CIE XYZ Research Articles

Spectrophotometric evaluation of color stability of novel composites following exposure to antioxidant beverages: An in vitro study.

Color matching and stability are the essential considerations in restorative dentistry, as they contribute to the longevity and esthetic appeal of the restorations. Composites with nanoparticles and more filler content are anticipated to be more color-stable. The aim of the study was to assess and contrast the color stability of esthetic restoration materials following exposure to various antioxidant beverages. A Class V cavity was prepared on the buccal surface of 40 maxillary premolars. The specimens were divided into two groups: microhybrid (MH) and nanohybrid (NH) composite. The baseline color of each tooth sample was measured and then, the samples were categorized into four subgroups based on the immersion solution (pomegranate juice, beetroot juice, black plum juice, and distilled water) and evaluated on day 1, day 7, day 14, and day 21 using a spectrophotometer-based on CIE L*a*b* color scale. For spectrophotometer analysis, CIE XYZ data were obtained and converted to CIELAB. The samples mean difference in ΔE values before and after being immersed in various beverages. The data were statistically analyzed using an independent t-test and one-way analysis of variance. MH and NH composite materials showed color change after being exposed to the test beverages. MH composite causes more color change than NH composite at all-time intervals. Black plum showed the greatest discoloration in both composites.

Generation of a red-green-blue laser by stimulated Raman scattering of ethanol

In this paper, we report an efficient red-green-blue (RGB) laser based on the stimulated Raman scattering (SRS) of ethanol. The wavelengths of the three-color laser are 631, 532, and 447 nm, respectively, and the gamut space that can cover is 116% of the Rec. 2020 standard gamut in the CIE1976 color space. The maximum output energy of the RGB laser was 595.9 µJ under the total pump energy of 1.56 mJ, which corresponds to an optical conversion efficiency of 38.2%. By adjusting the energy ratio of different wavelengths, a white laser output with a maximum output energy of 544.8 µJ is achieved, corresponding to a conversion efficiency of 34.9%. To the best of our knowledge, this is the first time that an RGB laser has been realized based on liquid SRS. It provides a simple, practical route for efficiently obtaining RGB and white lasers, which may find important applications in many fields like laser display, atmospheric monitoring, and medical beauty.

Differential metabolites regulate the formation of chromatic aberration in Toona fargesii wood

Radial chromatic aberration (∆E) in xylem is a significant phenotypic characteristic for distinguishing sapwood from heartwood. Investigating its relationship with metabolites is critical to the formation of color differences in wood. In this study, chromatic aberration of the inner heartwood (IH), outer heartwood (OH), transition zone (TZ), inner sapwood (IS), and outer sapwood (OS) were quantified utilizing the CIE color space system, and the secondary metabolite profiles of Toona fargesii wood were identified. The findings showed a radial variation in the wood color of T. fargesii. The chromatic aberration was largest in the OS vs. IH for 22.51 and smallest in OH vs. TZ for 4.92. A total of 646 metabolites from 8 categories were obtained from wood, including flavonoids, phenolic acids, terpenoids, et al. The OS vs. IH had the highest number of differential metabolites with 395, whereas the OH vs. TZ had the fewest differential metabolites with 184. The metabolites were mostly enriched in metabolic pathways and the biosynthesis of flavonoids. The 75 % metabolites in the flavonoid biosynthesis pathway were abundant in HW tissues and gradually decreased from IH to OS. There were 39 shared differential metabolites among six comparison groups, of which flavonoids accounted for 31 %. There were clear radial differences in the flavonoid metabolites, with a generally decreasing trend from IH to OS tissue. The relative content of the flavonoids exhibited negative and positive correlations with L* and a*, respectively. Especially the largest correlation coefficients for 93 % between 2-hydroxynaringenin, aromadendrin and L* showed their importance in chromatic aberration. This study demonstrated the radial variation pattern of chromatic aberration and metabolic profiles. It also identified the key metabolites that affect wood color in T. fargesii, which offered valuable insights into the formation of the chromatic aberration in wood.

Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process

This work presents the results of the homogenization of the color of sapwood and false heartwood Fagus sylvatica L. into a uniform color shade due to the influence of the temperature of saturated moist air and saturated water steam in individual steaming modes. The results of analyses of the influence of temperature within 24 h point out the different changes in the color of the sapwood and the wood of the false heartwood when the uniform color of the beech wood is achieved by the steaming process. By steaming beech wood with a false heartwood saturated with moist air at a temperature of tI = 95 °C during τ = 24 h, the color of the sapwood does not merge with the color of the wood of the false heartwood. The sapwood darkens and, on the other hand, the wood of the false heartwood slightly lightens, while the significant color contrast is removed, but the color homogenization in the individual zones does not occur. The unification of the colors in individual zones occurs during the steaming process at a temperature of saturated water steam tII ≈ 105 °C in 18 h, where the resulting brown color is identified in the color space CIE L*a*b* by the values of the lightness L* = 61.3 ± 2.2 and of the red color a* = 12.4 ± 1.3 and yellow color b* = 19.5 ± 1.4. The most pronounced homogenization of the color occurs through the steaming process at a temperature of saturated water steam tIII ≈ 120 °C, where the wood acquires a uniform dark brown–gray color in a time of τ ≈ 9 h steaming. The coordinates of the color-homogenized steamed beech wood are L* = 55.9 ± 1.9, a* = 12.3 ± 1.2, and b* = 19.6 ± 1.3. The unification of the colors by the steaming process is achieved by darkening both the sapwood and the wood of the false heartwood. In the overall color homogenization, the sapwood and the wood of the false heartwood do not participate equally in the steaming process. While the total color difference between the sapwood and a color homogenized state is quantified by the value ∆EtI* = 8, ∆EtIII* = 22.7, the total color difference in the wood with a false heartwood is only ∆EtI* = 1.9, ∆EtIII* = 11.8.

A Stretchable, Sweat‐Resistant Electrophoretic Display Device Driven by Human‐Safe Voltage for Smart E‐Textile Application

AbstractThe demand for wearable display devices capable of real‐time information collection is growing rapidly. Among them, electrophoretic display (EPD) shows features of ultra‐low power consumption and high readability in sunlight, making them particularly suitable for wearable applications. However, due to high driving voltage and susceptibility to salt, few wearable EPD devices are reported so far. To address this, a stretchable EPD compatible with textiles is fabricated based on waterborne polyurethane. The device exhibits great performance to resist water and sweat, achieving a whiteness of 35 (Y in CIE XYZ) and a contrast ratio of 13.5 at a driving voltage of 30 V. Benefit from the device's excellent bistability and flexibility, there is no degrading to its optoelectronic performance after bending, twisting or stretching. For demonstration, an 8 × 8 matrix display is realized, showcasing that this process is suitable for wearable textile display applications.

Radical-Induced Photochromic Silver(I) Metal-Organic Frameworks: Alternative Topology, Dynamic Photoluminescence and Efficient Photothermal Conversion Modulated by Anionic Guests.

Photogenerated radicals are an indispensable member of the state-of-the-art photochromic material family, as they can effectively modulate the photoluminescence and photothermal conversion performance of radical-induced photochromic complexes. Herein, two novel radical-induced photochromic metal-organic frameworks (MOFs), [Ag(TEPE)](AC) ⋅ 7/4H2O ⋅ 5/4EtOH (1) and [Ag(TEPE)](NC) ⋅ 3H2O ⋅ EtOH (2), are reported. Distinctly different topological networks can be obtained by judiciously introducing alternative π-conjugated anionic guests, including a new topological structure (named as sfm) first reported in this work, describing as 4,4,4,4-c net. EPR data and UV-Vis spectra prove the radical-induced photochromic mechanism. Dynamic photochromism exhibits tunability in a wide CIE color space, with a linear segment from yellow to red for 1, while a curved coordinate line for 2, resulting in colorful emission from blue to orange. Moreover, photogenerated TEPE* radicals effectively activate the near-infrared (NIR) photothermal conversion effect of MOFs. Under 1 W cm-2 808 nm laser irradiation, the surface temperatures of photoproducts 1* and 2* can reach ~160 °C and ~120 °C, respectively, with competitive NIR photothermal conversion efficiencies η=51.8 % (1*) and 36.2 % (2*). This work develops a feasible electrostatic compensation strategy to accurately introduce photoactive anionic guests into MOFs to construct multifunctional radical-induced photothermal conversion materials with tunable photoluminescence behavior.

