scholarly journals Comparison of color indexes for tomato ripening

2004 ◽  
Vol 22 (3) ◽  
pp. 534-537 ◽  
Author(s):  
Andrés F. López Camelo ◽  
Perla A. Gómez
Keyword(s):  
Color Index ◽  
Human Perception ◽  
Color Difference ◽  
Color Classification ◽  
Color Changes ◽  
Color Categories ◽  
Visual Color ◽  
Postharvest Life ◽  
Range Of Values

Color in tomato is the most important external characteristic to assess ripeness and postharvest life, and is a major factor in the consumer's purchase decision. Degree of ripening is usually estimated by color charts. Colorimeters, on the other hand, express colors in numerical terms along the L*, a* and b* axes (from white to black, green to red and blue to yellow, respectively) within the CIELAB color sphere which are usually mathematically combined to calculate the color indexes. Color indexes and their relationship to the visual color classification of tomato fruits vine ripened were compared. L*, a* and b* data (175 observations from eleven cultivars) from visually classified fruits at harvest in six ripening stages according to the USDA were used to calculate hue, chroma, color index, color difference with pure red, a*/b* and (a*/b*)². ANOVA analysis were performed and means compared by Duncan's MRT. Color changes throughout tomato ripening were the result of significant changes in the values of L*, a* and b*. Under the conditions of this study, hue, color index, color difference and a*/b* expressed essentially the same, and the color categories were significantly different in terms of human perception, with hue showing higher range of values. Chroma was not a good parameter to express tomato ripeness, but could be used as a good indicator of consumer acceptance when tomatoes are fully ripened. The (a*/b*)² relationship had the same limitations as chroma. For vine ripened fruits, hue, color index, color difference and a*/b* could be used as objective ripening indexes. It would be interesting to find out what the best index would be if ripening took place under inadequate conditions of temperature and ilumination.

scholarly journals Changes in the Physical and Chemical Properties of Alder Wood in the Process of Thermal Treatment with Saturated Water Steam

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 898
Author(s):  
Michal Dudiak ◽  
Ladislav Dzurenda
Keyword(s):  
Thermal Treatment ◽  
Chemical Properties ◽  
Alnus Glutinosa ◽  
Color Difference ◽  
Average Density ◽  
Saturated Steam ◽  
Water Steam ◽  
Color Changes ◽  
Saturated Water ◽  
Range Of Values

The paper presents changes in color and selected physico-chemical properties of alder (Alnus glutinosa) wood during the process of thermal treatment of the wood with a saturated steam-air mixture or saturated water steam in the temperature range t = 95–125 °C for τ = 3 to 12 h. During the process of thermal treatment of alder wood, the original light white-gray color changes depending on the temperature and time of modification to soft reddish-brown to dark brown color shades. Color changes of alder wood expressed in the form of the total color difference are in the range of values ∆E* = 2.7–31.7. Measurements of the density of thermally treated alder wood in the dry state indicate that due to the thermal treatment of alder wood, the density decreases by ρ ≤ 4.6% compared to the average density of native alder wood. Due to the hydrolysis of hemicelluloses, in the process of thermal treatment of wet alder wood, its acidity changes in the range of values: pH = 4.9 to 3.1. Analyzes of ATR-FTIR spectroscopy indicate changes in alder wood extractants and hemicellulose degradation. A decrease in unconjugated and an increase in conjugated carbonyls was observed at all temperatures of thermal modification of alder wood. Measurements indicate changes in the lignin of alder wood and the fact that as the temperature increases, the formation of new carbonyls increases, which is reflected in the change of the chromophoric system.

Study on Color Classification of Pork with Computer Vision System Based on Different Color Difference Formula

2011 ◽  
Vol 474-476 ◽  
pp. 1638-1642 ◽  
Author(s):  
Hong Xia Zhao ◽  
Zhi Yang Luo ◽  
Xin Yuan ◽  
Yuan Li
Keyword(s):  
Computer Vision ◽  
Color Change ◽  
Vision System ◽  
Close Relation ◽  
Color Difference ◽  
Computer Vision System ◽  
Color Classification ◽  
Difference Formula ◽  
Different Color

The bad degree of meat and the color change have a close relation. Computer vision is not under the influence of physiological and psychological factor of person; Appraisement standard is objective and steady. Therefore, computer vision system has been established, which can do collection, management, display, and appraisement of porky color. The CIEL*a*b* and CIEDE2000 color difference formula were introduced into the classification of pork, the result was identical. Because the calculation course of CIEDE2000 color difference is complex, so the CIE1976L*a*b* color difference is still adopted to calculate color change at actual production.

