Greater Color Stability Research Articles

The Application of the Ultrasound Technique in the Production of Rosé and Red Wines

The application of the ultrasound technique (US) in the production of rosé and red wines has demonstrated that the aromatic composition of rose wine can be affected and that it contributes to increasing the color of red wines without increasing the extraction of astringent tannins. The ultrasound treatment has favored the extraction of anthocyanins, which has had an impact on the increase in color density (C.D.) and has allowed greater color stability over time. Moreover, significant differences have been found between the two US systems applied, with continuous treatment being more effective in the extraction of phenolic compounds than pulsed treatment. The application system of the US also affects the aromatic composition of the wines. These results are of interest, as some esters have been described as important odorants in wines.

The Effect of Different Immersion Media, Polymerization Modes, and Brushing on the Color Stability of Different Composite Resins.

This in vitro study investigated color stability of two photo-polymerized nano-filled and nano-hybrid composite resins in different polymerization modes immersed in different staining solutions before and after brushing. Disc-shaped specimens (n = 120) were prepared from two composite resins based on filler particle size: nano-filled (Filtek Z350, shade A1, 3M ESPE) and nano-hybrid (Spectra ST-HV, shade A1, Dentsply Sirona) composite resins (n = 60 per composite type). Specimens of each resin type were photopolymerized using the following polymerization modes: LED conventional, ramp, and pulse (n = 20 specimens per resin type and LED mode). After preparation, baseline color of the specimens was evaluated using a spectrophotometer (Easyshade V, VITA), and color change was evaluated using the CIE L*a*b* formula. Specimens were soaked in distilled water for 4 weeks in separate containers. The specimens from each polymerization-mode group were separated into two groups of 10 specimens; one group was stored in tea and the other group was stored in cola, each 1 hour daily for 4 weeks. After 4 weeks, the color was measured again. The specimens were brushed for 2 minutes under 200-g weight using an electronically powered toothbrush on the polymerized side of the specimen. The color was reevaluated immediately after brushing. Color-difference data (ΔE) between groups were analyzed by one-way analysis of variance for main comparison and by independent t test for color change after brushing. Nano-filled composite resin was more color-stable than nano-hybrid composite resin (P < .001), regardless of the staining media. For both composite resin types, the conventional polymerization method produced a more color-stable result (P < .0001). ΔE after brushing was reduced significantly (P < .0001). Both staining solutions have significant effects on color change, with tea staining more than cola (P < .0001). Nanofilled composite resin had greater color stability than nano-hybrid composite resin after immersion in staining solutions. Polymerization mode influences the color stability of both composite resin types. Int J Periodontics Restorative Dent 2023;43:247-255. doi: 10.11607/prd.6427.

Effect of Home Bleaching on the Optical Properties and Surface Roughness of Novel Aesthetic Dental Ceramics

The optical qualities of cutting-edge aesthetic dental ceramics are crucial for great aesthetics and may be impacted by various bleaching methods. The objectives of this study were to evaluate how home bleaching affected the translucency parameter (TP), contrast ratio (CR), total color difference (ΔE), and surface roughness (Ra) of various aesthetic dental ceramics, including innovative ultra-translucent zirconia. The three varieties of ceramics that were tested—IPS e.max-Press (IPS); classic zirconia with feldspathic layering (LZr); and translucent zirconia (TZr)—were each represented by seven samples. The samples were bleached at home using 15% carbamide peroxide for six hours a day for seven days. Each specimen’s pre- and post-bleaching CIE L*a*b* values were measured using a spectrophotometer, and the TP, CR, and ΔE were determined. Ra values were measured via 3D profilometry. In comparison to the pre-stage results, statistical analysis showed a significant decrease in TP and increase in CR for LZr and TZr in the post-stage (p &lt; 0.05), but not for IPS (p = 0.398). The results also showed substantial variations in ΔE for the three ceramics (p = 0.020). Ra readings during the post-stage were noticeably greater than those at the pre-stage (p = 0.018). Home bleaching had an impact on the optical characteristics and surface texture of the dental ceramics. Additionally, IPS had greater color stability than LZr and TZr.

