Chromatic Changes Research Articles

Polydiacetylene (PDA) Film: A unique sensing element

Polydiacetylene (PDA) Langmuir films consist in two structural and chromic phases: metastable, non-fluorescent blue phase and stable, auto-fluorescent red phase. They are promising material for developing sensor with their fluorescence/colorimetric dual response. The blue PDA film when exposed to analyte of interest, shows a chromatic change to red phase, is utilised to detect sensor array. PDA molecules form a stable trilayer on maximum compression and after UV polymerization they are transferred to solid substrate.

Effect of sucrose concentration and pH onto the physical stability of β-carotene nanocapsules

The incorporation of β-carotene into foods has a great impact due to its important biological properties and characteristic orange color that is of great interest for applications that require a natural colorant. However, it has limitations because of its lipophilic nature. Given this problem, an effective alternative is incorporating it as a functional ingredient in nanoencapsulation form, since this presents a significant benefit compared to emulsions/nanoemulsions; namely, increased solubility in aqueous media. In this study, the physical stability of dispersions was evaluated in relation to three factors: pH, sucrose concentration and different concentrations of β-carotene nanocapsules. Samples were characterized in terms of morphology, particle size, zeta potential, colorimetry, turbidity, and diffuse reflectance. Results show that no significant aggregation was detected, as revealed by turbidity (τ∼cte) and diffuse reflectance (p > 0.05), but that significant changes in chromaticity did occur during the storage period (p < 0.05) in all samples analyzed. The particle size obtained during monitoring was always below 300 nm. Minimal changes in zeta potential in the samples was evaluated. Given that these β-carotene nanocapsules showed only minimal changes in physical stability during storage, they may represent an effective option as a component of functional beverages and foods, as well as nutraceutical products.

Weathering resistance of PMMA/SiO2/ZrO2 hybrid coatings for sandstone conservation

Accelerated weathering of polymethylmethacrylate (PMMA) and of hybrid PMMA/SiO2/ZrO2 films was monitored by spectroscopic, thermal and colorimetric measurements. The hybrid polymers were obtained by sol-gel process adding tetraethylorthosilicate (TEOS) and zirconyl chloride (ZrOCl2*8H2O) to a solution of PMMA. Photo ageing tests on polymeric films under artificial sunlight irradiation in a climatic chamber suggest that the addition of the inorganic fillers slows down the chemical degradation of PMMA. The polymers were deposited on two different sandstones from Tuscany (Italy): Pietra Dorata and Pietra Serena. Capillary water absorption, contact angle and color measurements show that the hybrid-PMMA coatings retain the water repellency of the sandstone and do not introduce noticeable changes of the aesthetic appearance. Accelerated weathering of the treated sandstone confirms that the SiO2/ZrO2 inorganic filler delays the chromatic changes of the polymer.The hybrid coating may then be proposed for application in the field of outdoor conservation of sandstones, used as building material in ancient and modern architectures.

영화에서 표현된 색채의 특성과 내러티브의 연관성에 관한 분석

Since the first appearance of color film in the late nineteenth Century, the amount of information carried by color films has been increasing day by day, and color has gradually become part of the basic concept of the film. Numerous film researchers and psychologists have added a variety of definitions of colors which have become an indispensable expression of the film. When watching movies, viewers will be affected by changes in lightness and chroma of color in different scenarios. The right use of color can arouse various associations of human life experiences, and certain colors have certain symbolic meanings. The purpose of this thesis is to understand the symbolism and character of color in the film and its relevance to the plot. And to study the implication of colors in human senses and the effect in the film arts. In this connection, the thesis analyzes the symbolic meaning of color in film, and scenarios directed by David Lynch as the research object, analyzes the effect of various colors’lightness and chroma on colors’symbolic value and the correlation between the performance of the color and the relevance of the story. Through these analyses, it can be found that, in David Lynchs films, lightness and chroma are closely related to the plot of the movie Therefore, we can see that the color is indeed symbolic and has an impact on the film plot.