Radical‐Induced Photochromic Silver(I) Metal–Organic Frameworks: Alternative Topology, Dynamic Photoluminescence and Efficient Photothermal Conversion Modulated by Anionic Guests

AbstractPhotogenerated radicals are an indispensable member of the state‐of‐the‐art photochromic material family, as they can effectively modulate the photoluminescence and photothermal conversion performance of radical‐induced photochromic complexes. Herein, two novel radical‐induced photochromic metal–organic frameworks (MOFs), [Ag(TEPE)](AC) ⋅ 7/4H2O ⋅ 5/4EtOH (1) and [Ag(TEPE)](NC) ⋅ 3H2O ⋅ EtOH (2), are reported. Distinctly different topological networks can be obtained by judiciously introducing alternative π‐conjugated anionic guests, including a new topological structure (named as sfm) first reported in this work, describing as 4,4,4,4‐c net. EPR data and UV–Vis spectra prove the radical‐induced photochromic mechanism. Dynamic photochromism exhibits tunability in a wide CIE color space, with a linear segment from yellow to red for 1, while a curved coordinate line for 2, resulting in colorful emission from blue to orange. Moreover, photogenerated TEPE* radicals effectively activate the near‐infrared (NIR) photothermal conversion effect of MOFs. Under 1 W cm−2 808 nm laser irradiation, the surface temperatures of photoproducts 1* and 2* can reach ~160 °C and ~120 °C, respectively, with competitive NIR photothermal conversion efficiencies η=51.8 % (1*) and 36.2 % (2*). This work develops a feasible electrostatic compensation strategy to accurately introduce photoactive anionic guests into MOFs to construct multifunctional radical‐induced photothermal conversion materials with tunable photoluminescence behavior.

Exploration of Convective and Infrared Drying Effect on Image Texture Parameters of 'Mejhoul' and 'Boufeggous' Date Palm Fruit Using Machine Learning Models.

Date palm (Phoenix dactylifera L.) fruit samples belonging to the 'Mejhoul' and 'Boufeggous' cultivars were harvested at the Tamar stage and used in our experiments. Before scanning, date samples were dried using convective drying at 60 °C and infrared drying at 60 °C with a frequency of 50 Hz, and then they were scanned. The scanning trials were performed for two hundred date palm fruit in fresh, convective-dried, and infrared-dried forms of each cultivar using a flatbed scanner. The image-texture parameters of date fruit were extracted from images converted to individual color channels in RGB, Lab, XYZ, and UVS color models. The models to classify fresh and dried samples were developed based on selected image textures using machine learning algorithms belonging to the groups of Bayes, Trees, Lazy, Functions, and Meta. For both the 'Mejhoul' and 'Boufeggous' cultivars, models built using Random Forest from the group of Trees turned out to be accurate and successful. The average classification accuracy for fresh, convective-dried, and infrared-dried 'Mejhoul' reached 99.33%, whereas fresh, convective-dried, and infrared-dried samples of 'Boufeggous' were distinguished with an average accuracy of 94.33%. In the case of both cultivars and each model, the higher correctness of discrimination was between fresh and infrared-dried samples, whereas the highest number of misclassified cases occurred between fresh and convective-dried fruit. Thus, the developed procedure may be considered an innovative approach to the non-destructive assessment of drying impact on the external quality characteristics of date palm fruit.

Modeling and optimization of the ratio of fluorophores: a step towards enhancing the sensitivity of ratiometric probes.

