Changes In Color Characteristics Research Articles

ВЛИЯНИЕ СКОРОСТНОГО ОБЖИГА КЕРАМИЧЕСКОГО МАТЕРИАЛА НА ОСНОВЕ ДИОКСИДА ЦИРКОНИЯ ZICERAM T ОТЕЧЕСТВЕННОГО ПРОИЗ-ВОДСТВА НА ПОКАЗАТЕЛИ ПРОЧНОСТИ И ЦВЕТА

Zirconia dentures are gradually becoming a widespread type of dental prosthetics. The production of zirconia blanks for dentistry has been launched in our country. In recent years, the possibility of high-speed sintering of zirconia dentures has been well studied, which makes it possible to reduce the manufacturing process of dental restorations by four to five times. Zirconia ceramics compositions and high-speed sintering furnaces are being improved, sintering protocols are being optimized. In this paper, we reported about the influence of high-speed firing protocols on important material`s characteristic, such as three-point bend flexural strength and color parameters at ten different heating modes, differing by heating rates, final temperature and holding time during high-speed heat treatment of ceramic material. Accord-ing to the results of bending strength tests, samples obtained with a total time of high-speed firing from 20 to 60 minutes have similar values, more than 300 MPa. In accordance with the ISO 6872 standard, such flexural strength is sufficient for fabrication of single crowns in both the anterior and posterior groups of teeth. A study on the laboratory spectrophotometer (Spectron M) in the CIELab system, showed a multidirectional change in color characteristics at different heating rates and sintering temperatures. An increase in the value of zirconia sam-ples from domestic blanks "Ziceram T" produced by St. Petersburg firm "Zircon Ceramics" was established with a sufficient confidence grade. The shortened firing time leads to an in-crease in the value of the samples, which associate with a lower translucency.

Effect of different fattening period duration on meat productivity of domestic quails

Abstract. The study was conducted with 224 domestic quails from the specialized meat-type WG line. The duration of fattening period and sex on productive traits, slaughter traits and meat quality of quails was evaluated. The study has shown that the longer duration of the fattening period in quails from the meat-type line WG was associated with lower production efficiency, with more reduction after the 35th day of life. The production efficiency in male quails was lower compared to that in females. The dispersion analysis demonstrated that the determination of 72.2% and 69.6% of dressed carcass weight and deboned meat weight, respectively, depended on fattening period duration (p<0.001). When fattening increased from 28 to 42 days, the amount of feed necessary for one bird increased by 73% and 87%, corresponding to increased costs by 64.5% and 77%. For production of 1 kg dressed quail carcasses, the necessary feed increased by 42.3-45.8% on a weight basis and by 35-37.7% on a cost basis. For production of 1 kg deboned quail meat, corresponding increases are by 42.1-49.5% and 34.8-41.2%, respectively. The period between 28 and 35 days of age was the most appropriate for planning slaughter of WG quails. During that period, the economic efficiency, although already declining, was still within acceptable limits and the increase in quantitative traits in both sexes – still relevant, making the produce more attractive for consumers. With age, the changes in colour characteristics of M. pectoralis superficialis result in darkening of meat (p<0.001). Thus, it assumes nuances specific rather for game meat. This effect is desirable, as it improves the commercial presentation of domestic quail meat in line with consumers’ attitudes.

Investigation of Color Reproduction on Linen Fabrics when Printing with Mimaki TX400-1800D Inkjet with Pigment TP250 Dyes

The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.