An Evaluation of the Colour Stability and Surface Roughness of High Translucency Zirconia Dental Ceramic after Immersion in Different Acidic Media: An In-vitro Study

Introduction: Demand for increasingly appealing metal-free ceramic restorations drives research. With its exceptional mechanical and biological properties, zirconia crown outperforms other traditional ceramic materials. With outstanding mechanical and biological qualities, zirconia has several therapeutic applications. Temperature, environment, diet, and smoking habits all affect colour and surface roughness of dental restorations. Aim: To investigate the colour stability and surface roughness of high translucency monolithic zirconia following immersion in various acidic solutions. Materials and Methods: This in-vitro study was conducted at Yenepoya Dental College, Mangalore, Karnataka, India. Duration of the study was 6 months, from December 2019 to June 2020. Thirty rectangular samples from a CAD (computer-aided Design)/ Computer Aided Manufacturing (CAM) machined Zirconia blank with 10x8x1 mm dimensions was sintered at 1350°C, tested for colour stability (E) and surface roughness prior to immersion (R). Classified into Groups CO (coffee), TO (tobacco) and CA (citric acid medium). Colour stability and surface roughness were re-evaluated post immersion on all samples using spectrophotometers and profilometer respectively. A significant difference in surface roughness and colour stability between the test groups was assessed using the paired-t test. The data was analysed using Statistical Package for Social Sciences (SPSS) version 24.0. Results: Colour stability and surface roughness variations between the baseline value and three groups were found to be unaltered by different acidic media. The intergroup comparison of spectrophotometric analysis between the three groups had a standard deviation of 0.422 for citric acid medium, 0.316 for Coffee medium and 0.422 for Tobacco medium with an overall p-value of 0.804. The intergroup comparison of profilometric analysis had a standard deviation of 0.316 for Citric acid medium, 0.00 for Coffee medium and 0.00 for Tobacco medium with an overall p-value of 0.381. The paired-t-test study showed that immersion in different acidic media had little effect on surface roughness of samples with a p-value of 0.343 but it was under clinically acceptable range. Conclusion: According to the present study, high translucency monolithic zirconia had greater colour stability when treated with citric acid, followed by tobacco and then with coffee media, whereas, zirconia in coffee media had greater surface roughness, followed by tobacco, and then with citric acid media. However, both the results were clinically acceptable, indicating a 10 year lifespan when properly glazed.

The Effect of Loading Time on Color Stability of Various Restorative Materials Bonded to Silver Diamine Fluoride-Treated Demineralized Dentin.

AimTo investigate the effect of immediate versus one week later loading time on color stability of resin-based composite (RBC), resin-modified glass ionomer cement (RMGIC) and glass ionomer cement (GIC) restorative materials bonded to silver diamine fluoride (SDF)-treated demineralized dentin.Materials and MethodsNinety extracted premolars were randomly assigned to the following groups (n = 30 each): group-I (loaded with RBCs), group-II (loaded with RMGIC), and group-III (loaded with GIC). Each group was divided randomly into the following subgroups (n = 10): subgroup-A (control specimens) consisted of sound dentin and the restorative material was immediately loaded; subgroup-B consisted of demineralized dentin, underwent a SDF treatment and the restorative material was immediately loaded; subgroup-C consisted of demineralized dentin, underwent a SDF treatment and the restorative material was loaded 1 week later. The color difference (ΔE) and visual color changes (L*a*b*) of each specimen were calculated using a spectrophotometer. Data were analyzed using one-way ANOVA and post hoc Tukey’s tests to compare the ΔE values and a paired t test to compare the mean of L* a* b* coordinates.ResultsThe highest color stability was observed for GIC, followed by RMGIC, and the lowest color stability was observed for the RBC group. Significant differences within groups were noted in RBC and RMGIC (p < 0.001). Regarding the loading time of the restorative material, in RBCs, a significantly lower ΔE value was observed in the delayed loading group than in the immediate loading group (p = 0.035). In the RMGIC and GIC groups, there were no significant differences.ConclusionDelaying the loading time of the restorative material for 1 week following the application of SDF resulted in greater color stability than that of immediate loading. The caries arresting potential of SDF was revealed by the dark staining, which could be improved with the subsequent delayed restoration.