Real-time monitoring of organic apple (var. Gala) during hot-air drying using near-infrared spectroscopy

Dried apple (Malus domestica B.) shows a growing trend to its worldwide consumption as raw material used to produce organic snacks, integral breakfast foods, chips, etc. Apple is often dried by conventional methods (e.g. hot-air drying, freeze-drying, etc.), which are usually uncontrolled and then prone to product quality deterioration. Thus, to allow the production of high-value end products, there is a need for developing new drying systems. In this study, it was investigated the feasibility of an implementation of NIR spectroscopy in smart drying systems to non-destructively detect and monitor physicochemical changes in organic apples wedges during 8-h hot-air drying at 60 °C. Moreover, the impact of microwave heating pre-treatment (at 850 W for 45 s) as enzyme inactivators on model performances was also evaluated. Partial least squares (PLS) regression models were successfully developed to monitor changes in water activity (R2 = 0.97–0.98), moisture content (R2 = 0.97–0.98), SSC (R2 = 0.96–0.97) and chroma (R2 = 0.77–0.86) during drying. Classification analysis was performed for the development of discriminant models able to recognise dehydration phases of apple wedges on the basis of their spectral profile. The classification models were computed using K-means and Partial Least Squares Discriminant Analysis (PLS-DA) algorithms in sequence. The performance of each PLS-DA model was defined based on its accuracy, sensitivity and specificity rates. All of the selected models provided a very-good (>0.90) or excellent (>0.95) sensitivity and specificity rates for the predefined drying phases. Feature selection procedures allowed to obtain both regression and classification models with performances very similar to models computed from the full spectrum. Results suggest that effect of microwave heating on both water loss and microstructure of apple tissue was pronounced, mainly affecting the features selection procedure in terms of number of features and selected wavelengths.

Optical properties of densified phosphor-in-glass LED encapsulants by spark plasma sintering

Phosphor-in-glass (PIG) has recently been receiving attention for use in light emitting diode encapsulants because of the remarkable chemical and mechanical properties of the resulting encapsulants. The PIG plate, however, contains pores that interact with the light and lead to changes in transmittance and chromaticity of the plate. In this study, therefore, PIG was sintered via spark plasma sintering (SPS) to reduce the number of pores via the densification process, and the factors for improving the luminous efficacy of PIG were confirmed by analyzing the pore size and scattering coefficient. The luminous efficacy and color rendering index were dramatically improved in all of the PIG samples subjected to SPS. The purpose of this study is to reduce the pores and improve the optical properties of PIG via the densification process. Further, it also aims to understand the effect of the pores on the increase in the efficacy of the PIGs based on the scattering events.

Chemical composition of felt-tip pen inks.

Felt-tip pens are frequently used for the realization of sketches, drawings, architectural projects, and other technical designs. The formulations of these inks are usually rather complex and may be associated to those of modern paint materials where, next to the binding medium and pigments/dyes, solvents, fillers, emulsifiers, antioxidants, plasticizers, light stabilizers, biocides, and so on are commonly added. Felt-tip pen inks are extremely sensitive to degradation and especially exposure to light may cause chromatic changes and fading. In this study, we report on the complete chemical characterization of modern felt-tip pen inks that are commercially available and commonly used for the realization of artworks. Three brands of felt-tip pens (Faber-Castell, Edding, and Stabilo) were investigated with complementary analytical techniques such as thin-layer chromatography (TLC), VIS-reflectance spectroscopy, μ-Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), GC-MS, and Fourier transform infrared (FTIR) spectroscopy. The use of TLC proved to be very powerful in the study of complex mixtures of synthetic dyes. First derivatives of the reflectance spectra acquired on the TLC spots were useful in the preliminary identification of the dye, followed by Raman spectroscopy and SERS, which allowed for the unambiguous determination of the chemical composition of the pigments (phthalocyanines, dioxazines, and azo pigments) and dyes (azo dyes, triarylmethanes, xanthenes). FTIR spectroscopy was used especially for the detection of additives, as well as for confirming the nature of solvents and dyes/pigments. Finally, (Py-)GC-MS data provided information on the binders (styrene-acrylic resins, plant gums), solvents, and additives, as well as on pigments and dyes.

Use of hyperspectral imaging for the prediction of moisture content and chromaticity of raw and pretreated apple slices during convection drying