Influence of Bleaching and Aging Procedures on Color and Whiteness of Dental Composites

2019 ◽  
Vol 44 (6) ◽  
pp. 648-658 ◽  
Author(s):  
A Della Bona ◽  
OE Pecho ◽  
R Ghinea ◽  
JC Cardona ◽  
RD Paravina ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Artificial Aging ◽  
Color Stability ◽  
Color Difference ◽  
Dental Composites ◽  
Whiteness Index ◽  
B Values ◽  
Color Changes ◽  
Visual Color ◽  
Difference Thresholds

SUMMARY Bleaching can cause perceptible color changes on resin-based composite (RBC) restorations that may not be stable with aging. The objective of this study was to evaluate color stability and whiteness variations of RBCs after bleaching and aging procedures. Discs (10 mm in diameter and 1 mm thick) of shades A2 and A3 were fabricated from two RBCs (Filtek Z250 and Filtek Z350 XT) and divided into three subgroups (for each composite and shade) (n=5) as follows: control (no bleaching), at-home bleaching, and in-office bleaching. All specimens underwent an accelerated artificial aging up to 450 KJ/m2 and 900 KJ/m2 in an aging chamber (Suntest XXL+). A spectroradiometer (SpectraScan PR-670) was used to obtain CIE L*a*b* coordinates. CIEDE2000 color difference (ΔE00) and whiteness index for dentistry (WID) were used to evaluate color stability. Color and whiteness differences data were analyzed considering the 50:50% visual color difference thresholds (perceptibility [PT] and acceptability [AT]) and 50:50% whiteness thresholds (whiteness perceptibility [WPT] and whiteness acceptability [WAT]). Analysis of variance and Tukey tests (α=0.05) were used to statistically analyze the data. After bleaching, all specimens showed ΔE00 and ΔWID values below their corresponding acceptability thresholds (AT and WAT, respectively). After aging, L* and WID values decreased while b* values increased (p≤0.05), resulting in ΔE00 and ΔWID values above AT and WAT, respectively. Color changes after bleaching RBCs were clinically acceptable, while aging provoked clinically perceptible color changes.

scholarly journals Kernel Color of Three Black Walnut Cultivars after Delayed Hulling at Five Successive Harvest Dates

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2256-2258 ◽  
Author(s):  
Michele Renee Warmund
Keyword(s):  
Narrow Range ◽  
Color Classification ◽  
Color Changes ◽  
The Third ◽  
Kernel Color ◽  
Harvest Dates ◽  
Visual Color ◽  
Hue Angle ◽  
Mean Kernel ◽  
Time Of Harvest

‘Emma K’, ‘Kwik Krop’, and ‘Sparrow’ black walnuts (Juglans nigra L.) were collected weekly in Sept. and Oct. 2007 to determine the effect of delayed hulling of fruits on kernel color at successive harvest dates. Delayed hulling of fruits resulted in lower kernel color values, including L*, chroma, hue angle, and LCH sum (L* + chroma + hue angle values) than those of fruits that were immediately hulled after harvest. ‘Sparrow’ kernels were visually the darkest brown color after delayed hulling. However, the effect of delayed hulling (i.e., change in kernel LCH sum values) over all harvest dates was greatest for ‘Emma K’. LCH sums of kernels generally decreased as the time of harvest was delayed. For ‘Sparrow’, mean kernel LCH sums from immediately hulled fruits decreased sharply from the third week of harvest on 20 Sept. (i.e., the “normal” date of harvest) to the next week. This decrease in LCH sums represented a change in kernel color classification from medium brown at Week 3 to dark brown in Week 4. Visual color changes for ‘Kwik Krop’ were less apparent as a result of the narrow range of color over harvest dates.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Packaging Solutions to Extend the Shelf Life of Green Asparagus (Asparagus officinalis L.) ‘Vegalim’

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 478
Author(s):  
Stefania Toscano ◽  
Valeria Rizzo ◽  
Fabio Licciardello ◽  
Daniela Romano ◽  
Giuseppe Muratore
Keyword(s):  
Shelf Life ◽  
Color Difference ◽  
Asparagus Officinalis ◽  
Total Phenolic ◽  
Postharvest Life ◽  
Sensory Color ◽  
Highly Correlated ◽  
Enzymatic Changes ◽  
Green Asparagus