In the ratiometric fluorescent (RF) strategy, the selection of fluorophores and their respective ratios helps to create visual quantitative detection of target analytes. This study presents a framework for optimizing ratiometric probes, employing both two-component and three-component RF designs. For this purpose, in a two-component ratiometric nanoprobe designed for detecting methyl parathion (MP), an organophosphate pesticide, yellow-emissive thioglycolic acid-capped CdTe quantum dots (Y-QDs) (analyte-responsive), and blue-emissive carbon dots (CDs) (internal reference) were utilized. Mathematical polynomial equations modeled the emission profiles of CDs and Y-QDs in the absence of MP, as well as the emission colors of Y-QDs in the presence of MP separately. In other two-/three-component examples, the detection of dopamine hydrochloride (DA) was investigated using an RF design based on blue-emissive carbon dots (B-CDs) (internal reference) and N-acetyl L-cysteine functionalized CdTe quantum dots with red/green emission colors (R-QDs/G-QDs) (analyte-responsive). The colors of binary/ternary mixtures in the absence and presence of MP/DA were predicted using fitted equations and additive color theory. Finally, the Euclidean distance method in the normalized CIE XYZ color space calculated the distance between predicted colors, with the maximum distance defining the real-optimal concentration of fluorophores. This strategy offers a more efficient and precise method for determining optimal probe concentrations compared to a trial-and-error approach. The model's effectiveness was confirmed through experimental validation, affirming its efficacy.

The application of statistical and novel unsupervised machine learning methodology to forensic hair analysis

ABSTRACT Hair colour is a valuable feature in forensic hair analysis and hair comparisons. Five hundred microscopic images of hair shafts were taken and for each image and colour model (RGB, CIE XYZ and CIE L*a*b*) values for each image were determined. The discriminating power of the three colour model values using statistical and unsupervised machine learning methods was evaluated. Additionally, the discriminating power of the images of the same hair shafts using unsupervised machine learning methods was evaluated. All methods were compared to determine which method had the greatest discriminating power to best distinguished between participants and accurately assigned hair to an individual and assist in forensic hair comparisons. The RGB colour model demonstrated the highest discriminating power of the colour model values while the CIE L*a*b* model achieved complete discrimination with a reduced number of participants. The unsupervised k-means model yielded similar results. Unsupervised PCA/k-means and agglomerative clustering models demonstrated low discrimination power of the images, suggesting the existence of additional features within the data beyond colour. This research highlights the significance of the incorporation of colour values in forensic hair comparisons and for further exploration of the incorporation of other hair features, beyond colour values.

Assessment of Variability in Free Flap Color Match to Facial Skin by Donor Site and Race.

To use portable colorimetry to quantify color differences between facial skin and potential three head and neck microvascular free tissue transfer (MFTT) donor sites-radial forearm (RF), anterolateral thigh (ALT), and fibula (FF)-and compare these differences by pigmentation of the donor site skin and self-identified race. In this cross-sectional cohort study, healthy volunteers consented to handheld colorimeter measurements at the three potential MFTT donor sites (RF, ALT, FF) to quantify color match to the facial skin using the CIE color space (DeltaE). The comparison of ipsilateral to contralateral cheek served as control for measurements. Cross-sectional measurements in healthy volunteers were then compared to measurements obtained in postoperative head and neck MFTT patients. DeltaE measurements were obtained for 128 healthy controls and 24 postoperative patients (N = 152). With increasing lightness (decreased pigmentation) of the skin at the donor site, the color match significantly worsened (higher DeltaE) across all potential MFTT donor sites (all p < 0.05). DeltaE from healthy controls closely approximated postoperative color match measurements in patients who underwent cervicofacial MFTT (DeltaE RF: 5.3 vs. 6.0, p = 0.432; DeltaE ALT: 6.2 vs. 6.4, p = 0.822; DeltaE FF: 6.0 vs. 6.4, p = 0.806). Patients with decreased skin pigmentation who are undergoing head and neck MFTT may experience worse color discrepancy between cervicofacial skin and the transferred skin paddle than those with more pigmented skin. Portable colorimetry may identify patients who could benefit from interventions such as dermis-resected free tissue reconstruction with skin grafting to improve postoperative appearance. 3 Laryngoscope, 134:3581-3586, 2024.