Impact of Retail Case Type and Lighting Intensity on Instrumental Color Traits of Ground Beef Patties

Abstract The objective of this study was to determine the influence of retail case type and lighting intensity on color stability of ground beef patties. Ground 80:20 beef was procured from a local retail establishment between 7 and 10 d from the box date and ground through a 9.5 mm grinder plate, then formed into 150.25 g patties. Patties were then individually packaged in PVC-overwrap packages and randomly assigned into one of four treatments: open, multideck cases with 3000 K lighting (OPEN3000), open, 3500 K lighting (OPEN3500), enclosed, multideck cases with doors with 3000 K lighting (DOOR3000), and enclosed multideck at 3500 K lighting (DOOR3500). Patties were displayed for 7 d and instrumental color values (CIE L*, a*, and b*) were taken every 24 h. Data were analyzed as a 2 × 2 factorial arrangement with repeated measures, with case type, lighting intensity, and their interaction serving as fixed effects. Patties in DOOR cases possessed greater L* values (P &amp;lt; 0.05) than OPEN cases on d 3 of display. A similar trend existed for a*, where DOOR patties were redder (P &amp;lt; 0.05) than OPEN patties from d 2 to the end of display, and b* values were higher (P &amp;lt; 0.05) in DOOR cases from d 1 to d 4 of display. Patties from the DOOR cases also possessed increased chroma values (P &amp;lt; 0.05) from d 1 to 6 of display, and decreased (indicating more red) hue angle values from d 3 to the end of display. No differences were observed between lighting intensity for any trait evaluated (P ≥ 0.293). These results indicate patties placed in enclosed retail cases with doors are lighter, redder, and more intense in color during display compared to traditional open-front cases, which indicates greater color stability.

Effect of different placement techniques on color stability and surface roughness of resin composites

Abstract Introduction Longevity and clinical success of dental restorations can be influenced by many factors during the restorative procedures. Objective This study aimed to evaluate the influence of different placement techniques on color stability and surface roughness of two resin composites. Material and method The groups of specimens (n=10) were divided according to resin composite (FiltekTM Z250 XT and FiltekTM Z350 XT) and placement technique: Mylar strip, spatula, dry brush, modeling liquid, and surface sealant. Color stability and surface roughness were accessed using a spectrophotometer (CIELab color space) and a rugosimeter (standard cutoff of 0.8 mm), respectively, after water storage. Subsequently, the specimens were immersed in coffee for 48 h and final color was measured. The data were analyzed using ANOVA and the Tukey’s post hoc test (α=5%) and the correlation between surface roughness (Ra) and color change (∆Eab) was assessed using the Pearson’s correlation coefficient. Result The different placement techniques influenced Ra and ∆Eab on both resin composites. The groups treated with surface sealant showed greater difference in ∆Eab for both resin composites. The FiltekTM Z250 XT resin showed greater color stability compared with the FiltekTM Z350 XT resin regardless of the placement technique used. Ra of each placement technique was similar among the resin composites except for the FiltekTM Z350 XT modeling liquid group, which presented lower Ra values compared with those of FiltekTM Z250 XT. A correlation between Ra and staining was identified (p=0.268). Conclusion Color stability and Ra are influenced by different placement techniques.

Influence of sequential inoculum of Starmerella bacillaris and Saccharomyces cerevisiae on flavonoid composition of monovarietal Sangiovese wines.

