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A cor nos ambientes industriais: normas e legislação; The colour in industrial environment: rules and law

Peixoto, Elaine Alcantara Freitas
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/04/2013 Português
Relevância na Pesquisa
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O objetivo deste trabalho foi analisar o uso da cor em ambientes internos industriais, sendo regidos por legislação e normatização específicas, uma vez que envolvem atividade de trabalho humano. Numa primeira etapa é apresentada pesquisa bibliográfica com intuito de caracterizar as exigências legais que definem o uso da cor para estes ambientes. Identifica-se a legislação relacionada à Segurança do Trabalho, de abrangência nacional -- em conformidade com o Ministério do Trabalho e Emprego; e outras de abrangência mais restrita. Por exemplo, o contexto estadual de São Paulo, que disciplina orientações do Corpo de Bombeiros e Centro de Vigilância Sanitária da Secretaria de Estado da Saúde. Sob a ótica da Segurança do Trabalho, são avaliadas a aplicação de cores em: máquinas, equipamentos, elementos construtivos, indicação de localização de equipamentos e sinalização de segurança. O uso de vários matizes para situações distintas propicia ao trabalhador o reconhecimento de vários cenários por meio de padronização de informação; possibilitando-lhe tomar ciência da presença de um material e os riscos e perigos a ele relacionados. Paralelamente, o presente estudo compreendeu pesquisa de campo para efeito de registros fotográficos de ambientes de trabalho: isto foi feito para exemplificar os tópicos estudados. Ao considerar a presença do trabalhador...

Influence of natural weathering on colour stability of materials used for facial prosthesis

Dos Santos, D. M.; Goiato, M. C.; Sinhoreti, M. A C; Moreno, A.; Dekon, S. F C; Haddad, M. F.; Pesqueira, A. A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 267-270
Português
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Colour stability of resin and silicone is an important factor for longevity of facial prostheses. The aim of this study was to evaluate the colour stability of resins and silicone for facial prostheses. Three brands of acrylic resin and one of facial silicone were evaluated considering pigment incorporation for the colourless materials. Ten samples of each material were fabricated and submitted to measurements of chromatic alteration initially and after 90 and 180 days of weathering natural through visual analysis and spectrophotometry. Data were evaluated by ANOVA and Tukey test (p < 0.05). Statistically significant colour alteration was observed among some materials regardless of the period. The materials did not present a statistical difference between 90 and 180 days except for the pigmented heat-polymerized resin. The colour difference between pigmented Silastic MDX4-4210 and colourless Silastic was statistically significant (p < 0.01) in both periods as well as between pigmented and colourless heat-polymerized resin, and between the resins Rapidaflex and Lentaflex. The visual method demonstrated colour alteration in all materials evaluated during the first 90 days of ageing. All materials exhibited colour alteration due to exposure to environment. © 2012 Informa UK...

Role and functions of colour in the drawings of Portuguese architects

Moutinho, Natacha Antão; Durão, Maria João
Fonte: International Colour Association (AIC) Publicador: International Colour Association (AIC)
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 Português
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Drawings made by architects have been the object of several studies and publications, however, usually focused on themes that encompass skills, methods, conventions, or representations. This paper addresses drawings done by Portuguese architects, from a completely different standpoint: an enquiry directed to the role of colour. It is generally accepted that colour is a very significant tool and a powerful means of expression, operating at many perceptive levels that can add information and meaning to an image. However, specifically when related to drawings made during the development of an architectural project, how significant is colour in the actual ‘making of the drawing’ and what meanings are attached to it when part of a range of steps and different stages of this complex process? These were the leading research questions that initiated an ongoing investigation within a PhD program in Fine Arts – specialization in Drawing that responds to more overarching issues such as how colour triggers the imagination and thinking process. From the analysis of drawings and discussion with their authors, significant functions and uses of colour began to emerge. Some applications of colour are more straightforward and illustrative in essence than other more personal interpretations and explorations of colour. In fact...

Flowers dressing down: reduced flower colour associated with a shift from outcrossing to self-fertilization in a coastal dune plant.

