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Color Measurement (color + measurement)
Selected AbstractsUse of Shade Guides for Color Measurement in Tooth-Bleaching StudiesJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 2003WILLIAM D. BROWNING DDS ABSTRACT Several different methods are used to measure tooth color in bleaching studies. The ADA Acceptance Program Guidelines for Home Use Tooth Whitening Products specify the use of a value-oriented shade guide and/or electronic color measurement devices. Since people perceive color differently, shade guides are a subjective measure. Differences between raters and by the same rater are well documented in the dental literature. The purposes of this article will be to discuss the advantages and disadvantages using shade guides to measure color change related to tooth whitening, and to evaluate the correlation of data gathered from the use of shade guides to electronic color measurement devices. Using an order published by the manufacturer, both the TRUBYTE® Bioform and Vita Classical guides can be arranged by value. A study by O'Brien demonstrated however, that the order is flawed and the change in brightness from tab to tab varies greatly. Despite these disadvantages, a review of data from several clinical trials demonstrates that Vita Classical shade guide data is consistent with data gathered using electronic color measurements. Furthermore, the O'Brien data can be used to make both these guides better measurement systems. The ADA Certification program standards define the degree of overall color change that should be considered clinically important. This issue is as critical as the measurement system used. Reporting color changes that are neither detectable to the human eye nor considered by the public to be important offers the profession little usable information. Given that any standard for color change during bleaching must relate to the abilities of the human eye, it is the conclusion of the author that shade guides should remain a critical element of any bleaching study. CLINICAL SIGNIFICANCE Clinicians are frequently exposed to reports of bleaching agents that have been shown to result in a change of 6, 7, 8, etc., tabs. Without understanding the limitations of the shade guide used, reports of a specific shade tab change are of little use and may actually be misleading. [source] DIFFERENTIATION OF CURED COOKED HAMS BY PHYSICO-CHEMICAL PROPERTIES AND CHEMOMETRICSJOURNAL OF FOOD QUALITY, Issue 1 2009VITTORIO M. MORETTI ABSTRACT Comparison of physico-chemical and compositional traits was carried out on cooked hams. Deboned fresh pig thighs of three different origins were divided into three batches: 200 pig thighs from the Italian market, H1; 200 from The Netherlands, H2; and 200 from Denmark, H3. Boneless pig thighs were processed under commercial guidelines for production of cooked hams, using brine at 25% level of injection. After processing, 12 cooked hams from each batch were sampled randomly and analyzed for proximate and fatty acid composition. Color measurement was performed on the muscles: biceps femoris, semimembranosus, and semitendinosus. H1 hams showed a higher weight loss and a lower technological yield compared to H2 and H3 hams. Analysis of variance on compositional data showed that H1 hams had a lower moisture/protein ratio, a higher fat content, a lower percentage of, -linolenic, eicosapentaenoic and docosahexaenoic acid, and a higher percentage of myristic and palmitic acids when compared to H2 and H3 hams (P < 0.05). Analysis of color of the three muscles demonstrated that hams from the H1 group had the highest a* values. The application of linear discriminant analysis demonstrated that the use of only four variables allowed to correctly discriminate among groups of cooked hams. PRACTICAL APPLICATIONS The following are the practical applications of this research. The comparison of physico-chemical and compositional traits were carried out on cooked hams. Pig thighs of different origin were processed under commercial guidelines. The physicochemical parameters of cooked hams were defined and showed some differences characterizing the products. [source] Determination of the Minimal Erythema Dose and Colorimetric Measurements as Indicators of Skin Sensitivity to UV-B Radiation,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2004Sérgio Dornelles ABSTRACT There is a strong relation between chronic UV-B-induced sunburns and the development of skin cancer. Therefore, it is important to obtain a method that can be reproduced easily to detect individuals with similar skin color but different sensitiveness to sun exposure. The study evaluated 193 healthy volunteers (68% women; the average age was 38 years). They were divided into six groups of at least 30 subjects, according to skin type. The minimal erythema dose (MED) was assessed in two non-sun-exposed areas (thorax-infra-axillary area and on the buttocks), using a UV-B source (0.5 mW/cm2), with openings of 1 cm2, in increasing doses. The same areas were evaluated with a Minolta CR 300 Chromameter (L*a*b* system). The MED values ranged from 13 to 156 mJ/cm2; the coordinate L* (brightness) ranged from 75.96 to 30.15. The correlation between the MED and the brightness was negative in both areas (Pearson's correlation r =,0.91, P < 0.05). Color measurements, especially brightness, can be used to quickly assess skin sensibility. Considering the MED, there