A Comparison of Two Different Light Booths for Measuring Color Difference of Metameric Pairs

A standardized source of light is essential for visual color assessments, which is why lighting booths were developed. For the best results in visual assessment, it is important to consider the right choice of light source, the right viewing conditions, and the variability of the viewer. To date, many light booth technologies have been introduced to meet user demands. Since most of the light sources on the market are characterized by the designer or manufacturer, the resulting variations from booth-to-booth remain. In this study, we compared the performance of two standard light booths to assess the color difference of eleven metameric pairs. In this study, we checked an earlier technology-based light booth that is still used in the textile industry and contains illuminant A (Tungsten lamp) with CCT 2700 K, TL84 (tri-band fluorescent tube) with CCT 4000 K, and simulator D65 (CCT 6500 K) with a different light booth whose original light sources have been replaced by currently available LED retro kits from equivalent CCTs. As an inexperienced customer or industrial user, our question was, how important is this replacement? The results revealed that two different standard lighting technologies with similar CCTs cannot reproduce the same estimates because the light sources produced different SPDs. It is illustrating that caution is necessary when comparing results obtained from two different light booths containing light sources with similar CCTs but different SPDs. This comparative study suggested that the variability of the light sources’ SPDs or the observer or the sample should be modeled considering light booth’s technology to estimate its contribution to the overall variability. The close relationship between perceived and CAM02-UCS suggests that if both booths are used after the light sources have been calibrated, a formula based on color appearance models must be used to predict color appearance. To obtain better agreement between perceived and calculated color difference, one must need to avoid light booths with nominally white light sources.

Adaptive auditory brightness perception

Perception adapts to the properties of prior stimulation, as illustrated by phenomena such as visual color constancy or speech context effects. In the auditory domain, only little is known about adaptive processes when it comes to the attribute of auditory brightness. Here, we report an experiment that tests whether listeners adapt to spectral colorations imposed on naturalistic music and speech excerpts. Our results indicate consistent contrastive adaptation of auditory brightness judgments on a trial-by-trial basis. The pattern of results suggests that these effects tend to grow with an increase in the duration of the adaptor context but level off after around 8 trials of 2 s duration. A simple model of the response criterion yields a correlation of r = .97 with the measured data and corroborates the notion that brightness perception adapts on timescales that fall in the range of auditory short-term memory. Effects turn out to be similar for spectral filtering based on linear spectral filter slopes and filtering based on a measured transfer function from a commercially available hearing device. Overall, our findings demonstrate the adaptivity of auditory brightness perception under realistic acoustical conditions.

Feeding, Muscle and Packaging Effects on Lipid Oxidation and Color of Avileña Negra-Ibérica Beef

In order to increase the economic profitability of Avileña-Negra Ibérica beef production, the inclusion of corn silage in total mixed rations was proposed during the fattening period. Twenty-four Avileña-Negra Ibérica breed entire young bulls were used to evaluate the effects of two feeding systems—concentrate (CON) and corn silage (SIL)—and two packaging systems—vacuum (VAC) and modified atmosphere (MAP)—on the lipid oxidation, color evolution and visual color acceptability of meat throughout display with either oxygen-permeable film (FILM) or modified atmosphere (MAP). Two muscles were assessed: Longissimus thoracis (LT) and Semitendinosus (ST). Meat from SIL-fed animals had higher TBA values than CON-fed animals after 7 days in MAP packaging. Lipid oxidation was prevented more effectively by VAC packaging than MAP. Display time highly influenced lipid oxidation, since oxidation rates were lower with VAC than MAP packaging. After 14 days of display in MAP, the LT from CON was lighter than the ST. Meat discoloration after 7 days of display was significantly different between packaging systems. Vacuum-packaged meat kept the same color throughout the storage time. Visual color acceptability for the LT was higher throughout display than for the ST. Samples from the MAP were well accepted by consumers, especially the meat from the SIL group. Alternatively, feeding with corn silage could be used for this type of animals without affecting important aspects of meat quality.

Karakteristik Minyak Atsiri Daun Melaleuca leucadendra L. dari Empat Lokasi yang Berbeda Di Kabupaten Paser Kalimantan Timur

Cajuput oil, which comes from the Melaleuca, is one of the NTFPs that is widely used for various health or pharmaceutical products so that it is a product that is in great demand. This study aimed to measure the yield and analyze the physical properties of M. leucadendra L. essential oil which comes from Paser, East Kalimantan. Samples were taken from 4 different locations, namely Rantau Panjang, Jone, Padang Pangrapat and Pondong Baru. Essential oils were obtained from distillation process using the water and steam method. The physical characteristics of essential oils were analyzed including visual color and refractive index using a hand refractometer. The results of M. leucadendra L. oil distillation from 4 locations, namely Rantau Panjang, Jone, Padang Pangrapat and Pondong Baru. showed the various yields, among others, 0.030%, 0.066%, 0.104% and 0.031%. The color of the essential oil observed also varied from yellow to orange and the refractive index range obtained was 1,429-1,450. The results of this study have the potential as a new source of cajuput oil originating from East Kalimantan, however further research is needed to find out about the appropriate distillation technique in order to increase the yield of M. leucadendra essential oil.