Button, Lindsey Grace
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
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Shifts in flowering plants from outcrossing to self fertilization are the most significant and common shifts in reproductive mode. Some differences in floral morphology between outcrossing and selfing plants have been examined, but no research has examined the change in colour across a shift within a single species. Camissoniopsis. cheiranthifolia exhibits a full range of mating systems, from obligate outcrossers to obligate selfers, and everything in between, and thus provides an ideal opportunity to examine this trend. Colour components such as brightness, chroma and hue were calculated from percent reflectance of flower petals from populations in the field. Brightness and chroma were higher for outcrossing populations than for selfing populations, and exhibited a positive correlation with the level of outcrossing estimated using genetic analysis of progeny arrays, indicating an advantage of increased colour for outcrossing populations. Hue was shifted from yellow towards red in selfing populations. Because flowers change colour in the same way as they age and selfing flowers are shorter-lived than outcrossing flowers, this shift could be indicative of hastened senescence. Populations grown from seed in a common glasshouse experiment exhibited the same trends...

The Origin of Colour in Diamond

Scott, Graeme C.
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
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Colour in diamond has long been both a mystery and a novelty. Dating back to antiquity, coloured diamonds have been admired and desired for their rarity and aesthetic beauty. The causes of colour, however, are not always completely understood. Natural diamond is determined to be gem-worthy based on the four C’s of quality: cut, clarity, carat, and colour. The most common colour occurrence in diamonds is in fact no colour at all, also termed a white diamond. The extremely high refractive index in a pure white diamond splits the visible spectrum out of white light and reflects back with all the colours of the spectrum, giving the diamond its characteristic fire. Very few coloured diamonds owe their colouration to the presence of mineral or elemental inclusions with some very notable exceptions of blue, yellow and black, which owe their colouration primarily to the presence of boron, nitrogen and graphite components respectively. Brown, red, pink and purple are believed to owe their colour to plastic deformation within the crystal lattice. Colouration of green, opaque white and in particular chameleon diamonds remains enigmatic with several theories existing but no conclusive answer can yet be determined. Throughout history their have been attempts to alter a diamonds colour...

Influence of Sympatry and Sexual Selection on Colour Pattern Divergence in Birds-of-Paradise (Paradisaeidae)

Giglio, Victoria
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
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The extraordinary colour patterns displayed by the birds-of-paradise have interested biologists for many generations and yet our understanding of the evolution these colour patterns remains limited. In this study, we first test for and find that degree of sympatry is associated with degree of colour pattern divergence among males and females. Secondly, we test for relations between degree of sexual selection and colour pattern divergence, and find that degree of sexual selection is only associated with degree of ranked colour pattern evolution among older lineages of females. Thirdly, we compare rates of colour pattern evolution among birds-of-paradise, high latitude birds and low latitude birds, and find that the rate of colour pattern evolution among birds-of-paradise is not significantly different from the rate of colour pattern evolution among high latitude birds or low latitude birds. We suggest that sympatry is important to the evolution of colour patterns among birds-of-paradise. We argue that colour patterns diverged in sympatry via reinforcement as a result of females’ preference for the elaborate male, high rates of hybridization and the general low fitness of hybrids.; N/A

Environmental colour influences the behaviour of black-capped chickadees (Poecile atricapillus)

Rocheleau, Lydia Belle
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
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Colour perception plays a critical role in many aspects of an animal’s life, such as in mate selection, foraging, predator avoidance, habitat navigation, and communication. I aimed to look at how an animal’s behaviour is changed as it is exposed to differently coloured environments. Colour has effects on behaviour and emotion in humans, but this subject that has not been well studied in other animals. For example, in humans, certain colours are associated with particular feelings, and might arouse particular emotions and physiological responses (called colour psychology), although such mood associations with colours can vary across cultures. I attempted to address this subject by looking at how colour affects the behaviour of the black-capped chickadee, a small, monochromatic North American songbird. Experimenting with a monochromatic bird confers the benefit of eliminating any colour bias associated with mate selection and within-species communication between adults. I presented individual chickadees with two cages differing only in their interior colour. I video recorded chickadees and analyzed their behaviour and time spent in each environment. I found that each individual showed unique behavioural differences in the differently coloured environments. I also found an interesting pattern in the combined data for the birds...

Genetics of colour traits in common vetch (Vicia sativa L.)

