A Comparison of Fresh Pork Colour Measurements by Using Four Commercial Handheld Devices

The objective of this study was to evaluate the performance of different low-cost instruments to measure pork colour in comparison to Minolta spectrophotometers and industry subjective standards. Canadian pork colour standards and commercial meat (252 loin chops and 46 tenderloins) were measured using two Minolta (CM 700D) spectrophotometers, four Nix sensors (two Nix Pro II and two Nix QC), and four Spectro devices (two Spectro 1 and two Spectro 1 Pro). Using Bland-Altman plots, all hand-held devices revealed similar performance on colour coordinates, except for the Nix Pro II, which had more variability on a* value, and Spectro 1 Pro on b* value, when compared to Minolta measurements. Low RSD values (< 5%) were obtained from repeated measurements on Canadian colour standards. The trend of colour coordinates on colour scores (0–6) were similar for all four commercial instruments, except for a* from Nix Pro and b* from Spectro 1. The correlation coefficients between subjective standards and colour coordinates from the Nix and Spectro devices were slightly higher than the Minolta spectrophotometers. Even though Nix and Spectro 1 series instruments generated different absolute colour coordinate values on meat samples, these pocket-size instruments presented great reliability to measure pork surface colour. However, operational limitations of the instruments, such as the internal calibration time between samples for the Spectro 1 series, should also be considered.

Differentiating Soils from Arable and Fallow Land Using Spectrometry

In this study, we analyse soil system responses—in particular, the colours of soils resulting from different types of land use (arable land and residential areas) caused by the construction of an ancient boundary rampart near a multilayer monument dating from between prehistory and the Middle Ages within the boundaries of the Bosporus Kingdom (Eastern Crimea)—in an area of modern and ancient (4th–2nd centuries BC) land use (Northwestern Crimea). These differences are of interest because they offer the chance to decipher different types of ancient land use and systems of land surveying, incorporating data from colour aerial photographs obtained with the help of unmanned aerial vehicles. Soil samples displaying different types of anthropogenic transformation were taken from the ancient boundary ramparts and adjacent land. The soil colour coordinates in the CIE L*a*b system were measured with the help of an AvaSpec-2048 spectrometer. Differences in colour coordinates were analysed using analysis of variance (NPMANOVA) based on the permutation test, the Kruskal–Wallis test, and the Mann–Whitney test, corrected according to multiple comparisons carried out as per the Bonferroni method. The results of this statistical analysis show that there are statistically significant differences in soil colour coordinates between samples collected on the ramparts and under various other types of land use. These differences are more pronounced in the samples characterised by the agrogenic transformation of soil. This makes it possible to use remote sensing data to detect traces of ancient boundary ramparts, even if the ramparts are partially destroyed by ploughing.

Correlation between CIELAB colour coordinates and malondialdehyde eqiuvalents in sausage with paprika stored under refrigerated conditions

Sensory properties of foods mainly affect purchasing decisions. In case of sausages, deterioration of pigments of meat and spices cause discolouration, while lipid oxidation leads to the formation of off-odours, and these two processes are connected. Lipid oxidation promotes the conversion of pigments, while the formation of metmyoglobin accelerates lipid oxidation. The scope of the study was to investigate the relationship between the amount of malondialdehyde equivalents (MDA) and CIELAB colour coordinates in a Hungarian sausage with paprika, sliced and stored under refrigerated conditions for 10 weeks. We detected negative correlation (P < 0.001) between the MDA-level and a* and b*; and positive correlation (P < 0.001) between the MDA-level and L*. The observed correlation between MDA level and colour coordinates supports the assumption that the oxidation of lipids and pigments are interrelated in the case of sausage with paprika.