Низкотемпературная тепловая обработка и изменение цветовых характеристик продукции из мяса индейки

Низкотемпературная тепловая обработка и изменение цветовых характеристик продукции из мяса индейки

CHANGES OF THE OPTICAL PROPERTIES OF TOP-GRADE FLOUR (SEMOLINA) FROM DURUM WHEAT DURING ITS RIPENING

Using the rapid method of digital image analysis by the developed scanning flour analyzer the optical properties of flour (semolina) obtained in laboratory and production conditions from durum wheat of three years of harvest (2017–2019), namely the «yellowness» indicator and the color characteristic in the blue part of the spectrum, were determined. The semolina color was also evaluated by the Konica Minolta CR-410 colorimeter. It is established that the «yellowness» indicator and the color characteristic in the blue part of the spectrum did not change within the first 5 to 6 days after grinding. The change of these indicators for all the samples is observed in the period from 6 to 20 days after grinding, there with the «yellowness» indicator decreased by 25 to 40 relative units, the color characteristic in the blue part of the spectrum increased on average by 133,75 relative units. Over the next three months, there was no change of color (by both indicators). In the course of experimental work the optical properties change depending upon carotenoids content of flour (semolina) during its ripening was shown. The correlation dependence between the «yellowness» indicator of flour (semolina) and its carotenoids content is characterized by a high approximation coefficient. The dependence of the color characteristic of flour in the blue part of the spectrum on the content of carotenoids is characterized by an approximation coefficient equal to 0.9358, and is described as a polynomial equation. It shows, that with a low carotenoid content, the considered indicator is higher by an average of 1100 relative units compared to the color of samples with a carotenoid content from 0.70 to 1.21 mcg/g. At that during storage the optical properties of flour variety with the lowest carotenoids content remained practically the same. During 78 days of storage, there was no significant change of color characteristics of the industrial flour samples, studied from the eleventh day after grinding — 5–8 times higher than the average repeatability of the measurement results.

The impact of ultrasonic treatment on blueberry wine anthocyanin color and its In-vitro anti-oxidant capacity

Ultrasound (US) has been recognized as a non-thermal technology for accelerating blueberry wine aging for flavor development. However, influence of US on anthocyanin and color characteristics is uncertain. In this study, US was applied to new blueberry wine, and changes in color characteristics, anthocyanin content and anti-oxidant capacity were evaluated at early stage of aging period. Low-frequency power US resulted in an improvement in color characteristics and lower chromatic aberration as compared to untreated samples, specially at condition of 180 W, 20 min and 2 cycles. Furthermore, this contribution was attributed to unattenuated anthocyanins protected from US stress. Importantly, the structural polarity dependence was mediated by the impact of US on anthocyanins. Additionally, anti-oxidant activity of blueberry wine was not adversely affected under a moderate US condition. US treatment of blueberry wine was therefore considered to significantly enhance the color presentation, hinting at the possibility of promoting blueberry wine aging.