Chowdhury, D.; Rathjen, J.; Tate, M.; McDonald, G.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2004 Português
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Five parents of common vetch (Vicia sativa L.) having orange/beige cotyledon colour, brown/white testa colour, purple/green seedling colour and purple/white flower colour were crossed as a full diallele set. The inheritance patterns of cotyledon, testa or seed coat colour, flower and seedling colour, were studied by analyzing their F₁, F₂, BC₁ and BC₂ generations. The segregation pattern in F₂, BC₁ and BC₂, showed that cotyledon colour was governed by a single gene with incomplete dominance and it is proposed that cotyledon colour is controlled by two allelic genes, which have been designated Ct₁ and Ct₂. Testa colour was governed by a single gene with the brown allele dominant and the recessive allele white. This gene has been given the symbol H. Two complementary genes governed both flower and seedling colours. These flower and seedling colour genes are pleiotropic and the two genes have been given the symbols S and F.; The original publication can be found at www.springerlink.com

Genomic approach to understanding variation in bovine fat colour.

Tian, Rugang
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012 Português
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Subcutaneous fat is important not only in the live animal but also in the carcass, as it prevents the rapid chilling of the underlying muscle tissues, thereby reducing weight loss during chilling. However, beef with yellow fat is considered undesirable by consumers in most European and Asian markets. Beta-carotene is the major carotenoid deposited in adipose tissue, which results in the yellowness. Genes involved in the metabolism of β-carotene in the cattle are likely to regulate beef fat colour. Therefore, DNA variants in candidate genes related to β-carotene metabolism were examined for association with beef fat colour. Based on their location in fat colour quantitative trait loci (QTL) and function in the metabolism of β-carotene, ALDH8A1, APOM, BCMO1, BCO2, RARA, RDHE2, PPARGC1A and SCARB1 were chosen as candidate genes. One hundred eleven (111) DNA variants were identified from the direct sequencing of 3 F1 sires for these eight genes, of which, 27 DNA single nucleotide polymorphisms (SNPs) were selected for association studies (3-5 SNPs per gene). Most of these genotyped SNPs and their interactions were associated with fat colour related traits (biopsy fat colour (Fc-bio), carcass fat colour (Fc-car), beta-carotene concentration (Bc-bio))...

Investigating peduncle colour evolution and chemistry during ripening in Vitis vinifera L. cv Shiraz

Fang, Yudan
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014 Português
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This thesis describes an investigation of how the various sections of the grape stem (peduncle and rachis) in Vitis vinifera L. cv Shiraz evolve in terms of their colour and chemical attributes during the ripening period and is compared to the prototypical berry ripeness parameters (⁰Brix, pH, TA, etc) over three seasons. The grape peduncles turned from green at veraison, to predominantly brown at harvest, whilst the rachises remained green during the maturation period. Certain peduncle and rachis chemical changes were also uncovered during these studies and shed light on the relationships between peduncle colour and chemical composition. Statistical modelling was conducted to examine the relationship between the peduncle colour and chemical composition, and a clear co-development was observed between peduncle evolution (colour and moisture) and the berry ripening continuum. Such observations are yet to be reported and provide for the opportunity to develop a new simple platform to assist in predicting grape berry ripeness and therefore aid in harvest decisions. Chapter 1 of this thesis comprises a detailed introduction of our current understanding on how both grape berries and their stems evolve over the ripening period and sets the scene by pinpointing key aspects for this exciting research journey. Chapter 2 details a large study on how the change in morphology (size and colour) of both the grape peduncles and rachises evolve in eight distinct patches of Shiraz from the same vineyard over two seasons. A semi-automatic method was developed to quantify the peduncle morphological details exploiting digital image analysis. The berries associated with the peduncles from the same bunches were also analysed for their prototypical berry ripeness parameters...

