14.09 ± 0.875 and 22.29 ± 1.719, demonstrating that nanolignin can enhance photoprotective performance. Overall, this study highlights the potential of nanolignin as a single multifunctional nanoadditive for designing stable, antioxidant, and photoprotective cosmetic O/W emulsions with adjustable rheology and color. Full article

Hemp plants are precious resources for the textile industry, being considered a sustainable and more economical alternative to cotton. Sustainable dyeing processes should minimize the consumption of water, energy, and chemicals while ensuring high color intensity and reducing the pollution load of residual baths. Black carrot (Daucus carota L. ssp. sativus) is a valuable source of dyes for dyeing hemp materials because it is rich in anthocyanins and anthocyanidins, which generate colors ranging from red-orange and muted magenta to blue, depending on the pH. In this article, the dye extraction process was colorimetrically monitored for 26 days to determine the optimal fermentation/storage period that generates the most intense color during the dyeing process. The dyeing parameters tested were temperature (40–100 °C), pH (4.33–9.15), duration (1–24 h), concentration (2.5–10%), and the presence of organic acids (ascorbic and citric acids). Virgin baths and the first three residual baths were used in the dyeing process. While the results of FTIR, SEM, and EDX analyses confirmed the dyeing process, the CIEL*a*b* measurements quantified the characteristics of the colors obtained using virgin and residual baths. The 12 principles of green chemistry were also discussed, together with their implementation in hemp dyeing. Full article

The present study evaluates the optical and colorimetric properties of Polylactic acid (PLA)-based films blended with Poly(3-hydroxybutyrate) (PHB) and Poly(butylene succinate) (PBS) and impregnated with mango leaf extract (MLE) using supercritical solvent impregnation (SSI) under different operating conditions (pressure: 10–30 MPa; temperature: 35–55 °C). Additionally, the relationship between impregnation load (IL) and color properties, as well as the release kinetics of the impregnated compounds, was investigated. The incorporation of PHB and PBS into the PLA matrix prior to impregnation led to a slight increase in the b* parameter (from 1.64 to 2.61), indicating a tendency toward yellowish tones. After SSI, all films exhibited noticeable color changes, with a shift toward yellowish-green hues and a decrease in lightness, regardless of processing conditions. Statistical analysis confirmed that polymer composition and its interaction with pressure and temperature significantly affected color properties (p-value < 0.001). The addition of PHB and PBS, as well as MLE impregnation, enhanced UV-barrier properties, while also modifying film transparency and opacity. In particular, PLA-PBS films showed higher opacity (more than 20 times) and lower transparency compared to neat PLA. These films also exhibited the highest IL values (2.41–4.75 mg MLE/100 mg polymer). Multivariate regression analysis demonstrated a strong correlation between CIELAB parameters (L*, a*, and b*) and IL (R² > 85%, p-value < 0.001). Release studies in a food simulant showed partial release profiles, well described by Peleg’s model (R² > 0.90). Furthermore, Korsmeyer–Peppas model fitting yielded diffusion exponents (n < 0.5), indicating quasi-Fickian diffusion mechanisms governing the release process. Full article

This study investigated bract color phenotypes and pigment composition in Bougainvillea × buttiana ‘Mrs. Butt’ and six bud-sport varieties at the full-bloom stage. Bract color was evaluated using the Royal Horticultural Society Colour Chart and CIELAB parameters, whereas pigment classes and contents were determined using qualitative color reactions, UV–Vis spectroscopy, and spectrophotometric assays. Data were analyzed using one-way ANOVA, Duncan’s multiple range test, Pearson correlation analysis, cluster analysis, and pigment ratio analysis. The seven varieties were classified into red/pink and orange/yellow groups, which differed significantly in L*, a*, b*, C*, and H°. Betalains and flavonoids appeared to be the predominant pigment classes, whereas chlorophylls and carotenoids were present at relatively low levels; no characteristic anthocyanin absorption peak was detected under the present UV–Vis conditions. The betaxanthin/betacyanin ratio was positively correlated with L* and b* and negatively correlated with a*, suggesting that this ratio is associated with variation from red-dominant to yellow-dominant bract coloration. These findings suggest that bract color variation in this bud-sport lineage is associated with the combined effects of betalains and flavonoids, and that the betaxanthin/betacyanin ratio could serve as a practical indicator for color classification and low-cost assisted selection in Bougainvillea. Full article