The aim of the study was to assess, through a comparative shelf-life test, the suitability of two packaging materials, namely macro-perforated polypropylene (PP MA) and micro-perforated coextruded polypropylene (PP C), for the quality preservation of green asparagus (Asparagus officinalis L. ‘Vegalim’). Quality of spears was evaluated during 30 days at refrigerated storage by monitoring chemical, physical, and enzymatic parameters as well as sensory descriptors. PP C kept headspace composition close to suggested values for fresh green asparagus. Total color difference increased during the storage and it was highly correlated with chlorophyll-a and carotenoids, however, sensory color perception did not change significantly until 22 days of storage. PP C maintained ascorbic acid concentrations close to the initial levels, limited total phenolic compound loss to 24% (45% in PP MA), determined an increase of 72% in fiber content and small changes in lignin value; enzymatic changes were significantly inhibited. Significant sensorial differences were detected after 22 days of storage, with PP C performing better than PP MA. PP C film was confirmed as the best choice, limiting weight loss and maintaining a fresh-like appearance during 30 days of storage, thus allowing an extension in postharvest life.

An Application and Research of Gray-Relation for Color Classification in Dyeing Textile

2013 ◽  
Vol 694-697 ◽  
pp. 2881-2885
Author(s):  
Hai Yan Wang ◽  
Jian Xin Zhang
Keyword(s):  
System Analysis ◽  
High Efficiency ◽  
Information Management System ◽  
Space Distribution ◽  
Color Classification ◽  
Uniform Sampling ◽  
Forecast Precision ◽  
Internal Instability ◽  
The Stability

Dyeing textile’s information management system is the basis of accurate classification of color， machine studying methods have became a popular area of research for application in color classification. Traditional classification methods have high efficiency and are very simple ， but they are dependent on the distribution of sample spaces. If the sample data properties are not independent， forecast precision will been affected badly and internal instability will appear. An application of Gray-Relation for dyeing textile color classification has been designed， which offsets the discount in mathematical statistics method for system analysis. It is applicable regardless of variant in sample size， while quantizing structure is in agreement with qualitative analysis. On the basis of theoretical analysis， Dyeing textile color classification was conducted in the conditions of random sampling、 uniform sampling and stratified sampling. The experimental results proofs that by using Gray-Relation， dyeing textile color classification does not need to be dependent on sample space distribution， and increases the stability of classification.

scholarly journals PENGARUH RESIN TERHADAP PERUBAHAN WARNA PADA CAT TEMBOK

2019 ◽  
Vol 5 (2) ◽  
pp. 132
Author(s):  
Nurlela Nurlela ◽  
Risnawati Risnawati
Keyword(s):  
Film Thickness ◽  
Vinyl Acetate ◽  
Polyvinyl Acetate ◽  
Color Change ◽  
Color Difference ◽  
Background Color ◽  
Color Changes ◽  
Synthetic Resins ◽  
Color Background

The Influence of Resin against the Change of Color on the Wall PaintThe quality of the paint is determined by the resin used. Synthetic resins for polymer paints are made by combining several monomers to achieve various characteristics. The incorporation of some monomers such as polyvinyl acetate resin, acrylic vinyl resin and acrylic styrene resin which act as a binder can affect the quality of the paint especially the color change. The purpose of this study is to find the color changes that occur on the wall paint by using Poly Styrene Acrylic , Poly Vinyl Acetate and Poly Vinyl Acrylic. From the results of the measurement of color difference, significant color change occurs in the Poly Vinyl Acetate (PVAc) + Poly Vinyl Acrylic (PVA) and Poly Styrene Acrylic (PSA). The results of the quality test of the three resins based on pH test, scrub test and viscosity test, PSA has better quality compared to PVA + PVAc and PVA resin. From the color difference measurement test, some things need to be considered, are temperature, film thickness, substrate color/background color and measurement conditions (measured in wet sample/in plate/dry surface) and test on resin added additive according to the type of each resin.Keywords: Paint, Resin, Color Changes, Poly Vinyl Acetate, Poly Styrene.ABSTRAK Kualitas dari cat sangat ditentukan oleh resin yang digunakan. Resin sintetis untuk cat berupa polimer yang dibuat dengan menggabung beberapa monomer untuk mencapai berbagai karakteristik. Penggabungan dari beberapa monomer seperti resin poli vinil asetat, resin vinil akrilik dan resin stirena akrilik yang berfungsi sebagai pengikat mampu mempengaruhi kualitas cat terutama dari perubahan warna. Tujuan dari penelitian ini adalah untuk mengetahui perubahan warna yang terjadi pada cat tembok dengan menggunakan Poli Stirena Akrilik, Poli Vinil asetat dan Poli Vinil Akrilik. Dari hasil pengukuran perbedaan warna, perubahan warna cukup signifikan terjadi pada resin Poli vinil Asetat (PVAc) + Poli Vinil Akrilik (PVA) dan resin  Poli Stirena Akrilik (PSA). Hasil uji Kualitas cat dari ketiga resin berdasarkan uji pH, uji scrub dan uji viscositas, PSA memiliki kualitas yang lebih baik dibandingkan dengan resin PVA+PVAc dan PVA. Dari pengujian pengukuran perbedaan warna, beberapa hal yang perlu di perhatikan, yaitu suhu, film thickness, warna substrat/background color dan kondisi pengukuran (diukur dalam keadaan wet sample/dalam bentuk plate/dry surface) dan pengujian terhadap resin yang ditambahkan zat aditif yang sesuai dengan tipe masing-masing resin tersebut.Kata Kunci: Cat, Resin, Perubahan Warna, Poli Vinil, Poli Stirena.