is a substantial overlapping of adjacent phototypes, but they could be separated into two groups: more sensitive individuals (Types I, II, III and IV) and less sensitive ones (Types V and VI). [source] Skin color measurement in Chinese female population: analysis of 407 cases from 4 major cities of ChinaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 8 2007Liu Wei MD Background, Color assessment of human skin is an important index both in dermatology and in cosmetology. Methods, Skin color measured in 407 Chinese women selected from four different cities in China is reported in the 1976 Commission International de L'eclairage (CIE)-color space, according to the skin color typing method proposed by Chardon et al. in 1991. The skin color of buttocks and hands, which represent sun unexposed and exposed sites, respectively, were measured with a Minolta 2500d chromameter. Individual typology angle (ITA°) of each volunteer was calculated based on the measured L* and b* values and her skin complexion was graded accordingly. Results, The results show that most of the volunteers had a "light" skin color at their unexposed sites, namely grade II (65.5%), and then grade III (intermediate, 23.1%), and I (very light, 9.6%). The skin colors at exposed sites of the studied group were mainly grade III (intermediate, 45.7%), followed by grade IV (tan, 42.0%) and II (light, 7.9%). The difference among the investigated cities, the relationship between skin color and ages, and the complexion changes from unexposed site to exposed site were analyzed based on the data from the research. Conclusion, The authors believed that the present results might basically represent the complexion conditions of Chinese women. [source] EFFECT OF YAM VARIETY ON THE PASTING PROPERTIES AND SENSORY ATTRIBUTES OF TRADITIONAL DRY-YAM AND ITS PRODUCTSJOURNAL OF FOOD QUALITY, Issue 3 2008J.M. BABAJIDE ABSTRACT Six varieties of yam were processed into traditional dry-yam slices. The pasting properties and sensory attributes of dry-yam samples, flour and paste from the flour were investigated. Significant differences (P , 0.05) were observed in the pasting properties of flour from different yam varieties. "Ijedo," the commonly used variety, had the highest peak, trough and final viscosities. There was no significant difference in the viscosities of "Efuru" (206.04 rapid viscosity analyzer), "Ise-Osi" (242.75 rapid viscosity unit [RVU]) and "Abuja" (241.25 RVU) varieties. Samples of dry yam made from "Efuru,""Ise-Osi" and "Abuja" yams were not significantly different (P > 0.05) from "Ijedo" in terms of instrumental color measurement, as their degree of brownness (100 , L*) were 21.53, 19.21, 20.87 and 22.42, respectively. There was no significant difference (P > 0.05) in color, taste and moldability of the paste made from "Efuru,""Ise-Osi,""Ijedo" and "Abuja" yams. There was no significant difference (P > 0.05) between the hardness of dry yams made from "Ise-Osi,""Ijedo" and "Abuja." There were positive correlations between the yam paste moldability, peak, trough and final viscosities for the different yam varieties. "Ise-Osi,""Efuru" and "Abuja" varieties were found to be suitable for dry-yam processing in terms of sensory property and pasting of dry-yam slices and their products, which were not significantly different from those of "Ijedo" variety , the commonly used yam. PRACTICAL APPLICATIONS The study revealed that dry-yam processors and potential dry-yam processors in Nigeria can use other white yam varieties, such as "Abuja,""Ise-Osi" and "Efuru," apart from "Ijedo" variety , the commonly used yam variety. These yam varieties were also acceptable in terms of the sensory and pasting properties of dry-yam slices and their products. Thus, the general knowledge that white yams are good for dry-yam processing has been scientifically verified. [source] SENSORY PROFILING AND POSITIONING OF JILEBI SAMPLES BY MULTIVARIATE ANALYSISJOURNAL OF FOOD QUALITY, Issue 6 2004MAYA PRAKASH ABSTRACT Sensory profilograms based on the quantitative descriptive analysis (QDA) of jilebi using 12 attributes were drawn for nine market samples. The instrumental texture measurement of shear values and CIE color measurement for L*, a* and b* were determined for all the samples. Further, canonical discriminant analysis was run to position the samples. The results indicated that samples 9, 4 and 5 were grouped together in the same quadrant, which represented desirable attributes of jilebi viz, crispness, sweetness, glossy appearance and overall quality (OQ). Samples 6, 8 and 2 have taken a different quadrant with attributes like juicy and porous; while sample 3 was away in a separate quadrant with undesirable attribute namely heated oil. Crispness of jilebi had high positive correlation with OQ and texture (shear value). [source] Preference Mapping of Commercial Toasted White Corn Tortilla ChipsJOURNAL OF FOOD SCIENCE, Issue 5 2002J.