ABSTRACTThe feasibility of using spectral reflectance information in the visible—near infrared (400–1,000 nm) region to estimate moisture content (gW/gDM) and chromaticity (CIELAB) of apple slices was investigated during convection drying. Apple slices were pretreated with hot water blanching (50 and 70°C), acid application (citric and ascorbic), and combinations thereof before drying at 50 and 70°C. Prediction models for the space-averaged spectral reflectance curves were built using the partial least square regression method. A three-component partial least square regression (PLSR) model satisfied the minimal root mean square error (RMSE) criterion for predicting moisture content (avg. RMSEP = 0.13, r2 = 0.99); importantly, the critical wavelengths remained the same across all pretreatments (540, 817, 977 nm). Similarly, PLSR modeling showed that the optimal set of wavelengths (in terms of RMSE) were invariant across pretreatment for CIELAB a* prediction (543, 966 nm) and CIELAB b* prediction (510, 664, 714, 914, 969 nm). The stability of the information content of these wavelengths across pretreatments indicates their independence of color changes. Additionally, the spatial information in the hyperspectral images was exploited to visualize the performance of the predictive models by pseudo-coloring their values for each pixel in a single apple slice across different drying times. This visualization of spatial distribution of predicted moisture content and chromaticity changes shows significant potential for use in online monitoring of the drying process.

Ratiometric fluorescent sensing of copper ion based on chromaticity change strategy.

Copper ions play a significant role in human bodies, as they are beneficial for many metabolism processes, but excessive Cu2+ may cause various symptoms. Therefore, the development of strategies capable of both sensitive detection and visualization of Cu2+ is greatly important for human health. In this work, a novel ratiometric fluorescence sensor for rapid and visual detection of Cu2+ was designed based on green emission carbon dots (CDs) and red emission CdTe/CdS quantum dots (QDs). We have calculated the chromaticity coordinates of individual CDs and CdTe/CdS QDs, and the chromaticity coordinate of their mixture would change along the line between the two points of CDs and CdTe/CdS QDs in the chromaticity coordinate system. The red fluorescence of QDs can be influenced by Cu2+, and the fluorescence color of CDs-QDs changes from yellow to green as the chromaticity coordinates change with the addition of Cu2+. This traffic-light-type color change was more sensitive to the naked eye compared to conventional single emission-based sensors. This paper not only realized ratiometric fluorescence and visual detection of Cu2+ through a convenient method but also provided a promising strategy of designing an assay kit for trace Cu2+. Graphical abstract Ratiometric fluorescent sensing of copper ion based on chromaticity change strategy.

تقییم بعض اللواصق المستخدمة فی تجمیع الآثار الفخاریة المستخرجة من حفائر تل آثار الفضة بسیناء فی ضوء نسیجها الفخاری: دراسة تجریبیة.

إن الفخار الأثري المستخرج من تل آثار الفضة بسيناء يعاني من ظاهرة الکسر Breaking، ومثل هذه النوعية تحتاج إلي عمليات تجميع بأحد مواد اللصق حيث تعد من أهم عمليات الترميم والصيانة. وتم فحص وتحليل العينات الفخارية بتل الفضة بسيناء باستخدام الفحص بالميکروسکوب المستقطبPolarized والفحص والتحليل باستخدام الميکروسکوب الإلکتروني الماسح Scanning Electron Microscopeالمزود بوحدة تشتت طاقة الأشعة السينية وکذلک التحليل بحيود الأشعة السينية بطريقة المسحوق X- Ray Diffractionبغرض التعرف علي نسيج الفخار الأثري ومعدل تلفه لإختيار المادة اللاصقة وفقا للنسيج الفخاري. وتم إعداد عينات فخارية مصنعة من طفلة الموقع الأثري، وکذلک عينات من مواد اللصق المختارة مثل البارالويد Paraloid B82والموليثMowilith DS 5 أسيتات الفينيلوأسترات البيوتيل لحمض الماليک والبريمال Primal AC33 والأوهو بلس UHU Plus من الأيبوکسي والبولي فينيل أسيتاتPoly Vinyl Acetate والأيبو نوع من الأيبوکسي والأکريل Micro Acrylic لاستخدامها في الدراسة التجريبية، وأجريت علي عينات مواد اللصق المختارة العديد من عمليات التقادم الصناعي والاختبارات والفحوص المختلفة مثل: الفحص العيني والمجهري وقياس التغير اللوني وقوة الشد بغرض تقييم اللواصق المختارة. ولقد أثبتت الفحوص المختلفة أن نسيج فخار تل الفضة بسيناء من الطين النيليNile Clay –B، ونسيج الفخار المستورد بتل الفضة من نوع الطين الجيري Marl Clay –D، وهو يعاني من التشوه السطحي والکسر وتبلور الاملاح. کما أثبت البحث نجاح وکفاءة لاصق البارالويد ب82 الذائب في الترايکلوروايثيلين بترکي50 % أو الأکريل في تجميع الفخار المحلي Clay fabric، ولاصق الأيبو 150 في تجميع الفخار المستورد Fabric Marl Clayلقدرتهما في تحسين خاصية قوة الشد Tensile Strength، ومقاومة التقادم الصناعي مقارنة بباقي مواد اللصق الأخري، ويوصي البحث بضرورة استخدام أحد تلک اللواصق في تجميع الفخار المستخرج من تل الفضة بسيناء. Archaeological pottery at Tel El-fada in Sinai suffered of breaking phenomenon, this pottery required assembling process by one of the adhesive materials, it is one of the most important restoration and maintenance processes. Some pottery samples in Tel El-fada in Sinaiwere examined and analyzed using Polarized Microscope PLM, Scanning Electron with Energy Dispersive of X-Ray Unit SEM- EDX and X-ray diffraction analysis XRD to identify fabric pottery and its damage for selecting appropriate adhesive. Many manufactured pottery samples were prepared, andalso some selected adhesives samples such as Paraloid B82, Mowilith DS , Primal AC33, UHU plus, Poly Vinyl Acetate, Epo 150 and micro Acrylic Emulsion were prepared for use in experimental study. Some selected adhesives samples were conducted many artificial ageing, various tests, experiments, examinations such as visual examination, stereo-microscope, measurement of chromatic change and tensile strength for evaluating selected adhesives. Various examinations had proved that pottery fabric in Tel El-fada in Sinai was Nile clay B fabric and the imported pottery in Tel El-fada was marl clay D fabric,they suffered from surface deformation, breaking and crystallization of salts. The research also demonstrated the success and efficiency of Paraloid B 82, concentration 50% or micro acrylic emulsion ME for Nile clay fabric and Epo 150 for marl clay fabric, being improved Tensile Strength Property, and high resistance to thermal and light accelerated artificial ageing compared to the rest of the other adhesives. The research recommends that one of these adhesives should be used to assemble pottery in Tel El-fada in Sinai.