Color measurement and monitoring of chromatic changes over time play a key role in the study and conservation of historical materials. In this context, hyper-spectral imaging (HSI) offers spatially resolved spectral information that can be converted into colorimetric data, although its quantitative reliability under in situ conditions remains challenging. This study evaluates the colorimetric performance of a HSI system (Specim IQ) through comparison with a reference spectrocolorimeter (Konica-Minolta CM-700d), combining laboratory measurements on certified standards and in situ analyses on purple-dyed manuscripts. Colorimetric coordinates (CIELAB) and color differences (ΔE₀₀) were used to assess accuracy, precision, and systematic deviations. Under controlled conditions, HSI showed good agreement with reference measurements, although systematic biases were observed. In situ applications revealed reduced accuracy (average ΔE₀₀ ≈ 4.3) due to material heterogeneity and acquisition constraints. Despite these limitations, HSI preserved consistent relative chromatic relationships, enabling meaningful comparative analysis. Spatially resolved mapping of colorimetric parameters proved effective for visualizing chromatic variability, dye distribution, and degradation patterns. These results demonstrate that, while not fully reliable for absolute colorimetric assessment in situ, HSI represents a powerful tool for non-invasive, spatially resolved color analysis of complex historical materials. Full article

This study characterized the physicochemical, rheological, and sensory parameters of five commercial natural-flavored yogurt brands available in the Peruvian highland’s region. The methodology included proximate composition, pH, titratable acidity, soluble solids, color (CIELab*), flow properties, viscoelastic behavior, and consumer sensory analysis using CATA questions and an acceptability test. The results revealed high variability among samples: soluble solids ranged from 7.24 to 16.27 °Brix, acidity from 0.68 to 1.03%, and two distinct rheological groups were identified: firm yogurts (G′ > 190 Pa) and soft yogurts (G′ < 30 Pa). Sensory attributes such as “pleasant texture,” “creamy,” and “milky flavor” positively influenced acceptability, whereas “acidic” and “watery” attributes negatively affected it. The sample with a balanced sensory profile (moderately sweet and creamy) achieved the highest acceptability score (7.8/9). It is concluded that yogurt quality in the highlands market is heterogeneous and that consumer acceptability depends more on sensory balance than on firmness alone. It is recommended that the dairy industry standardize fermentation processes to control acidity and optimize texture, prioritizing creaminess and homogeneity, and that regulatory authorities strengthen monitoring of these critical parameters to ensure safe and consistent products. Full article

Phalaenopsis hybrids are the most popular potted flowers in flower markets worldwide because they exhibit various flower colors, including yellow, green, white and red-purple. A thorough assessment of petal color polymorphism in Phalaenopsis enables the promotion of mechanistic studies on floral coloration regulation. In this study, we collected 156 Phalaenopsis germplasms to assess their chromativity value (L*, a* and b*), and then divided them into six groups according to their petal color: white (21), green (11), yellow-orange (37), pink (40), purplish-red (25) and dark red (22). Significant correlations were detected between petal color chromaticity indices and both the total concentration and the compositional ratio of the two primary anthocyanin components: cyanidin 3,5-O-diglucoside (Cy3G5G) and delphinidin 3,5-O-diglucoside (Dp3G5G). The red petal phenotype was largely determined by high accumulations of Cy3G5G and Dp3G5G, as well as a high Cy3G5G/Dp3G5G ratio. By integrating CIELab color parameters with anthocyanin composition and gene expression analyses, a quantitative regulatory model for Phalaenopsis flower color was established. We have revealed that the phenotypic traits of high a* and low L* values are directly associated with the high expression of key structural genes (PhF3′H, PhDFR, PhF3′5′H). These results provide molecular markers and a screening basis for screening, enabling directional flower color breeding, and significantly enhancing the predictability and accuracy of breeding programs. Full article