Repackaging Nitrite-embedded Dark-Cutting Steak in Aerobic Polyvinyl Chloride Film Decrease Surface Redness

Theoverall goal was to evaluate the effects of repackaging nitrite-embeddeddark-cutting steaks in polyvinyl chloride (PVC) film on surface color.Dark-cutting beef strip loins (n = 8; pH = 6.39) and USDA Low Choice beef striploins (normal-pH, n = 6) were selected at a commercial packing plant.Dark-cutting loins were bisected and randomly assigned to nonenhanceddark-cutting and enhanced dark-cutting with glucono delta-lactone and rosemarytreatments. Normal-pH and nonenhanced dark-cutting steaks were vacuum packaged (VP)and served as controls, while enhanced dark-cutting steaks were packed innitrite-embedded packaging (NP). Steaks from nonenhanced normal-pH in VP, non-enhanceddark-cutting-VP, and enhanced dark-cutting-NP loins were randomly assigned to3, 6, or 9 d of dark storage. Following dark storage, steaks were repackaged inPVC and displayed for 6 d. The instrumental color, visual color, and aerobicplate count were evaluated for all steaks.  Enhanced dark-cutting steaks in nitritepackaging increased (P < 0.05) a* values and nitric oxide myoglobincontent during 24 h of dark storage. Enhanced dark-cutting steaks packaged inNP had greater a* and L* values (P < 0.05) than nonenhanced dark-cutting-VP steaks during darkstorage. Upon repackaging the enhanced dark-cutting steaks from nitritepackaging, nitric oxide myoglobin decreased (P < 0.05) during the first 12 h of display. Loss of nitric oxidemyoglobin corresponds with a darker red appearance, increased surfacediscoloration, and decreased a*values. There were no differences (P> 0.05) in aerobic plate count between enhanced dark-cutting-NP and non-enhanceddark cutting VP steaks during 9 days of dark storage. In conclusion, NPimproved surface redness; however, repackaging enhanced dark-cutting from NP steaksin PVC decreased color stability and redness of dark-cutting beef. 

Detection of Lysyl Oxidase Activity in Tumor Extracellular Matrix Using Peptide-Functionalized Gold Nanoprobes

High LOX levels in the tumor microenvironment causes the cross-linking of extracellular matrix components and increases the stiffness of tumor tissue. Thus, LOX plays an important role in tumorigenesis and in lowering the tumor response to anticancer drugs. Despite comprehensive efforts to identify the roles of LOX in the tumor microenvironment, sensitive and accurate detection methods have not yet been established. Here, we suggest the use of gold nanoparticles functionalized with LOX-sensitive peptides (LS-AuNPs) that aggregate upon exposure to LOX, resulting in a visual color change. LOX-sensitive peptides (LS-peptides) contain lysine residues that are converted to allysine in the presence of LOX, which is highly reactive and binds to adjacent allysine, resulting in the aggregation of the AuNPs. We demonstrated that the synthesized LS-AuNPs are capable of detecting LOX sensitively, specifically both in vitro and in the tissue extract. Moreover, the suggested LS-AuNP-based assay is more sensitive than commonly employed assays or commercially available kits. Therefore, the LS-AuNPs developed in this study can be used to detect LOX levels and can be further used to predict the stiffness or the anticancer drug resistance of the tumor.

Impact of Packaging Film and Beef Trimmings on Ground Beef Shelf Life

Fresh beef storage in the retail setting can be presented in a variety of packaging methods, and identifying an alternative such as vacuum packaging to current traditional methods could potentially increase shelf life and reduce meat waste. The objective of this study was to identify the influence of packaging film and lean trimming sources on fresh ground beef surface color during a simulated retail display period. There were no differences (p > 0.05) in surface color redness (a*), yellowness (b*), chroma, or hue angle regardless of packaging film or lean trimmings. However, thiobarbituric acid reactive substances (TBARS) were greater (p < 0.05) for packages containing a greater percentage of CULL beef trimmings regardless of packaging film. In addition, pH values of ground beef packages did not differ (p > 0.05) among packaging film or lean trimming blends. Visual color did not differ (p > 0.05) throughout the simulated retail display period regardless of beef trimmings or packaging film. Microbial spoilage organisms were greater (p < 0.05) after the simulated display period. These results suggest that ground beef presented in a simulated retail setting using an alternative packaging platform, such as vacuum packaging, is plausible.