Korrektur von Rot- bzw. Grünanomalie mittels Farbfilter; Correction of red or green pigment anomaly by colour filter

Junger, Barbara
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
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Zielsetzung Farbensehen ist ein physiologisches Vermögen basierend unter anderem auf Pigmentgenen, erzeugten Photopigmenten und deren Absorptionsspektren. Im Falle von Störungen des Rot- und Grüngenes resultiert fehlerhaftes Farbensehen im Sinne von anomaler Trichromasie, Dichromasie oder Blauzapfenmonochromasie. Zur Therapie der anomalen Trichromasie wurden korrigierende Farbfilter (Coloryte) mit Spezialbeschichtung entwickelt, deren Einfluss auf das Farbensehen Gegenstand dieser Studie war. Methoden Mit Hilfe eines Farbsehtests (CVT) wurden die Filter individuell angepasst und daraufhin mittels sechs verschiedener Farb- und Kontrasttests (Ishiharatafeln, American Optical Hardy Rand and Rittler Test, Color vision Assessment in Diagnosis, Motion-Test und zwei verschiedene Anomaloskop-Tests) auf Veränderungen des Farbsehvermögen geprüft. Nach vollständig absolvierter Testreihe mit und ohne Filter in randomisierter Reihenfolge, konnten durch Vergleich der Ergebnisse die Filtereffekte bestimmt werden. Ergebnisse Die Ergebnisse zeigen, dass der Filteranpassungstest CVT Fehler beinhaltet, in deren Folge die Farbsehstörungsdiagnostik und damit auch die Filterzuteilung nicht korrekt funktioniert. Weiterhin zeigen die Testergebnisse nicht den gewünschten Effekt der Farbsehnormalisierung. Obwohl Protanomale teilweise von den Filtern profitiert haben...

Genetic variation in the β, β-carotene-9′, 10′-dioxygenase gene and association with fat colour in bovine adipose tissue and milk; Genetic variation in the beta, beta-carotene-9', 10'-dioxygenase gene and association with fat colour in bovine adipose tissue and milk

Tian, R.; Pitchford, W.; Morris, C.; Cullen, N.; Bottema, C.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
Relevância na Pesquisa
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beta, beta-carotene-9', 10'-dioxygenase (BCO2) plays a role in cleaving beta-carotene eccentrically, and may be involved in the control of adipose and milk colour in cattle. The bovine BCO2 gene was sequenced as a potential candidate gene for a beef fat colour QTL on chromosome (BTA) 15. A single nucleotide base change located in exon 3 causes the substitution of a stop codon (encoded by the A allele) for tryptophan(80) (encoded by the G allele) (c. 240G>A, p.Trp80stop, referred to herein as SNP W80X). Association analysis showed significant differences in subcutaneous fat colour and beta-carotene concentration amongst cattle with different BCO2 genotypes. Animals with the BCO2 AA genotype had more yellow beef fat and a higher beta-carotene concentration in adipose tissues than those with the GA or GG genotype. QTL mapping analysis with the BCO2 SNP W80X fitted as a fixed effect confirmed that this SNP is likely to represent the quantitative trait nucleotide (QTN) for the fat colour-related traits on BTA 15. Moreover, animals with the AA genotype had yellower milk colour and a higher concentration of beta-carotene in the milk.; R. Tian, W. S. Pitchford, C. A. Morris, N. G. Cullen and C. D. K. Bottema

Not so colourful after all: eggshell pigments constrain avian eggshell colour space

Hanley, D.; Grim, T.; Cassey, P.; Hauber, M.E.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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Birds' eggshells are renowned for their striking colours and varied patterns. Although often considered exceptionally diverse, we report that avian eggshell coloration, sampled here across the full phylogenetic diversity of birds, occupies only 0.08-0.10% of the avian perceivable colour space. The concentrations of the two known tetrapyrrole eggshell pigments (protoporphyrin and biliverdin) are generally poor predictors of colour, both intra- and interspecifically. Here, we show that the constrained diversity of eggshell coloration can be accurately predicted by colour mixing models based on the relative contribution of both pigments and we demonstrate that the models' predictions can be improved by accounting for the reflectance of the eggshell's calcium carbonate matrix. The establishment of these proximate links between pigmentation and colour will enable future tests of hypotheses on the functions of perceived avian eggshell colours that depend on eggshell chemistry. More generally, colour mixing models are not limited to avian eggshell colours but apply to any natural colour. Our approach illustrates how modelling can aid the understanding of constraints on phenotypic diversity.; Daniel Hanley, Tomáš Grim, Phillip Cassey and Mark E. Hauber