Sugar and no sugar added fruit microalgae-enriched jams: a study about their physicochemical, rheological, and textural properties

Jams are preparations of fruits whose main preserving agent is sugar. Due to this, health concerns of consumers have resulted in a sugar reduction, and its replacement using alternative sweeteners and introducing new ingredients enhancing nutritional properties. In this study, four types of fruits jams (plum, strawberry, apple, and peach), with or without sugar, were prepared using two microalgae biomass, Arthrospira platensis (Spirulina) and Chlorella vulgaris, and Dunaliella salina extract as ingredients at different mix levels of concentrations, 0.10%–0.10%–0.05% respectively, for plum; 0.04%–0.00%–0.01 respectively, for strawberry; 0.06%–0.04%–0.00% respectively, for apple and 0.00%–0.01%–0.04% respectively, for peach. Physicochemical, rheological, and textural parameters were evaluated. Substitution of sugar/fructose syrup in the jam’s preparation caused changes in pH values, solid soluble content, and rheological and textural properties compared to sugar jams. Using sugar or sweeteners as isomalt, stevia and sucralose and microalgae biomass or extract showed significant changes in colour coordinates, however, these differences were not perceptible by the human eye. Jams containing microalgae biomass-extract showed higher G', G'', G*, and η* values than their corresponding control samples. All the jams presented weak-gel characteristics, distinguishing fruit jams. However, the results of weak-gel model analysis suggest that the influence of the different ingredients in the food system depends not only on their concentration but also on the interactions in the gel structure. Strawberry and apple jams showed no significant differences between microalgae biomass-extract samples and control samples, for both sugar and no sugar added jams being the best-obtained samples.

Measurement of colour coordinates of LEDs used in the automotive exterior lighting

Article deals with dichromatic white light-emitting diode (LED’s) color coordinates used in automotive exterior lighting. This article also describes basic white automotive LED functionality and basic physical processes that create white light of these LEDs. It focuses on measuring color coordinates of white automotive LEDs with different temperature of LED and how the LED’s color depends on LED’s temperature. The article is comparing very important datasheet information of LED producers and values measured in the laboratory at university. The article contains statistical results of measurements and graphical representation of measured values and declared color bins which are very important for producers of headlamps for automotive companies.

Organoboron compounds constructed through the tautomerization of 1H-indole to 3H-indole for red OLEDs

3H-Indole-containing emitters able to realize red fluorescent OLEDs possessing concurrently high efficiencies and good colour coordinates were synthesized through a tautomerization reaction.

Effect of Bleaching with Strawberry Extract and Hydrogen Peroxide on Colour Change, Surface Morphology and Micro-Shear Bond Strength of Resin Composite to Enamel Surface

Introduction: The search to replace the chemical bleaching agent namely the Hydrogen Peroxide (HP) with a natural substance to whiten the discoloured tooth is a need of the hour, due to the severe roughing and compromised bonding of resin composite to enamel surface by this agent. Aim: To evaluate and compare the colour and surface changes in enamel surface, and the micro-shear bond strength of resin composite to enamel following bleaching with 35% HP and 2% Strawberry Extract (SE). Materials and Methods: In this in-vitro study, 30 bovine maxillary central incisors were decoronated and allocated randomly to two groups: group 1 (negative control) (n=15) and group 2 (experimental) (n=15). To evaluate the bleaching efficacy, group 2 specimens were experimentally stained with tea. Baseline colour coordinates (pre-bleach values) (L*, a*, b*) (∆E) were recorded. The crowns were sectioned to obtain four equal parts to obtain 60 specimens and these were allotted randomly to 4 subgroups a, b, c, d (n=15 each) based on the bleaching protocol. Subgroup a, Hydrogen Peroxide (HP). subgroup b, Strawberry Extract (SE); subgroup c, HP+SE (HPS); subgroup d, HP/P (HP/ Proanthocyanidin). Following bleaching, colour coordinates (post-bleach values) (L*, a*, b*) (∆E) were measured as mentioned before. Qualitative analysis of the surface (n=2) for each group was performed using scanning electron microscopy. Micro-shear bond strength of resin composite to the treated specimens (n=13) was determined using universal testing machine at a crosshead speed of 1 mm/min. Kruskal-Wallis one-way Analysis of Variance (ANOVA) was used to calculate the p-value and Post-Hoc Tukey Honest significant Test (HSD) was used to identify the significant groups, p-value (<0.05). Results: All the post-bleach specimens showed significantly higher mean ∆E (more whiter) values compared to their respective pre-bleach specimens (baseline values) (p-value -<0.05). Among the post-bleach groups, highest ∆E values (more whiter) were observed in subgroup 2c(HPS) (p-value=0.029). Similarly minimal morphological surface irregularities were observed in HPS. Group 1 (negative control) had the highest micro-shear bond strength compared to the experimental groups (group 2). Significantly, higher micro-shear bond strength was observed in subgroups 2b,c,d (SE, HPS, HPP) compared to subgroup 2a(HP) (p-value <0.001). Conclusion: SE alone or in combination with HP is an efficient and effective dental bleaching agent.