The selection of Starmerella bacillaris strains to be used with Saccharomyces cerevisiae as mixed cultures has been recently suggested in order to produce wines containing lower ethanol and higher glycerol concentrations and to promote fructose degradation due to their fructophilic character. However, studies about effects of such mixed starter cultures on phenolic compounds, which are responsible for the colour and health-enhancing properties in red wines, are currently lacking. Therefore, in this work, the influence of sequential inoculated fermentation (SIF) with Starm. bacillaris and S. cerevisiae on phenolic content of monovarietal Sangiovese wine was evaluated by fermentations at laboratory scale. Axenic fermentations (AXFs) with S. cerevisiae were performed as control. S. cerevisiae attained higher cell densities in AXF compared with SIF. The experimental wines obtained by SIF showed significant lower ethanol and higher glycerol concentrations, whereas no significant difference was detected in colour intensity. The total phenol index reached significantly lower values in SIF. Furthermore, the wines produced by SIF contained higher concentrations of vitisin A that has a greater colour stability than the anthocyanin monomer. Finally, a lower content of both free anthocyanins and flavan-3-ols, key compounds for wine quality possessing also health-enhancing properties, was found in wines obtained by SIF. On the contrary, no significant difference was detected on flavonol concentration between SIF and AXF. This study highlighted that the use of sequential inoculum of Starm. bacillaris and S. cerevisiae can contribute to increasing the colour stability of red wines, even if at the expense of compounds with health properties.

Investigation of muscle-specific beef color stability at different ultimate pHs.

ObjectiveThis study was aimed to investigate the muscle-specific beef color stability at normal and high ultimate pHs.MethodsThe impact of muscle (Longissimus lumborum [LL] vs psoas major [PM]) and pH (normal ultimate pH [Np] vs high pH dark cutting beef [Hp]) on color stability, indicated by basic color traits, metmyoglobin reducing activity (MRA) and oxygen consumption (OC), as well as the lipid oxidation, were determined over 7 days of display at 4°C.ResultsHp-LL had the highest pH (6.92), followed by Hp-PM (6.01), Np-PM (5.76), and Np-LL (5.52). Hp-LL had increased (p<0.05) a*, chroma and % oxymyoglobin during display. Hp-LL also had the highest metmyoglobin (MMb) reducing activity and OC among all the samples, thus, the greatest color stability, although very dark throughout storage, with lowest values for lightness (L*) and yellowness (b*). Np-LL also exhibited relatively high color stability, as a result of its lower % MMb and OC and higher MRA than psoas muscle samples. The 0.2 unit difference of the pH between Hp and Np psoas muscle, resulted in the difference of the color intensity, not the color stability. Interestingly, high pH psoas muscle (Hp-PM) did not have better color stability than Np-PM, and in fact had lower color stability than even Np-LL. The similar level of OC and lipid oxidation cannot explain the difference in color stability between Hp-PM and Np-LL.ConclusionThe Hp does not always show better color stability compared with Np beef, which depends on the muscle type. The balance of MRA and OC is important to keep the color in great intensity and stability in the meantime.

Understanding the development of color and color stability of dark cutting beef based on mitochondrial proteomics

Label-free proteomics was applied to understand the color and color stability development of dark cutting beef (DC). The color traits of DC (pH = 6.86) and normal beef (pH = 5.49) were determined during 7 days of display. DC had a lower redness and greater color stability, which was attributed to its higher deoxy-myoglobin content, greater oxygen consumption, as well as higher metmyoglobin reducing activity and lower lipid oxidation. A total of 28 differentially expressed mitochondrial proteins (fold change >1.8) between the two groups were identified, with 21 proteins overexpressed in DC mainly involved in oxidative phosphorylation, generation of reducing equivalent, TCA cycle and chaperones. These enhance the level of mitochondrial respiration, the stability of reducing MetMb and myoglobin and mitochondria function, leading to color characteristics of DC. Moreover, Glutaryl-CoA dehydrogenase was for the first time reported to be significantly associated with color parameters and its direct relationship with meat color is worthy investigation.

Intelligent pH-sensitive indicator based on starch-cellulose and alizarin dye to track freshness of rainbow trout fillet.