Accurate characterization of closely related Ilex taxa is essential for the conservation, documentation, and utilization of plant genetic resources. In this study, five Ilex taxa from eastern China (Ilex rotunda Thunb., Ilex chinensis, Ilex cornuta Lindl. & Paxt., Ilex cornuta ‘Fortunei’, and Ilex latifolia Thunb.) were evaluated using an integrated framework combining fruit morphometric traits, CIELAB color parameters, and electronic-nose (E-nose) volatile fingerprints. Fruit transverse diameter, longitudinal diameter, single-fruit weight, fruit shape index, and peel color traits (L*, a*, b*, and chroma, C*) differed significantly among taxa (one-way ANOVA, all p < 0.001). I. cornuta produced the largest and heaviest fruits, I. chinensis showed the most elongated fruit shape, and I. rotunda exhibited the highest redness and chroma values. Chemometric analyses of E-nose responses further improved taxon discrimination and revealed clear divergence in volatile-response patterns. Trait-space relationships were broadly consistent with the preset phylogenetic framework, with I. rotunda showing the greatest divergence and I. cornuta and I. cornuta ‘Fortunei’ showing the closest similarity. These findings indicate that integrated fruit phenotyping and rapid volatile profiling provide a practical approach for Ilex germplasm identification, comparative evaluation, and resource documentation, with potential value for conservation planning and horticultural utilization. Full article

Replacing artificial dyes with natural pigments in foods, especially carotenoids, has proven to be technologically feasible. This study developed a high-performance pitanga carotenoid extraction process using ionic liquids (ILs) and a factorial design to identify a potential substitute for artificial azo dyes, specifically Allura Red AC and Sunset Yellow FCF. 1-Hexyl-3-methyl-imidazolium chloride [C6mim]Cl was the most efficient IL. The optimized process conditions included a solid–liquid ratio R(S/L) of 1:10 m/m, an IL to ethanol co-solvent ratio R(IL/E) of 1:1 m/m, ultrasound power of 350 W, and six extraction cycles of 7 min each. These conditions yielded a total carotenoid content of 100.40 ± 3.71 μg/g (dry matter), demonstrating effective pigment recovery and a concentration suitable for practical use as a natural colorant alternative to synthetic azo dyes. The reuse of ILs and carotenoid purification were achieved through solid-phase extraction (SPE) using XAD-7HXP adsorbent, resulting in recovery rates of 89.2–76.2% for [C6mim]Cl and 108.9–23.2% for carotenoids. The major carotenoids identified were all-trans-β-cryptoxanthin, all-trans-rubixanthin, and all-trans-lycopene, whose combined presence contributed to a yellowish-orange hue similar to that of Sunset Yellow FCF, as confirmed by CIELAB parameters. Additionally, the [C6mim]Cl carotenoid extract exhibited high antioxidant activity, with an antioxidant capacity of 23.54 µmol of α-tocopherol equivalent. Full article

Chardonnay (Vitis vinifera L.) is one of the most widely cultivated white grape varieties in Chile, yet integrated studies addressing phenolic composition, polysaccharides, and color in commercial wines remain limited. This study characterized 30 commercial Chardonnay wines from major Chilean regions through a comprehensive analysis of phenolic composition, polysaccharide fractions, and CIELab color parameters, considering multiple sources of variability including vintage (2023–2024), closure type, geographic location, and valley of origin. Basic oenological parameters showed low variability, confirming their strong technological regulation in commercial wines. In contrast, total tannins, selected chromatic coordinates (particularly a* and hue angle), polysaccharide fractions, and several low-molecular-mass phenolics exhibited significant differences mainly associated with geographic origin and closure type. Among phenolic families, hydroxycinnamates, phenolic alcohols, and flavonols emerged as the most discriminant compositional domains. Multivariate analysis revealed that wine differentiation was structured by overlapping compositional gradients involving phenolic evolution, color expression, and polysaccharide composition rather than by vintage alone. Overall, the results highlight the multifactorial nature of Chardonnay wine composition and the combined contribution of grape origin, closure-associated bottle evolution, and winemaking factors. Nevertheless, because wines were commercially sourced and bottle age and storage conditions were not standardized, closure-associated differences should be interpreted cautiously as associations rather than causal effects. Full article

Wine phenolic composition is strongly influenced by tannin structure, yet how the polymerization degree of exogenous proanthocyanidins modulates wine quality during aging remains unclear. This study investigated the effects of adding grape seed proanthocyanidins (GSP) with different mean degrees of polymerization (mDP 4.63, 3.29, and 1.31) to Cabernet Sauvignon wine by analyzing phenolic compounds, tannin structure, anthocyanin components, CIELAB color parameters, and astringency over 6 months of bottle aging. Low-mDP GSP (rich in galloylated monomers) provided the biggest initial phenolic boost, while high-mDP GSP (dominated by non-galloylated units) sustained tannin enrichment throughout aging. Low-mDP GSP accelerated tannin maturation and color evolution toward aged wine characteristics, with Mv-3-Coglu identified as a key precursor for brick-red hue development. Sensory evaluation revealed that high-mDP GSP enhanced coarse and drying astringency, whereas low-mDP GSP promoted velvety mouthfeel. These findings establish that GSP polymerization degree critically determines phenolic evolution, color stability, and mouthfeel during bottle aging, providing a scientific basis for selecting structure-specific proanthocyanidins to achieve targeted wine quality outcomes. Full article