ДОСЛІДЖЕННЯ СВІТЛОСТІЙКОСТІ ПОФАРБУВАНЬ БАВОВНЯНОГО ТРИКОТАЖУ, ОБРОБЛЕНОГО НОВИМИ ТІОСУЛЬФОНАТНИМИ ПРЕПАРАТАМИ

Мета. Аналіз світлостійкості пофарбувань та субстрату білизняного бавовняноготрикотажу обробленого антимікробними тіосульфонатними обробними препаратамиЕТС, МТС і АТС.Методика. При дослідженнях використовували передбачені діючими державнимистандартами методи, які дозволяють визначити світлостійкість забарвлень (колірнийтон, світлість, насиченість, загальний колірний контраст) та розривальніхарактеристики бавовняних білизняних трикотажних полотен, що досліджуються. Дляоцінки світлостійкості пофарбувань, яке проводилось у лабораторії ДП «Хімтекст» (м.Херсон), використано спектрофотометр Premier Colorscan Colorlab (Spectro:5100) згідноз вимогами ДСТУ ГОСТ ІСО 105 – 701:2000 з використанням розрахункових формулсистеми CIELxaxbx.Результати. Вивчено можливість та обґрунтована доцільність використання увітчизняному текстильному та трикотажному виробництвах тіосульфонатних обробнихпрепаратів ЕТС, МТС і АТС для антимікробного оброблення бавовняних білизняних трикотажних полотен літнього асортименту з метою їх ефективного захисту відбіодеструкції целюлозоруйнуючими патогенними та ґрунтовими мікроорганізмами.Встановлено, що в процесі антимікробного оброблення бавовняних трикотажних полотенпрепаратами ЕТС, МТС і АТС не спостерігається помітних змін їх механічнихвластивостей (розривальне навантаження), що може погіршити зносостійкість тагігієнічні показники названих полотен в процесі експлуатації виробів із них. Не виявленонегативного впливу оброблення препаратами ЕТС, МТС і АТС на зміну колірниххарактеристик (світлості, насиченості, колірного тону і загального колірного контрасту)і світлостійкості пофарбувань досліджуваних трикотажних полотен кубовимибарвниками.Основною перевагою тіосульфонатних обробних препаратів є те, що їхвикористання гарантує одночасне досягнення на трикотажних бавовняних білизняних іодягових полотнах високої атмосферостійкості без погіршення їх механічнихвластивостей.Наукова новизна. В результаті проведених досліджень, встановлено, щотіосульфонатні антимікробні препарати ЕТС, МТС і АТС здатні ефективно захищатибавовняні білизняні трикотажні полотна літнього асортименту від тривалої дії сонячноїрадіації.Практична значимість. Встановлено, що обрані нами тіосульфонатні препаратиЕТС, МТС і АТС придатні не тільки для ефективного захисту від мікробіологічноїдеструкції, але й від тривалої дії світлопогоди бавовняних трикотажних полотенлітнього асортименту (робочого одягу, спортивної білизни).
 Purpose. The purpose of this work is to introduce the new types of antimicrobialpreparations to the cellulose production to provide at the same time bio-resistance, weatherresistance and environmental safety to cotton, polyester, multi-component materials. The mostdemanded creation is producing similar materials for the products of linen assortment, which aredirectly in contact with the skin, safe for human health and environment. Products from suchmaterials can be used both at home and in medical institutions, in the food industry, in trains oflong-distance trafficking, in the army, etc.A lot of attention all over the world is paid for the development of various methods forobtaining and studying the properties of materials with antiseptic attributes. However, despite thelarge amount of work in this area, many issues are still far from their solution. In particular, the actual task is to create environmentally friendly textile materials and knitted cloths withantimicrobial properties, which are stored in wet treatments, washing, light exposure, that isnecessary in using underwear in real conditions. The problems associated with reducing the costto obtain such materials are equally important. Therefore, the purpose of our research is toanalyze the light-fastness of paints and the substrate of linen cotton knitted fabrics treated withantimicrobial thiosulfonate preparations of ETS, MTS and ATS.Method. The methods provided in applicable state standards that determine the lightnessof colors (color tone, lightness, saturation, overall color contrast) and the breakingcharacteristics of the cotton linen fabrics were used in the studies.Results. The possibility and feasibility of using thiosulonate preparations including ETS,MTS and ATS in the domestic textile and knitwear production for antimicrobial treatment ofcotton linen knitted cloths of the summer range for the purpose of their effective protectionagainst biodestruction by cellulose-destroying pathogenic and soil microorganisms aresubstantiated.In the process of antimicrobial treatment of the studied cotton knitted fabrics by ETS, MTSand ATS preparations, no noticeable changes in their mechanical (breaking strength) propertiesare observed, which may worsen the wear resistance and hygienic performance of these fabricsduring the operation of products from them.No negative influence of treatment with ETS, MTS and ATS preparations on the change ofcolor characteristics (lightness, saturation, color tone and general color contrast) and lightstability of coloring of studied knitted fabrics by cubic dyes was found.The main advantage of thiosulfonate treatments is that their use guarantees simultaneousachievement on knitted cotton linen and clothing cloths of high atmospheric resistance withoutdegradation of their mechanical properties.Scientific novelty. As a result of the research, thiosulfonate antimicrobial preparationsincluding ETS, MTS and ATS are found to able to effectively protect the cotton linen knitted linenof the summer range from prolonged exposure to solar radiation.Practical significance. The thiosulfonate preparations chosen by us, such as ETS, MTSand ATS, are revealed to suitable not only for effective protection against microbiologicaldestruction, but also from the long-lasting effect of light clothing of cotton knitted linen of summerassortment (working clothes, sportswear).