Correlation of the colour of straw fuel pellets to the compressive properties

The aim of the manuscript was the evaluation of the compressive properties of straw pellets in relation to the colour differences between them. Modulus of elasticity and failure strength of the pellets at the compression were determined. A testing machine Andilog Stentor 1000 (Andilog Technologies, Vitrolles, France) was employed for uniaxial compression tests. L*, a*, b* colour coordinates of CIE LAB 3D colour space were used for the characterization of the pellet's colour. Two sorts of pellets were measured: made from wheat straw and made from the mixed wheat and barley straw. Samples were measured by a spectrophotometer 3NH YS3020 and computed as the mean of twenty samples. The correlation of the pellet colour with the mechanical properties, mainly modulus of elasticity and failure strength of the pellets at the compression were realized to obtain a relation of the deformation process to the pellet's colour of different sorts of pellets.

Influence of the Varnishing "Surface" Coverage on Optical Print Characteristics

Varnishing is often used to protect or decorate the print, but it can also influence the print’s colour appearance. Therefore, varnishing should enhance the print role, while colour change should be kept as low as possible. The aim of this paper is to evaluate inkjet UV LED varnishing by estimating optical print characteristics. Prepared offset prints were UV LED varnished in different surface coverage values (SCV) with a matte and gloss finish. The prints were evaluated by measuring gloss and colour coordinates. Secondly, varnishing was performed in a different SCV, which enabled assessing the optimal SCV, i.e. the most cost-efficient varnishing. The printing process was conducted in a standardized and controlled laboratory environment, regulated via the ISO 12647-2:2013 norm to ensure that the black colour was reproduced in the standard tolerance. The results showed that the colour difference is negligible (stays in the ISO tolerances), regardless of the varnishing SCV. On the other hand, the optimal printing gloss is at the SCV of 100%.

Colorimetric changes of waterbased flexographic ink printed on hemp-based papers exposed to artificial ageing

The objective of the research was to investigate colorimetric changes of the waterbased flexographic ink printed on hemp-based papers subjected to artificial ageing. Three types of commercially available hemp office papers were used as printing substrate and by Esiproof instrument were printed manually in full tone with process waterbased flexographic inks. Both, papers and prints were exposed to artificial ageing in the Suntest XLS+ test chamber according ASTM D 6789-2 standard. The L∗, a∗, b∗ colour coordinates were measured and ΔE00 colour difference was calculated for different stages of light exposure in order to determine the change from the original color value. In total exposure time was 96 h. The results have shown how the paper optical stability is dependent upon manufacturing process and that bleached hemp fibers provides better optical stability of papers than unbleached hemp fibers. Further, stability of prints made on hemp-based papers is for the most part defined by ink color, while the impact of the printing substrate is less pronounced. Generally, it was noticed how the most stable among prints were prints covered with the black ink, while prints with the yellow ink had the greatest changes in color under the influence of light.