This study presents a detailed colorimetric evaluation using the CIEL*a*b* system for a novel series of symmetrically structured disazo-stilbene dyes. The synthesis utilized the non-genotoxic 4,4′-diaminostilbene-2,2′-disulfonic acid as the diazotizing component, with the coupling components being N-substituted acetoacetanilide derivatives. The purity of the obtained dyes was confirmed by HPLC analysis. The color analysis was initially conducted on the dyes in solid state (powder) to investigate potential structure–color correlations. Subsequently, these parameters were applied to analyze the performance of the dyes incorporated into acrylic resin films. Titanium dioxide (P.W.6; C.I. 77891) served as the white standard, along with mixtures of dyes in different concentrations that were applied to a cellulosic substrate. The results characterize these compounds as eco-friendly dyes possessing high tinctorial strength and a significant metamerism effect. Full article

The comprehensive quality assessment of raw milk from small-scale producers remains essential for improving dairy sector competitiveness. This study employed a multivariate approach to correlate the physicochemical, colorimetric, and sensory profiles of raw milk from eleven producers in the town of Supe, Barranca, Lima, Peru. Milk samples were analyzed using a Lactoscan MCC ultrasonic analyzer, CIEL*a*b* colorimetry, and the Flash Profile sensory method. Data integration and interpretation were performed using Analysis of Variance (ANOVA), Generalized Procrustes Analysis (GPA) and Hierarchical Multiple Factor Analysis (HMFA). The results revealed significant heterogeneity, identifying two distinct producer groups. A high-quality group (DF7, DF10, DF11) presented adequate physicochemical parameters: high fat content (>3.77%), total solids (>12.06%), normal freezing point (≈−0.53 °C), creamy color (high L* and b*), and positive sensory attributes (“fatty”, “creamy”). In contrast, a low-quality group (DF4, DF5, DF8, DF9) showed evidence of water adulteration (12–16%), reflected in an elevated freezing point (up to −0.44 °C), low solids-not-fat, and defective sensory profiles (“tasteless”, “salty”). The HMFA demonstrated a strong concordance between instrumental and sensory data sets, identifying water adulteration and fat content as the primary drivers of quality variation. This integrated methodology provides a robust diagnostic tool for quality-based payment systems and targeted technical assistance, offering a replicable model for enhancing quality control and valorizing raw milk in smallholder dairy systems. Full article

This study was carried out to investigate the antimicrobial performance and color stability of silver (Ag)-modified polyurethane and waterborne coating systems applied to Oriental beech (Fagus orientalis L.) wood after the specimens were subjected to UV aging for 24 h. Antimicrobial activity and color stability were evaluated before and after aging against Escherichia coli (E. coli, ATCC 25922), Staphylococcus aureus (S. aureus, NCTC 13552), and Candida albicans (C. albicans) in accordance with the JIS Z 2801 standard. Color changes were determined using CIELab parameters (ΔL*, Δa*, Δb*, and ΔE*) in accordance with the TS EN ISO 16474-3 standard. Prior to UV exposure, the highest antibacterial activity against E. coli occurred in Ag-modified waterborne varnish coatings, whereas the highest antifungal activity against C. albicans occurred in Ag-modified polyurethane paint systems. After UV aging, antimicrobial performance varied depending on the coating type. Particularly, Ag-modified waterborne varnish coatings retained significant antibacterial activity against E. coli and S. aureus and exhibited the highest antifungal performance against C. albicans. Color analysis revealed that UV exposure also caused significant changes in all coating systems. The most pronounced variations were observed for the lightness difference (ΔL*), red–green color difference (Δa*), and yellow–blue color difference (Δb*) parameters, while the lowest total color difference (ΔE*) values were observed for Ag-modified polyurethane and Ag-modified waterborne varnish coatings. Overall, Ag-modified waterborne varnish systems demonstrated superior performance in both antimicrobial activity and color stability after UV aging. Full article