A novel pH-sensitive indicator was prepared by incorporation of alizarin in a starch-cellulose paper to monitor the freshness of rainbow trout fillet. Water solubility of the fabricated indicator reduced by incorporation of alizarin, while the percentage of swelling didn't change. FTIR certified that alizarin was properly incorporated which was revealed by the formation of intermolecular hydrogen bonding in the cellulose-starch matrix. SEM and ultraviolet-visible spectrum results also demonstrated that alizarin had good compatibility with the components of the indicator. The alizarin-starch-cellulose indicator (ASC) had greater color efficiency from yellow to purple at pH 2-11 and greater color stability after two months of storage at 4 °C. It can be concluded that the color changes of ASC, from orange to reddish brown, were entirely corresponded with TVB-N contents of fish, which presents a satisfactory capability of developed indicator to identify the initiation of spoilage in the refrigerated fish fillet.

Characteristics of Hybrid Pigments Made from Alizarin Dye on a Mixed Oxide Host

This paper describes the fabrication of a new hybrid pigment made from 1,2-dihydroxyanthraquinone (alizarin) on a mixed oxide host (aluminum-magnesium hydroxycarbonate, LH). Various tools were applied to better understand the interactions between the organic (alizarin) and inorganic (LH) components, including ion mass spectroscopy (TOF-SIMS), 27-Aluminm solid-state nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). TOF-SIMS showed that modification of the LH had been successful and revealed the presence of characteristic ions C14H7O4Mg+ and C14H6O5Al−, suggesting interactions between the organic chromophore and both metal ions present in the mixed oxide host. Interactions were also observed between Al3+ ions and Alizarin molecules in 27Al NMR spectra, with a chemical shift detected in the case of the modified LH matrix. Any changes in color following reactions with Mg2+ and Al3+ ions were observed. Some of the physicochemical properties of alizarin, such as resistance to dissolution and color stability at elevated temperatures, were improved in comparison to the pure dye. This effect can be attributed to strong dye-LH interactions and the effective transformation of alizarin into an insoluble form. Moreover, the pigments exhibited higher thermal resistance and greater color stability in comparison to commercially available alizarin lakes (Alizarin Crimson).

Changes in the Sarcoplasmic Proteome of Beef Muscles with Differential Color Stability during Postmortem Aging

Beef color is a muscle-specific trait, and sarcoplasmic proteome influences muscle-specific variations in beef color stability. Postmortem aging influences the color and sarcoplasmic proteome of beef muscles. Nonetheless, muscle-specific changes in sarcoplasmic proteome of beef muscles with differential color stability during aging have not been characterized yet. Therefore, our objective was to examine the changes in the sarcoplasmic proteome of 3 differentially color stable muscles from beef hindquarters during postmortem aging. Longissimus lumborum (LL), psoas major (PM), and semitendinosus (ST) separated from 8 (n = 8) beef carcasses (24 h postmortem) were subjected to aging in vacuum packaging (2°C) for 0, 7, 14, and 21 d. On each aging day, steaks were fabricated, and allotted to refrigerated storage (2°C) under aerobic packaging. Samples for proteome analysis obtained during fabrication were frozen at –80°C. Instrumental color and metmyoglobin reducing activity were evaluated on d 0, 3, and 6 of storage. Sarcoplasmic proteome was analyzed, and differentially abundant proteins were identified using mass spectrometry. Color attributes and biochemical parameters were influenced by muscle source and aging (P &lt; 0.05); LL and ST had greater (P &lt; 0.05) surface redness than PM. Aging also influenced surface redness, with 7-d aged steaks demonstrating greatest values (P &lt; 0.05). Proteome analysis identified 135 protein spots differentially abundant (P &lt; 0.05) between the muscles and aging time points indicating muscle-specific changes during aging. The identified proteins included glycolytic enzymes, proteins associated with energy metabolism, antioxidant proteins, chaperones, and transport proteins. Overall, the glycolytic enzymes were more abundant (P &lt; 0.05) in color-stable muscles and at aging times with greater color stability, indicating that these proteins could be used as potential biomarkers for beef color.