Reversible and Irreversible Color Change during Photo and Thermal Degradation of PolyphenyleneSulfide Composite.

The effect of the light spectral composition and temperature on the change of color characteristics and reflection spectra during the irradiation of polyphenylene sulfide reinforced by short glass fibers in the SUNTEST apparatus was analyzed. The scales of reversible color change upon successive exposure to total radiation corresponding to the sunlight spectrum and to visible light wereevaluated and the possible mechanisms for the observed effects are discussed. The features of the color change upon visible light irradiation of previously thermally aged samples wereconsidered. Possible causes for deviation from the Arrhenius law during thermal aging of the composite are discussed. It wasdemonstrated that even with a significant change in color, the physicomechanical and electrotechnical characteristics of the composite only changedslightly or remained virtually at the same high level.

Quality stability of clear pomegranate juice treated with cyclodextrin.

Protective effect of cyclodextrin (CD) on some quality characteristics of clear pomegranate juice (CPJ) was investigated. CPJ with no CD addition (Control) and CPJ samples, subjected to different type (β-CD and Hydroxy propyl (HP-β-CD) and concentration (0.5, 1% and 2%) combinations of CD, were stored at 25°C for 3months. The changes in color characteristics (polymeric color and total color difference - ΔE), total phenolic content (TPC) and antioxidant activity (AA) of all PJ samples monitored at 1month intervals. Although overall color change of the PJ samples was hardly perceived visually, none of the treatments were successful to protect the initial color of clear PJ technically (P > 0.05). Among the CD treatments, HP-β-CD with a concentration of 0.5% was found effective to prevent TPC and AA losses of PJ (P < 0.05). On the other hand, β-CD addition did not cause any improvement in protecting color, TPC and AA of clear PJ during storage, compared to control juice.

Effect of washing cycles and solutions on chemical composition and physicochemical properties of the surimi‐like material from mechanically deboned turkey meat

The effects of washing solutions and number of cycles on mechanically deboned turkey meat (MDTM) were evaluated for the production of surimi-like material (SLM) using water, sodium chloride, sodium bicarbonate, and potassium phosphate buffer. Yields vary from a low of 30.98% with sodium chloride solution to as high as 37.33% with sodium bicarbonate. Chemical composition of washed samples showed moisture content of 75.46%–79.52%, fat at 5.87%–7.14%, protein at 12.35%–15.36%, and ash at 0.81%–1.29%. Repeated washings resulted in reduce in soluble proteins. Washing with sodium bicarbonate increased sodium content of unwashed MDTM from 60.76 mg/100 g to 109.41 mg/100 g, while water and phosphate buffer decreased it to 5.33 mg/100 g and 7.95 mg/100 g. SLM washed with sodium bicarbonate had higher pH and water holding capacity, and showed better changes in color characteristics than unwashed MDTM and other SLMs. This study demonstrates that sodium bicarbonate solution provided a desirable SLM with best technological quality. Practical applications MDTM is widely used by the Brazilian industry in the production of meat products, in which the use of up to 60% of the product is allowed. However, in products with a low fat content and with light color characteristics, such as some cured cooked poultry, the use of MDTM is limited precisely because it contains high content of fats and heme pigments. Washing process is one of a practical method to produce SLM resulting in higher myofibrillar proteins concentration and lower fat and heme pigments. However, different washing solutions and multiple washes provide different qualities of SLM from different species. Thus, determining the optimal washing process and its effects on the SLM characteristics is important for its application in meat products with low fat and with less pigmentation. Due to its properties, all types of SLM had potential applications for meat replacer in the production of emulsified and restructured meat products, with emphasis on the SLM obtained by use of sodium bicarbonate washing solution.