-F. Meullenet ABSTRACT: This study was conducted to identify what constitutes consumer preference for and acceptance of white corn tortilla chips. Consumer overall acceptance of tortill chips was modeled by consumer data for acceptance of appearance, flavor, and texture and by descriptive sensory and/or instrumental data. Internal preference mapping (R2= 0.99) showed that flavor was the most important attribute to consumer overall acceptance followed by texture and appearance. The basic salt attribute and aftertaste attributes of salt, raw masa, and toasted grain aftertastes were important to consumer flavor acceptance, and the attributes of crispness, loose particles, hardness and oily/greasy film were responsible for consumer acceptance of texture. One appearance descriptive attribute (char marks) and 1 instrumental color measurement (a) were significantly related to consumer acceptance of appearance. [source] Effects of boning method and postmortem aging on meat quality characteristics of pork loinANIMAL SCIENCE JOURNAL, Issue 5 2009Chunbao LI ABSTRACT This work investigated the effects of boning method and postmortem aging on pork loin color, shearing value and sensory attributes. Two experiments were assigned. In Experiment I, 30 Chinese native black pigs were slaughtered and their carcasses were divided into three groups: (i) hot-boning: carcasses were fabricated within 45 min postmortem just after dressing; (ii) cold boning at 24 h: carcasses were fabricated after chilling at 0°C for 24 h; (iii) cold boning at 36 h: carcasses were fabricated after chilling at 0°C for 36 h. In Experiment II, right sides of the second group in Experiment I were used and primal cuts were vacuum packed and aged for 1 day, 8 days and 16 days. Pork loins (Longissimus lumborum) were used for color measurement, shearing test, and sensory evaluation. Among three boning methods, cold-boning at 36 h postmortem had the advantages of giving muscles a better color, the lowest cooking loss and cooked shearing value, and the highest sensory tenderness, juiciness, flavor and overall liking. Postmortem aging could improve pork quality characteristics, but it is not the fact that the longer aging time is, the better pork quality would be. Eight days may be enough to obtain an acceptable sensory attribute. These results are meaningful for pork processing and pork consumption. [source] Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid foodBIOTECHNOLOGY PROGRESS, Issue 3 2010Nils Tippkötter Abstract Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L,1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. © 2010 American Institute of Chemical Engineers Biotechnol. Prog. 2010 [source] Use of Shade Guides for Color Measurement in Tooth-Bleaching StudiesJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 2003WILLIAM D. BROWNING DDS ABSTRACT Several different methods are used to measure tooth color in bleaching studies. The ADA Acceptance Program Guidelines for Home Use Tooth Whitening Products specify the use of a value-oriented shade guide and/or electronic color measurement devices. Since people perceive color differently, shade guides are a subjective measure. Differences between raters and by the same rater are well documented in the dental literature. The purposes of this article will be to discuss the advantages and disadvantages using shade guides to measure color change related to tooth whitening, and to evaluate the correlation of data gathered from the use of shade guides to electronic color measurement devices. Using an order published by the manufacturer, both the TRUBYTE® Bioform and Vita Classical guides can be arranged by value. A study by O'Brien demonstrated however, that the order is flawed and the change in brightness from tab to tab varies greatly. Despite these disadvantages, a review of data from several clinical trials demonstrates that Vita Classical shade guide data is consistent with data gathered using electronic color measurements. Furthermore, the O'Brien data can be used to make both these guides better measurement systems. The ADA Certification program standards define the degree of overall color change that should be considered clinically important. This issue is as critical as the measurement system used. Reporting color changes that are neither detectable to the human eye nor considered by the public to be important offers the profession little usable information. Given that any standard for color change during bleaching must relate to the abilities of the human eye, it is the conclusion of the author that shade guides should remain a critical element of any bleaching study. CLINICAL SIGNIFICANCE Clinicians are frequently exposed to reports of bleaching agents that have been shown to result in a change of 6, 7, 8, etc., tabs. Without understanding the limitations of the shade guide used, reports of a specific shade tab change are of little use and may actually be misleading. [source] 175 Toward an Optical Biogeography of the OceansJOURNAL OF PHYCOLOGY, Issue 2003A. M. Wood Remote sensing of ocean color has revolutionized our ability to understand the processes leading to the observed distribution of different taxa in marine waters. Many scientists in the remote sensing and optics community are working toward retrieval of species distributions using ocean color measurements to derive the concentration of recognized chemotaxonomic markers. In this talk, I work toward an optical biogeography of the ocean by viewing the optical environment as a selection regime that creates biogeographic boundaries or "optical fences" defining the distribution of taxa with different light harvesting systems and/or different physiologies. Working primarily with data from a wide range of tropical, sub-tropical, and warm temperate coastal margins, I show that there is a close association between the distribution of different spectral forms of PE-containing picocyanobacteria and the optical properties of the