Functional diversity in colour vision of fish

Sabbah, Shai
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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The overall objective of this thesis was to understand better the mechanisms that shape the diversity in colour vision of fish, and to explore the adaptive significance of this divergence. Among the vertebrates, teleost fish show the greatest diversity in colour vision systems. The cichlid model system illustrates that the visual system of fish may differ among species, sexes, individuals, and life stages of individuals. The large number of available cone opsin genes, which have resulted from multiple opsin gene duplications, facilitates this high degree of variation in the mechanisms of colour vision. In general, cichlids possessed complements of four to five cone pigments, and these complements varied across species, sexes, and individuals. Additionally, lens transmission, cone pigment expression, post-receptoral sensitivity, and retinal circuitry differed across life stages of individuals. My results suggest that the diversification of colour vision across species and across life stages of individuals contributes to sensory adaptations that enhance both the contrast of zooplanktonic prey, and the detection of optical signals from conspecifics. Therefore, both natural and sexual selection may have worked in concert to shape colour vision in fish. Since light is more complex under water than on land...

Reinhardt, Martin, Richter : Colour in the Grid of Contemporary Painting

RISTVEDT, MILLY MILDRED THELMA
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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The objective of my thesis is to extend the scholarship on colour in painting by focusing on how it is employed within the structuring framework of the orthogonal grid in the paintings of three contemporary artists, Ad Reinhardt, Agnes Martin and Gerhard Richter. Form and colour are essential elements in painting, and within the “essentialist” grid painting, the presence and function of colour have not received the full discussion they deserve. Structuralist, post-structuralist and anthropological modes of critical analysis in the latter part of the twentieth century, framed by postwar disillusionment and skepticism, have contributed to the effective foreclosure of examination of metaphysical, spiritual and utopian dimensions promised by the grid and its colour earlier in the century. Artists working with the grid have explored, and continue to explore the same eternally vexing problems and mysteries of our existence, but analyses of their art are cloaked in an atmosphere and language of rationalism. Critics and scholars have devoted their attention to discussing the properties of form, giving the behavior and status of colour, as a property affecting mind and body, little mention. The position of colour deserves to be re-dressed...

SPRWeb: preserving subjective responses to website colour schemes through automatic recolouring

Flatla, David R.; Reinecke, Katharina; Gutwin, Carl; Gajos, Krzysztof Z
Fonte: ACM Press Publicador: ACM Press
Tipo: Conference Paper
Português
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Colours are an important part of user experiences on the Web. Colour schemes influence the aesthetics, first impressions and long-term engagement with websites. However, five percent of people perceive a subset of all colours because they have colour vision deficiency (CVD), resulting in an unequal and less-rich user experience on the Web. Traditionally, people with CVD have been supported by recolouring tools that improve colour differentiability, but do not consider the subjective properties of colour schemes while recolouring. To address this, we developed SPRWeb, a tool that recolours websites to preserve subjective responses and improve colour differentiability - thus enabling users with CVD to have similar online experiences. To develop SPRWeb, we extended existing models of non-CVD subjective responses to CVD, then used this extended model to steer the recolouring process. In a lab study, we found that SPRWeb did significantly better than a standard recolouring tool at preserving the temperature and naturalness of websites, while achieving similar weight and differentiability preservation. We also found that recolouring did not preserve activity, and hypothesize that visual complexity influences activity more than colour. SPRWeb is the first tool to automatically preserve the subjective and perceptual properties of website colour schemes thereby equalizing the colour-based web experience for people with CVD.; Engineering and Applied Sciences

Geographic patterns in fruit colour diversity: do leaves constrain the colour of fleshy fruits?

Burns, Kevin C.; Cazetta, Eliana; Galetti, Mauro; Valido, Alfredo; Schaefer, H. Martin
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 272132 bytes
Português
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7 pages, 2 figures.-- Supplementary material available: The list of fruit species, their colour as perceived by humans, their provenance and main disperser types. The dispersal category "mixed" refers to species consumed by birds and mammals (XLS, 43 kb).; We tested for geographic patterns in fruit colour diversity. Fruit colours are thought to promote detection by seed dispersers. Because seed dispersers differ in their spectral sensitivities, we predicted that fruit colour diversity would be higher in regions with higher seed disperser diversity (i.e. the tropics). We collected reflectance data on 232 fruiting plant species and their natural backgrounds in seven localities in Europe, North and South America, and analysed fruit colour diversity according to the visual system of birds—the primary consumer types of these fruits. We found no evidence that fruit colours are either more conspicuous or more diverse in tropical areas characterised by higher seed disperser diversity. Instead, fruit colour diversity was lowest in central Brazil, suggesting that fruit colours may be more diverse in temperate regions. Although we found little evidence for geographic variation in fruit hues, the spectral properties of fruits were positively associated with the spectral properties of backgrounds. This result implies that fruit colours may be influenced by selection on the reflectance properties of leaves...