Color measurements of composite materials for tooth restoration in standardized in vitro conditions

A national standard GOST R 58165-2018 (ISO/TR 28642:2016) 'Dentistry - Guidance on colour measurement' has been developed based on the international document which establishes standardized conditions for carrying out laboratory methods of measuring color by visual and instrumental methods. In vitro tests of samples of FiltekTM Ultimate, FiltekTMZ250 and Premise on the acoustooptic color analyzer SPEKTRON-M (FGUP 'VNIIOFI', Russia) in accordance with the recommendations of the standard GOST R 58165-2018 (ISO/TR 28642:2016) allowed to determine the effect of the shelf life of paste composite materials on the aesthetic indicators: colour compatibility, colour stability after aging and degree of transparency. The greatest changes in color characteristics in the CIELAB system during the storage of pastes were noted for the Premise Kerr A2 Enamel and A3 dentin composites. The greatest color change after exposure in water at 37 ° C was established for FiltekTMZ250 A4 samples with a long shelf life of the composite resin, ΔE=3.92>2.7 (p=0.001), but the color resistance of samples of the same composite from a new batch after exposure in water corresponds to the requirements of the standard, ΔE=2,18<2,7 (p=0,001).

THE STUDY OF ODOR PROFILE AND COLOR CHARACTERISTICS IN BEEF DURING HEAT TREATMENT

The article presents the study results of changes in the odor profile and color characteristics in beef under various heat treatment conditions. More than 120 volatile substances are identified. In samples subjected to short-term and minor heat treatment, 2-methyl-butene and ethyl hexanoate were found in significant amounts. In samples subjected to prolonged roasting at low temperature, as well as in samples subjected to processing at higher temperature for less time period, was found 3,5-dimethyl–4-octanone. Analysis of changes in color characteristics showed that increase in heating temperature results in significant darkening of the samples. The maximum heating temperature of 210 °C had the most significant effect on the color change. After heating for more than 30 minutes, carbonization of the samples occurred. The results indicate that controlling the temperature and duration of heat treatment helps to obtain the finished product of desired color.

Application of atmospheric cold plasma-activated water (PAW) ice for preservation of shrimps (Metapenaeus ensis)

In this paper, plasma-activated water (PAW) ice is proposed for the preservation of fresh shrimps. The changes in microbiological, physical, chemical and protein properties were investigated during storage with conventional tap water (TW) ice and PAW ice. Compared with TW ice, PAW ice showed significant advantage for inhibition of microbial growth, extending the storage time by 4–8 days. The pH of shrimps treated with PAW ice remained below 7.7 during storage. The deteriorating changes in color characteristics and hardness were delayed by the PAW ice treatment. The production of volatile basic nitrogen (TVBN) was reduced to below 20 mg/100 g during PAW ice storage, significantly lower (p < 0.05) than that of the samples treated with TW ice. In addition, PAW ice did not result in adverse changes in shrimp proteins. Therefore, the study showed that PAW ice may be used in preservation of fresh seafood.

Effect of corona discharge plasma on microbial decontamination of dried squid shreds including physico-chemical and sensory evaluation

Non-thermal techniques for microbial decontamination in foods are becoming more promising. This work aims to evaluate the suitability and effectiveness of corona discharge plasma jet (CDPJ) for the inactivation of microbial contaminants of dried squid shreds. CDPJ was generated using 20 kV pulsed DC voltage and at a 58 kHz frequency. Upon the CDPJ treatment (0–3 min) of dried shreds, contaminants namely aerobic bacteria, marine bacteria and Staphylococcus aureus were inactivated by 2.0, 1.6, and 0.9 log units, respectively. Also, a 0.9 log reduction of yeasts and molds contaminants was observed. The inactivation pattern fitted well to the pseudo-first-order model rather than first-order kinetic model. The CDPJ treatment did not exert statistically significant (P > 0.05) changes in color characteristics and volatile basic nitrogen content of dried squid shreds as compared with untreated controls. In contrast, the moisture and thiobarbituric acid reactive substances levels of shreds were significantly (P < 0.05) altered by the plasma exposure. However, the treatment exerted no significant (P > 0.05) impact on the sensory characteristics of dried squid shreds. The CDPJ was found to be effective for microbial decontamination of real-world samples of dried squid. This technology can readily be applied to commercial dried squid processing.