Practical RGB-to-XYZ Color Transformation Matrix Estimation under Different Lighting Conditions for Graffiti Documentation.

Color data are often required for cultural heritage documentation. These data are typically acquired via standard digital cameras since they facilitate a quick and cost-effective way to extract RGB values from photos. However, cameras' absolute sensor responses are device-dependent and thus not colorimetric. One way to still achieve relatively accurate color data is via camera characterization, a procedure which computes a bespoke RGB-to-XYZ matrix to transform camera-dependent RGB values into the device-independent CIE XYZ color space. This article applies and assesses camera characterization techniques in heritage documentation, particularly graffiti photographed in the academic project INDIGO. To this end, this paper presents COOLPI (COlor Operations Library for Processing Images), a novel Python-based toolbox for colorimetric and spectral work, including white-point-preserving camera characterization from photos captured under diverse, real-world lighting conditions. The results highlight the colorimetric accuracy achievable through COOLPI's color-processing pipelines, affirming their suitability for heritage documentation.

Rearing hogs on pasture minimally impacts pork composition.

Managing swine on pasture is increasing in popularity for both the consumer and producer. This interest appears to be driven by an effort to create an improved perception of environmentally sustainable practices and increased animal welfare, while keeping start-up costs low. However, evidence-based guidance on pasture management practices that support quality pork production and environmentally sustainable procedures is lacking. The objective of this work was to quantify the impact of pasture rearing on pig growth efficiency and pork quality. In this pilot study, 20 pigs similar in genetics, age, weight, and sex ratio were divided across indoor (n = 10) and Outdoor (n = 10) housing environments. Pigs were weighed every 14 d and harvested upon reaching an average weight of 113kg. Average starting body weights were similar between both groups (P = 0.98). Carcass quality was evaluated by measuring pH, loin eye area (LEA), back fat (BF) thickness, subjective color and marbling scores, and colorimetry (CIE color space [L*, a*, b*]) at the 10th rib. Final body weights at slaughter also showed no significant variation between housing groups (P = 0.98). No differences were observed in pork quality: pH 0h (P = 0.53), 6h (P = 0.29), 12h (P = 0.80), and 24h (P = 0.07) postmortem, LEA (P = 0.44), color (P = 0.73), and marbling (P = 0.40). However, hogs raised indoors had an increase in BF thickness (P = 0.04). Based on this pilot study, outdoor rearing conditions did not have significant impacts on pork quality. Further research will help to determine the impact that rearing scheme has on pH and BF.

Digital Application of Folk Culture Elements in City Branding Visual Identity Shaping

Abstract In this paper, for the visual image shaping of folk culture elements in city branding, the intelligent extraction technology of digital image with image pre-processing, color space conversion, and color extraction as the three core modules is proposed. In terms of image preprocessing, spatial domain filtering is used as a means to explore the two main algorithms of linear filtering and nonlinear filtering, and in the color space conversion module, the RGB color space is converted to the CIE Lab color space with the help of CIE XYZ color. The color map extraction module uses Python language to construct the color collocation relationship network using K-means and color adjacency matrix visualization. Finally, the quantitative experiment on the effect of the city brand visual image that integrates the elements of folk culture is carried out, and 65 city brand visual image samples are quantitatively analyzed, while the AMOS model is applied to test the city brand visual image.

Preparation of photochromic and afterglow concrete from recycled polystyrene plastic waste immobilized with strontium aluminate nanoparticles