scholarly journals Democratizing the access to college education: Brazilian race/color classification in affirmative action’s debate

2018 ◽  
Vol 26 (100) ◽  
pp. 595-618
Author(s):  
Moema De Poli Teixeira
Keyword(s):  
Public Policy ◽  
Affirmative Action ◽  
Race Relations ◽  
College Education ◽  
Target Population ◽  
Two Dimensions ◽  
The Other ◽  
Color Classification ◽  
Racial Identities ◽  
Color Categories

Abstract One of the principal aspects to develop affirmative action in Brazil comprises how to define target population, which includes uses and perceptions of ethnic/racial/color categories. The present paper has the main objective of bringing the analysis about IBGE’s2 race/color classifications contribute to the design of affirmative action in Brazil using categories historically constructed with the endorsement of official statistics. The color issues in the Brazilian Census and the experiences, including the racial designation as an open response, has been studied since 1872, and it is noted that there are two dimensions to be observed in the affirmative action debate: a structural and other cultural involving race/color classifications in Brazil. The statistics are fundamental to build the best evidence in shaping public policy. On the other hand, we must recognize ethnic and racial identities as cultural phenomena that are susceptible to change, which drives us to continue the discussion, trying to capture the meaning of these transformations. The affirmative action debate may not disqualify any of these approaches to knowledge about race relations in Brazil.

scholarly journals Preparation and Characterization of Natural Bleaching Gels Used in Cosmetic Dentistry

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2106 ◽  
Author(s):  
Amalia Mazilu (Moldovan) ◽  
Codruta Sarosi ◽  
Marioara Moldovan ◽  
Filip Miuta ◽  
Doina Prodan ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Dental Materials ◽  
Color Difference ◽  
Cytotoxicity Test ◽  
Color Changes ◽  
Vis Spectroscopy ◽  
Color Shift ◽  
Follicle Stem Cells ◽  
Bleaching Gels

The novelty of this study consists of the formulation and characterization of three experimental bleaching gels with hydroxylapatite oxides and fluorine (G28®, G29®, G30®) based on natural fruit extracts compared to the commercial Opalescence 15% (GC, Ultradent, South Jordan, UT, USA). Studies have been conducted on the effect that the experimental bleaching gels have on the color and morphology of different restorative materials (Nanofill®-Schulzer, P.L. Superior Dental Materials GmbH, Hamburg, Germany, and experimental nanocomposites (P11®, P31®, P61®)), immersed in coffee and artificial saliva (for 10 days and 30 days). The study also includes a cytotoxicity test on the gels and nanocomposites after bleaching, with ISO 109993-5 protocols on human dental follicle stem cells. UV-VIS spectroscopy, computerized measurement, and fluorescence spectrometry were used in order to observe the color changes, while the microstructure of the surface was investigated by Scanning Electron Microscopy (SEM). All of the samples immersed in coffee showed the highest color shift in comparison to the baseline. The color difference ΔE values obtained using the two methods (UV-Vis, computerized based on digital images) both after coloring and bleaching, respectively, were different for all four types of nanocomposites stored in the coffee, while no difference was observed in those stored in artificial saliva. The studied experimental gels and nanocomposites had a low cytotoxic effect on cell cultures after bleaching.

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