Effect of low-pressure air plasma on the microbial load and physicochemical characteristics of dried laver

Low-pressure air plasma (LPAP) has not been widely used for food products surface bio-decontamination. In the present study, LPAP was used as inactivating agent against surface microbial contaminants of sun-dried laver sheets. Microbial inactivation kinetics and physicochemical characteristics of LPAP-exposed laver sheets were determined. Also, the sensory properties of kimbab (rice rolled in laver), which was roll wrapped using plasma-treated dried laver, were evaluated. LPAP was generated at the vacuum pressure of 133.3 Pa or 1Torr, and a power density of 54.1 mW/cm3. Upon LPAP-exposure, over 1-log reduction in viable cell count of aerobic bacteria was observed over a 20 min period. The microbial inactivation pattern fitted well to Singh-Heldman model or pseudo-first-order kinetics. Compared to plasma-unexposed laver, there were no changes in color characteristics, total phenolic content, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of plasma-exposed laver. Furthermore, the use of LPAP-exposed laver sheets exerted minimal to no impact on sensory characteristics of kimbab.

Microbial decontamination of dried laver using corona discharge plasma jet (CDPJ)

In the present study, atmospheric pressure corona discharge plasma jet (CDPJ) was used for surface microbial decontamination of thin sheets of dried laver, which is commonly used in ready-to-eat Korean rice roll, gimbap (kimbab). Microbial contaminants namely aerobic bacteria, molds, and marine bacteria were found on the surface of commercial dried laver sheets. CDPJ was generated at an output voltage of 20kV DC and frequency of 58kHz. Upon exposure to the CDPJ, greater than 2 log (99%) unit reductions in viable cell count of aerobic bacteria was observed over a 20min period. The inactivation pattern fitted well to Singh–Heldman model or pseudo-first order kinetics. Compared to plasma-unexposed laver, no changes in color characteristics, total phenolic content and DPPH radical scavenging activity were observed in plasma-exposed laver. Furthermore, CDPJ-exposed laver sheets had exerted minimal to no impact on sensory characteristics of gimbap (kimbab), while extending the shelf life of the product. In conclusion, CDPJ can be used for surface decontamination of dried laver without adversely affecting its physical as well as functional properties.

Changes in the Reflectivity and Color Characteristics of Microcellular Foamed Plastics

As the use of plastics has increased in various industries, research on microcellular plastics has increased as well. The microcellular foaming process helps produce lighter plastic and reduces material consumption. This process also affects the optical properties. The primary purpose of this study is to measure the visible changes occurring in polymer samples by comparing changes in the samples before and after the microcellular foaming process. To measure the changes in color characteristics, colored PC samples were utilized for the experiments. Changes in the color characteristics were indicated using the Munsell color system.

Effects of humic substances supplementation provided through drinking water on performance, carcass traits and meat quality of broilers

The present study aimed at evaluating the effects of different doses of humic substances (HS) in waterer pan on broiler performances and meat quality. For the trial, 480 chicks (ROSS 308) were allocated into four groups (HS0, HS150, HS300 and HS450) of 120 equally mixed-sex birds, each receiving a drinking water supplemented with 0, 150, 300 and 450 ppm of a humic acid (provided by 0.0%, 0.5%, 1.0% and 1.5% of HS, v/v) respectively. At the age of 21 and 42 days, feed consumption and live weight were taken. At the age of 42 days, 16 birds per treatment were slaughtered, dressing percentages, digestive tract traits were evaluated and samples of breast (pectoralis major) and thigh (iliotibialis) meat were taken to evaluate the changes in colour characteristics (CIE L*, a* and b*) and chemical composition. The body weight gain increased by the HS300 in relation to the HS0 and HS450, and decreased by the HS450 in relation to the HS0. The feed consumption of birds in the HS450 and feed efficiency of birds in the HS300 were lower and higher than those in the other treatments respectively. The carcass weight of broilers in the HS150 and HS300 were higher than those of in the HS0 and HS450. The carcass weight decreased by the HS450 in relation to the other treatments. The dressing percentage increased by the HS150 in relation to the HS450. The HS450 resulted in breast and thigh meat colour that were lighter than those found in the HS0 birds. The HS450 increased fat content of thigh meat in relation to the HS0. It was concluded that the humic acid supplementation at 300 ppm and 450 ppm appears to have a measurable impact on live performance improving feed efficiency and lightness of breast and thigh meat colours in broilers respectively.