water masses in which they are found. This pattern also appears to be reflected in the distribution some dinoflagellate taxa, indicating that the optical environment encompasses a range of key niche parameters that, in turn, determine the biogeographic distribution of species. [source] PREFERENCE MAPPING OF COLOR OF URUGUAYAN HONEYSJOURNAL OF SENSORY STUDIES, Issue 5 2007ADRIANA GÁMBARO ABSTRACT The color of 30 honey samples, both from unifloral and multifloral origin, was characterized using Pfund scale and CIE L*a*b* tristimulus method. A panel of 140 consumers evaluated the color acceptability of the samples using a 9-point structured scale. The color of the samples was differentiated (P < 0.001) by both instrumental methods, which confirms the validity of using them to characterize the color of honey. Consumers showed highly significant different degrees of liking for the color of the evaluated honeys. Two clusters (cluster 2 and cluster 3) with different preference patterns were identified; one liked intermediate-colored honeys, and the other preferred dark reddish honeys. External preference mapping was used to model color acceptability for consumers in each cluster using the first two principal components of the principal component analysis of the instrumental color data. PRACTICAL APPLICATIONS The key finding of this study is the comparison of Pfund scale and CIE L*a*b* method to characterize the color of honey, and the relationship of instrumental color measurements and consumer preferences. Although the Pfund scale showed the highest discrimination between samples, it does not take into account the tone of the color of the samples and was not enough to the color of honeys. Preference mapping provided insight into the aspects that are important for consumers when deciding the acceptability of color in honey. Results showed that Uruguayan consumers seemed to dislike light-colored honeys. [source] Genetic admixture, self-reported ethnicity, self-estimated admixture, and skin pigmentation among Hispanics and Native AmericansAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Yann C. Klimentidis Abstract The relationship between ethnicity and biology is of interest to anthropologists, biomedical scientists, and historians in understanding how human groups are constructed. Ethnic self-identification in recently admixed groups such as Hispanics, African Americans, and Native Americans (NA) is likely to be complex due to the heterogeneity in individual admixture proportions and social environments within these groups. This study examines the relationships between self-identified ethnicity, self-estimated admixture proportions, skin pigmentation, and genetic marker estimated admixture proportions. These measures were assessed using questionnaires, skin color measurements, and genotyping of a panel of 76 ancestry informative markers, among 170 Hispanics and NAs from New Mexico, a state known for its complex history of interactions between people of NA and European (EU) ancestry. Results reveal that NAs underestimate their degree of EU admixture, and that Hispanics underestimate their degree of NA admixture. Within Hispanics, genetic-marker estimated admixture is better predicted by forehead skin pigmentation than by self-estimated admixture. We also find that Hispanic individuals self-identified as "half-White, half Hispanic" and "Spanish" have lower levels of NA admixture than those self-identified as "Mexican" and "Mexican American." Such results highlight the interplay between culture and biology in how individuals identify and view themselves, and have implications for how ethnicity and disease risk are assessed in a medical setting. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Effect of laser cleaning on granite colorCOLOR RESEARCH & APPLICATION, Issue 2 2007Carlota M. Grossi Abstract This article presents the effect of laser radiation on the color of ornamental granites used for external cladding. The laboratory experimentation was undertaken on a widely used coarse-grain granite commercially known as Rosa Porriño. The irradiation was carried out with a Q-switched Nd:YAG laser at 1064 nm and several energy densities (fluences) on polished surfaces, dry and wet, uncoated, and artificially coated-simulating a black crust. Laser effects on the granite surface were determined by color measurements with a colorimeter. These measurements made possible to determine probable damage due to laser radiation and the diverse response of different minerals. The analysis of the data also suggests potential causes for the color change and applicability limits of the technique. The a*-parameter, or red,green component, is the most affected, leading to a change in hab (hue) and was interpreted as a result in variations in the Fe compounds, which strongly condition stone color. No significant changes in L* (luminosity or lightness) or Cab* (chroma) may indicate no relevant alterations in the surface polish. When using laser irradiation to remove black layers on granite surfaces, variations of L* can be indicative of the cleaning effectiveness. This research results may be useful to select laser parameters when managing ornamental granite cleaning operations. However, they also suggest the need of further experimentation in specific techniques of analysis as well as different laser wavelengths. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 152 , 159, 2007 [source] | ||||||||||||||||