Colour constancy in natural images through colour naming and sensor sharpening

Vázquez Corral, Javier
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf; application/pdf
Publicado em //2014 Português
Relevância na Pesquisa
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Advisors: Maria Vanrell, Graham Finlayson. Date and location of PhD thesis defense: 28 February 2011, Universitat Autònoma de Barcelona; Colour is derived from three physical properties: incident light, object reflectance and sensor sensitivities. Incident light varies under natural conditions; hence, recovering scene illuminant is an important issue in computational colour. One way to deal with this problem under calibrated conditions is by following three steps, 1) building a narrow-band sensor basis to accomplish the diagonal model, 2) building a feasible set of illuminants, and 3) defining criteria to select the best illuminant. In this work we focus on colour constancy for natural images by introducing perceptual criteria in the first and third stages. To deal with the illuminant selection step, we hypothesize that basic colour categories can be used as anchor categories to recover the best illuminant. These colour names are related to how the human visual system has evolved to encode relevant natural colour statistics. Therefore the recovered image provides the best representation of the scene labelled with the basic colour terms. We demonstrate with several experiments how this selection criterion achieves current state-of-art results in computational colour constancy. In addition to this result...

Visual evaluation of beef tenderness by using surface structural observations and its relationship to meat colour

Modika,K.Y.; Frylinck,L.; Moloto,K.W.; Strydom,P.E.; Heinze,P.H.; Webb,E.C.
Fonte: South African Journal of Animal Science Publicador: South African Journal of Animal Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 Português
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The study describes the relationship between visual and instrumental measurements for colour and tenderness between five South African beef breeds: Bos indicus (Brahman), Sanga type (Nguni), British Bos taurus (Angus), European Bos taurus (Charolais) and the composite (Bonsmara). Ten animals per genotype were used (total = 50). The carcasses were split and the right sides were electrically stimulated, while the left sides were not stimulated. Steaks were aged until three days post mortem on polystyrene plates and until 9, 14 and 20 days post mortem in vacuum bags. The steaks were evaluated by visual analysis for colour, marbling, fibre separation, surface texture and structure integrity by a 10-member trained panel. Colour was also measured by the CIE L*, a*, b* system using a Minolta meter, and tenderness was measured by means of Warner-Bratzler shear force. High negative correlations were observed between the visual colour and L* (r = -0.809), b* (r = -0.698) and high positive correlations were observed between the visual colour and hue (r = 0.797). There were also negative correlations between shear force and structure integrity (r = -0.410) and fibre separation (r = -0.401). Very low negative correlations were observed between colour and shear force (r = -0.242). Therefore...

Effect of the structure of seven anthocyanins on self-association and colour in an aqueous alcohol solution

Han,Fu Liang; Xu,Yan
Fonte: South African Journal of Enology and Viticulture Publicador: South African Journal of Enology and Viticulture
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 Português
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Anthocyanins play an important role in the colour of red wine or mulberry wine. The effect of anthocyanin structures (substitution therein) on the self-association and colour in an aqueous alcohol solution was investigated in order to provide helpful knowledge about the relationship between anthocyanin structure and colour. The addition of hydroxyl at the C3' position weakens self-association, whereas addition at the C5' position facilitates self-association. However, the hydroxyl substitutions at the C3' and C5' positions enhance colour. The methoxy substitutions at the C3' and C5' positions enhance the self-association and the colour. The replacement of glucoside with the disaccharide rutinoside at the C3 position was detrimental to self-association, but the substitution of rutinoside at the C3 position produced a stronger colour than the substitution of glucoside at the same position. Cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside enhanced colour via intramolecular co-pigmentation instead of self-association. The anthocyanin colour was affected synthetically by the types and positions of the substituent in the anthocyanin molecule.