Strontium aluminate nanoparticles (SAN) were immobilized into recycled polystyrene plastic (PSP) waste to produce transparent photoluminescent concrete. The prepared SAN@PSP plastic showed strong optical transmittance, ultraviolet protection, photochromism, high mechanical strength, durability, photostability, and afterglow emission. Recycled polystyrene waste was mixed with different amounts of SAN (17–42 nm) to make a smart concrete with an afterglow emission. A bright afterglow smart concrete was casted from a mixture of the generated colorless PSP plastic and SAN. The excitation and emission spectra were recorded to learn more about its photoluminescence capabilities. The colorless polystyrene plates became bright green beneath ultraviolet supply and greenish-yellow beneath darkness, as measured by photoluminescence parameters. An emission peak at 518 nm, and an excitation peak at 365 nm were monitored in the polystyrene smart concrete. CIE color space results were employed to confirm the homogeneous transparency of the photochromic concrete. The hydrophobicity, hardness, photostability, and UV shielding all increased with an increase in the SAN ratio. When exposed to UV light, fast and reversible fluorescence was shown by the luminescent polystyrene substrates with a low SAN ratio, whereas luminescent polystyrene substrates with a larger SAN concentration exhibited afterglow.

COLOR DIVERSITY OF BEECH WOOD WITH A FALSE HEARTWOOD IN THE COLOR SPACE CIE L*a*b*

The color of the false heartwood of Fagus sylvatica L. perceived by the human eye is in a wide range of shades from light brown-yellow to red-brown. The article analyzes the color in the color space CIE L*a*b* of dry wood of the false heartwood type: round, flame, star and marble. The color of the wood was measured with a colorimeter Color reader CR-10. The most colorful is the wood marble with a false heartwood. The results of statistical processing of the measured color values of dry beech wood, marble false heartwood on a planed surface identify it with values on the lightness coordinate L* = 65.2 ± 6.9 and on the chromatic coordinates: red color a* = 13.2 ± 2.3 and yellow b* = 19.2 ± 1.9. The most homogeneous in color is the color of the ring wood of the false heartwood with the coordinate values: L* = 63.7 ± 3.1; a* = 12.6 ± 1.7 and b* = 20.1 ± 1.6. The color diversity of the darkness and yellow-brown-red shades of the wood of the false heartwood is numerically quantified by the values of the total color difference ΔEsx* = 3.9 - 7.5. The presented values of the color of false heartwood beech complement the knowledge about the color of false heartwood and by defining the boundaries of color in the color space CIE L*a*b*, they create space for designers to model the color diversity of compositions and construction-joinery products made of sapwood and false heartwood beech.

New and Unforeseen Crystal Growth Processes for a Metal Oxide.

The synthesis of corundum (α-Al2O3) via a layered Al2O3-MoO3 system was directly observed for the first time. This revealed a new crystal growth process with three key features: (1) the formation of an Al2(MoO4)3 intermediate layer through a solid-solid interaction in the temperature range of ∼705-860 °C; (2) the melting of the Al2(MoO4)3 layer between approximately 870 and 890 °C; and (3) the decomposition of Al2(MoO4)3 to corundum between 950 and 1100 °C. This molten intermediate decomposition (MIND) mechanism produced corundum, which was light bluish-gray in color and was defined in CIE (L* a* b*) color space as L* = 76.65, a* = -1.09, and b* = -6.20. The reagents used in this study were the same as those used in MoO3 flux growth studies on the synthesis of corundum, therefore demonstrating that the previous work only gave a superficial treatment of the mechanism of formation.

Revisiting the question “Why is the sky blue?”

Abstract. The common answer to the question “Why is the sky blue?” is usually Rayleigh scattering. In 1953 Edward Hulburt demonstrated that Rayleigh scattering accounts for 1/3 and ozone absorption for 2/3 of the blue colour of the zenith sky at sunset. In this study, an approach to quantify the contribution of ozone to the blue colour of the sky for different viewing geometries is implemented using the radiative transfer model SCIATRAN and the CIE (International Commission on Illumination) XYZ 1931 colour system. The influence of ozone on the blue colour of the sky is calculated for solar zenith angles of 10–90∘ and a wide range of viewing geometries. For small solar zenith angles, the influence of ozone on the blue colour of the sky is minor, as expected. However, the effect of ozone increases with increasing solar zenith angle. The calculations for the Sun at the horizon confirm Hulburt's estimation with remarkably good agreement. More stratospheric aerosols reduce the ozone contribution at and near the zenith for the Sun at the horizon. The exact contribution of ozone depends strongly on the assumed total ozone column. The calculations also show that the contribution of ozone increases with increasing viewing zenith angle and total ozone column. Variations in surface albedo as well as full treatment of polarised radiative transfer were found to have only minor effects on the contribution of ozone to the blue colour of the sky. Furthermore, with an observer at 10 km altitude an increase in the ozone influence can be seen.