Effect of denture cleansers and accelerated aging on the color stability of maxillofacial silicone: An in vitro study

Aim: Evaluate the effect of denture cleansers and accelerated aging on the color stability of a commercially available maxillofacial silicone. Materials and Methods: A commercially available maxillofacial silicone cosmesil M511 was mixed according to manufacturer's instruction with the incorporation of three pigments, namely, Burnt sienna, Hansa Yellow, and Alizarin red and packed into the stone molds prepared using metal dies according to ASTM standards. After processing, initial color measurement was carried out 72 h following processing using a spectrophotometer. The samples were later subjected to disinfection and accelerated aging for 504 h and 1008 h following which color measurement was carried out. The results were analyzed using one-way ANOVA and Tukey's multiple comparison test (P Results: There was a statistically significant difference in the color stability of the silicone samples pigmented with Hansa Yellow than with Burnt Sienna and Alizarin Red after disinfection and 504 h of accelerated aging. Silicone samples disinfected with Fittydent denture cleanser showed better color stability than samples disinfected with neutral soap. There was a statistically significant difference in the color stability of the samples after 1008 h of accelerated aging irrespective of pigmentation and disinfection method. Conclusions: Silicone samples pigmented with Hansa Yellow had greater color stability than the samples pigmented with other two pigments after disinfection and 504 h of accelerated aging. After 1008 h of aging, all samples showed poor color stability irrespective of pigmentation and disinfection method.

Callipyge genotypic effects on meat quality attributes and oxidation stability of ovine M. longissimus

The objective of this study was to evaluate the effects of callipyge (C) genotypes on quality attributes and oxidation stability of aged lamb loins. Only lambs possessing a wildtype maternal allele and a paternal callipyge allele (+/C) express a muscle hypertrophy phenotype. Seventeen lambs (7 months), consisting of all four possible callipyge genotypes (C/+, C/C, +/C and +/+), were harvested. Loins (M. longissimus thoracis) were separated from each carcass at 3days postmortem, cut into 3 sections, and randomly assigned into three aging periods (3, 6 and 9days). Genotype had no impact on proximate composition, mineral content, and pH of lamb loins (P>0.05). In terms of water-holding capacity, slightly increased purge/thaw loss of +/C lamb loins was observed (P<0.05), but cooking, drip and display weight losses were unaffected by callipyge genotype (P>0.05). The highest shear force was found at +/C lamb loins (P<0.05). +/C lamb loins showed initially less redness, but greater color stability during 7days of display compared to loins from the other genotypes. Heme iron content of +/C lamb loins was a significantly lower than the other genotypes. Genotype had no impact on lipid oxidation stability (P>0.05). Our results indicate similar quality attributes of lamb loins between non-callipyge phenotypes (C/C, C/+ and +/+) and suggest that callipyge lamb loins have superior color stability, while exhibiting lower tenderness compared to loins from non-callipyge phenotype lambs.

Effect of Ultrasound on the Stability of Turmeric Oleoresin Microencapsulated in Gelatin‐Collagen Matrices

AbstractThis study evaluated the effect of sonication on the stability of turmeric oleoresin microcapsules produced by spray and freeze‐drying using blends of gelatin‐collagen as encapsulating matrices. Samples prepared with different wall matrix formulations presented solubility between 82.7 and 86.9%, yield above 88% and encapsulation efficiency between 17.41 and 56.21%. The wall matrix composed of 2% gelatin and 28% collagen (C2G28), which presented the highest yield (94.7%) and good encapsulation efficiency (42.83%), was adopted to investigate the effects of ultrasound in the emulsification step (C2G28US), to compare the performance of spray and freeze‐drying, as well as to study stability of the microcapsules during storage under incident light. Ultrasound combined with spray drying resulted in the smallest particle size, according to SEM analyses and the highest curcumin retention (342.84 mg/g). Sonication also showed positive effects on product stability, with better curcumin color retention observed for spray‐dried microcapsules.Practical ApplicationsEncapsulation of turmeric oleoresin by spray drying in protein matrices composed of gelatin and collagen hydrolysate was enhanced by using ultrasound in the emulsification step, which resulted in the smallest particle size, higher curcumin retention and greater color stability under light incidence. The produced curcumin capsules may be used as a food supplement or as a natural dye.