Segmentation of small objects in color images

A method for effective segmentation of small objects in color images is presented. It can be used jointly with region growing algorithms. Segmentation of small objects in color images is a difficult problem because their boundaries are close to each other. The proposed algorithm accurately determines the location of the boundary points of closely located small objects and finds the skeletons (seed regions) of those objects. The method makes use of conditions obtained by analyzing the change of color characteristics of the edge pixels along the direction that is orthogonal to the boundaries of adjacent objects. These conditions are generalized for the case of the well-known class of color images having misregistration artifacts. If high-quality seed regions are available, the final segmentation can be performed using one of the region growing methods. The segmentation algorithm based on the proposed method was tested using a large number of color images, and it proved to be very efficient.

Changes in colour characteristics and pigmentation of subcutaneous adipose tissue and M. longissimus dorsi of heifers fed grass, grass silage or concentrate-based diets

The objective of this experiment was to determine the effect of dietary composition and duration of feeding on subcutaneous (s.c.) adipose tissue and M. longissimus dorsi (LD) colour and pigment concentrations of heifers. Fifteen heifers were permanently housed and fed a concentrate diet (PH-CON). Fifty-four heifers were grazed on pasture (PAS) for 90d, housed and offered concentrates (PAS-CON), 200 g grass silage (GS)/kg dry matter (DM) (PAS-GS20), 500 g GS/kgDM (PAS-GS50) or zero-grazed grass (PAS-GRA). To facilitate assessment of the temporal pattern of tissue colour, 3 heifers/treatment were slaughtered at housing (following 7d adjustment to diets) and 28, 56, 91 and 120 days thereafter. Yellowness (‘ b’ value) of s.c. adipose tissue and lightness (‘ L’ value) and redness (‘ a’ value) of LD were recorded 48 h post-mortem. β-Carotene and lutein contents of s.c. adipose tissue and total LD haem pigments were determined. At housing, s.c. adipose tissue ‘ b’ values of the PAS group (mean = 13.47) were higher ( P < 0.01) than those of the PH-CON group (mean = 10.35) but there was no difference in β-carotene or lutein concentrations. The change in s.c. adipose tissue ‘ b’ for each diet following housing was best described by the following equations: PH-CON: y = −0.087 (SE 0.0347) X + 0.0005 (SE 0.00029) X 2 + 10.06 (SE 0.600), MSE 1.94, R 2 0.57, P < 0.01. PAS-CON: y = −0.102 (SE 0.0286) X + 0.0006 (SE 0.00024) X 2 + 13.32 (SE 0.598), MSE 2.30, R 2 0.62, P < 0.001. PAS-GS20: y = −0.106 (SE 0.0296) X + 0.0008 (SE 0.00025) X 2 + 13.10 (SE 0.618), MSE 2.46, R 2 0.47, P < 0.01. PAS-GS50: y = −0.077 (SE 0.0269) X + 0.0006 (SE 0.00023) X 2 + 13.29 (SE 0.552) MSE 1.95, R 2 0.38, P < 0.05. PAS-GRA: y = −0.018 (SE 0.0079) X + 13.77 (SE 0.528), MSE 2.28, R 2 0.24, P < 0.05, where y = ‘ b’ value, x = days post-housing (d96–d216) and MSE = mean square error. Treatment had a significant effect on s.c. adipose tissue β-carotene and lutein (both P < 0.001) with PAS-GRA and PH-CON tending to have the highest and lowest concentrations, respectively. PH-CON heifers tended ( P = 0.058) to have lower LD haem pigments and lighter LD than other heifers. It is concluded that, while concentrate feeding led to the greatest decrease in s.c. adipose tissue yellowness relative to PAS-GRA, choice of dietary ingredients and duration of feeding will depend on the stringency of the colour criteria in particular markets.