183 Assessment of Textural Characteristics and Instrumental Color of Commercially Available Whole-Muscle Jerky-Style Pet Treats

Abstract Textural and instrumental color quantitative data of consumables is often kept confidential by manufacturers, making it limited and difficult to find. These data are also important for product development and further sensory analysis to understand preferences and acceptability of purchasers. Between January 2019 and September 2020, 7,200 pet food products were launched worldwide. With a wide variety of pet treat brands and product types on the market, differentiation is necessary from a consumer purchase experience and physical characteristic preference perspective. The objective was to collect quantitative data on textural characteristics and instrumental color of whole-muscle jerky treats from 4 commercially available brands. Four whole muscle jerky treat brands were purchased for analyses: brand 1, brand 2, brand 3, and brand 4. Textural analyses included a three-point bend test for hardness (g), the maximum force required to break the sample; flexibility (mm), the displacement of the sample until it fractures; and stiffness (g per mm), resistance to bending; and the Warner-Bratzler test assessed firmness (g), the maximum force needed to shear the sample; and toughness (g per second), the peak positive area under the curve. Instrumental color was measured using a HunterLab MiniScan EZ spectrophotometer in terms CIE color space, L*, representing lightness on a range from black to white; a*, denoting redness ranging from green to red; and b*, representing yellowness ranging from blue to yellow. Data were analyzed as a 1-way ANOVA using the GLIMMIX procedure of SAS ver. 9.4, and least square means were separated using the PDIFF option. Brand 2 was significantly harder (P &amp;lt; 0.0001), and stiffer (P &amp;lt; 0.0001) than the rest of the brands, and Brand 4 was the most flexible (P = 0.0006). Brand 4 treats were the darkest, and brands 1 and 3 were among the brightest (P &amp;lt; 0.0001), although brand 3 was still similar to brand 2. Brand 3 expressed the greatest redness values and brand 4 the least (P &amp;lt; 0.0001). Brands 1, 2, and 3 were similar in yellowness and were all more yellow than brand 4 (P &amp;lt; 0.0001). When manufacturing pet treats, the goal is to achieve an appropriate texture, not soft enough to compromise its durability and integrity during manufacturing, packing, transportation, and retail, but soft enough to appeal to pet owners and dogs alike. These data will aid product developers by providing quantitative information that will eventually lead to corollary consumer sensory panel analysis to determine pet owner preferences and acceptability.

Colorimetric detection of glucose with smartphone-coupled µPADs: harnessing machine learning algorithms in variable lighting environments

Recent advances in microfluidic paper-based analytical devices (µPADs) have shown immense potential for point-of-care testing (POCT) in resource-constrained settings, especially for monitoring glucose levels in patients with diabetes. However, the practical adoption of smartphone-coupled µPADs has been limited due to the variability in ambient lighting conditions, which affects the colorimetric detection. In this study, we have developed a machine learning-based algorithm together with a flash/no-flash technic, adaptable to various µPADs and capable of accurately monitoring plasma glucose levels across a wide range (25 µM to 30 mM), addressing issues related to environmental illumination variations, and shooting angles.The algorithm is implemented in an Android application, Gluco estimator. It utilizes images captured by smartphones and incorporates intelligent feature engineering. The XYZ color space is adopted for device-independent analysis. KI and TMB color indicators are used to enhance resolution for low and high glucose concentrations, respectively. The EBC classifier, combined with a handcrafted feature set, exhibits outstanding performance, achieving an accuracy of 95% and 91% for TMB and KI, respectively. Additionally, multiple linear regression (MLR) yields high reliability among regression models, with R2 values of 0.95 at 0.25 µM to 3 mM and 0.97 at 3–30 mM. This work represents a significant stride toward realizing a portable, high-resolution, and reliable smartphone-coupled µPAD in uncontrolled environments.