Effect of forage and retail packaging types on meat quality of long-term chilled lamb loins1

The objectives of this study were to determine the effects of different forage regimes and modified atmosphere packaging (MAP) systems [high oxygen (HiOx-MAP): 80% O2 and 20% CO2; and CO2-MAP: 20% CO2 and 80% N2] on color and lipid oxidation stability and sensory attributes of long-term chilled lamb loins during retail display. Lambs (n = 124) were randomly assigned to several pasture-feeding regimes for 12 wk before slaughter. Some had ryegrass (n = 18), lucerne (n = 18), chicory (n = 19), plantain (n = 16), or red clover (Clover 12; n = 17) for all 12 wk. Some were assigned a regime of red clover for 11 wk and pasture for 1 wk (Clover 11; n = 18), with others on red clover for 9 wk and pasture for 3 wk (Clover 9; n = 18). After the lambs were slaughtered, the paired loins (M. longissimus dorsi) were excised at 24 h postmortem, vacuum-packed and stored at -1.5 °C for 9 wk. Cuts were then made from each loin and randomly allocated to either HiOx-MAP or CO2-MAP, and displayed for 7 d at 4 °C under light. Chemical attributes including lipid oxidation, surface color-reversing ability, oxygen consumption, and meat quality attributes (color stability and sensory characteristics) were determined. Among the different forage types, the loins from lambs finished on ryegrass appeared to have greater color stability and less lipid oxidation than the loins from lambs finished on other forage types (P < 0.05). On the other hand, the loins from lambs finished on lucerne had the least color and lipid oxidation stabilities and least color-reversing ability (P < 0.05). The loins from lambs finished on chicory had higher aroma and flavor scores than other pasture types in general (P < 0.05). HiOx-MAP negatively influenced meat quality attributes of lamb loins during display, as substantial increases in surface discoloration and lipid oxidation were observed, along with significant decreases in aroma and flavor during retail display compared with the loins in CO2-MAP. These results suggest that different forage types and packaging conditions could result in substantial impacts on meat quality attributes of long-term chilled lamb loins by affecting oxidation stability. Furthermore, the present study suggests that CO2-MAP could provide beneficial effects on the eating quality of long-term chilled lamb loins by suppressing oxidation-related defects during display without compromising the ability of blooming for meat display.

Color Stability and High Efficiency of White Phosphorescent Organic Light-Emitting Diodes with Suitable Position of Phosphorescent Red Emitter

We have demonstrated high-efficiency phosphorescent white organic light-emitting diodes (PHWOLEDs) using iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2] picolinate and iridium(III) bis[1-phenyl(quinolinato-N,C2')]acetylacetonate doped in N,N '-dicarbazolyl-3,5-benzene as a single-host system. As the position of the doped red emitter changed from near the anode to the cathode, the PHWOLED exhibited reduced exciton loss and greater color stability. The optimized PHWOLED exhibited a peak external quantum efficiency of 13.49%, a power efficiency of 20.59 lm/W, a current efficiency of 26.20 cd/A, and Commission Internationale de l'Eclairage coordinates of (0.37, 0.35). The red emitter near the cathode includes efficient triplet energy confinement in the emitting layers.

Degree of conversion and color stability of the light curing resin with new photoinitiator systems

Objectives This study investigated p-octyloxy-phenyl-phenyl iodonium hexafluoroantimonate (OPPI) as a photoinitiator, in combination with camphorquinone/amine photoinitiation systems, for use with di(meth)acrylate-based composite resins. The investigation determined if the inclusion of OPPI improved degree and rate of conversion, initial color and color stability of a representative composite resin dental material. Methods Camphorquinone (CQ) and OPPI were combined in various proportions with the amine co-initiator 2-dimethylaminoethyl methacrylate (DMAEMA) and used at two levels in which CQ + OPPI + DMAEMA = 1 wt.% or 3 wt.% to photoinitiate a BisGMA/BisEMA/TEGDMA (37.5:37.5:25 wt.%) monomer blend. A total of eight groups (four groups for each level of total photoinitiator, 1% and 3%) were tested according to the following proportion of components in the photoinitiator system: Group C: CQ only. Group CO: CQ + OPPI (1:2). Group CA: CQ + DMAEMA (1:2). Group COA: CQ + OPPI + DMAEMA (1:1:1). Each monomer was polymerized using a quartz-halogen curing unit (Demetron 400, Demetron Research Corp., Danbury, CT) with an intensity of 400 mW/cm 2 for 5 s, 20 s, 40 s, 60 s, 300 s and their conversion levels (DC) were determined at each exposure time using a Fourier transform infrared spectrophotometer (FTIR). To examine color stability, experimental composite resins were made by mixing 3.2% silanated barium glass (78 wt.%, average filler size; 1 μm) with each monomer system, except both CQ only group and 1% CO group, which were found to cure insufficiently to be able to prepare useful specimens. Disk-shaped samples (10 mm in diameter and 1.5 mm in thickness) were made and stored under the conditions of dry or saline solution at room temperature (25 °C) or 60 °C water bath. Each CIELAB scale was determined with a colorimeter (CHROMA METER CR-400) at the time of baseline (day after curing), 1 week, 2 weeks, and 4 weeks later. Results The high level (3%) photoinitiated groups exhibited greater DC than the low level (1%) groups. In the 3% group, the COA group showed the fastest and the highest DC, while in the 1% group the CA and COA groups showed the greatest DC. In the color stability test, both CA groups were darker and more yellow than the CO and COA groups. Color was more stable in composite resins containing OPPI than those containing only the CQ and amine components. The least color change (greatest color stability) was found using 25 °C saline solution aging, and the most change (least color stability) occurred using 60 °C dry air aging. Significance This study suggests that OPPI can be used to replace the amine in a given CQ/amine photoinitiator system to accelerate cure rate, increase conversion, reduce initial color and increase color stability.

Potassium Lactate and Fresh‐Pork‐Sausage Formulation Effects on Shelf Life in Lighted and Unlighted Display

ABSTRACT: The objective was to examine the effects of potassium lactate (KL) and raw‐meat blend on the shelf‐life of fresh‐pork‐sausage patties in lighted and unlighted display. Four fresh‐pork‐sausage blends (70% prerigor meat, 30% fresh‐pork trim; 80%/20%; 90%/10%; and 100%/0%) were formulated (n= 3) with 0% and 3% KL, and patties were displayed for 10 d at 4 °C in lighted display or for 7 d in unlighted display followed by 3 d in lighted display. Patties with KL had lower aerobic plate counts (APC), more stable color (greater a* and chroma, less visual discoloration), and less lipid oxidation (P &lt; 0.05) during display than did patties without KL. Patties in the light for 10 d were more discolored and had more lipid oxidation (P &lt; 0.05) than those in the dark for 7 d followed by the light for 3 d. Patties with KL in the light for 10 d had similar color (P &gt; 0.05) to patties without KL that were in the dark for the first 7 d. Adding KL resulted in similar color stability (P &gt; 0.05) among patties made from 80, 90, and 100% prerigor meat and greater color stability (P &lt; 0.05) than similarly formulated patties without KL. By using 3% KL, fresh‐pork‐sausage patty color stability was maximized, APC and lipid oxidation were minimized, and formulation costs can be decreased by using less‐expensive fresh‐pork trim for up to 20% of the blend. Adding KL also minimized the effects of display lighting on myoglobin and lipid oxidation.