Chromatic changes in the broccoli stored under modified packaging

Broccoli was stored under modified atmosphere packaging (MAP) at 15°C in perforated and non perforated low density polyethylene (LDPE) and polypropylene (PP) films packages having different head space and in un-sealed packages for a storage period of 10 days to evaluate the effect of modified atmospheres on chromatic changes. At the end of storage, MAP resulted in differential changes in the original green color of broccoli under different packaging treatments. Instead of conventional CIELAB color space system utilizing L*, a* and b* value, the chromatic changes were analyzed as per L*C*h* colour space system using lightness, chroma, and hue angle values to evaluate final hue (color) along with its associated attributes. On 10 th day the result showed that LDPE retained better color than PP films. In non-perforated, the sample become anaerobic after 24 hr. Overall at the end of storage, perforated LDPE package having more head space controlled the colour change within human acceptable limits. In comparison, the unsealed packages turned orange yellow compared to MAP. Also the results of sensory evaluation and visual analysis confirmed the results obtained from L*C*h* color space diagram, and indicated that the modified atmosphere (6.0% O 2 and 7.8% CO 2 ) generated inside the LDPE perforated packages having 2 holes and 0.8 head space was suitable in maintaining the chromatic quality of the broccoli heads.

파장변화에 매우 안정한 시준렌즈 설계

특정한 파장대역에서 파장변화에 따른 굴절능의 변화를 1차, 2차 미분까지 보정하여 기준파장과 그 인근 파장 대역에서 굴절능의 변화가 매우 적도록 안정화된 광학계를 설계하는 방법에 대하여 연구하고, 이를 적용하여 회절한계의 시준렌즈를 설계하였다. 설계된 광학계는 파장 변화에 대하여 매우 안정하였고, 파장 360~410 nm 대역에서 유효초점거리의 변화가 0.002% 이내로 매우 적었다. To minimize chromatic variations across a wavelength band, we suggest a new design that corrects the first- and second-order wavelength derivatives of the refractive power. Based on this method, a diffraction-limited collimator is designed. The design is very stable against wavelength change, as expected. The chromatic change of the effective focal length is less than 0.002% in the wavelength range from 360 to 410 nm.

Permeation-induced chromatic change of a polydiacetylene vesicle with nonionic surfactant

A color change could be achieved by substrate permeation in a polydiacetylene vesicle formed with nonionic surfactant. The polydiacetylene vesicle was formed with N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA), tetra(ethylene glycol) monooctadecyl ether (TEGOE) was used as a nonionic surfactant, and methotrexate (MTX) was used as a substrate. The color change from blue to red due to MTX permeation was clearly shown when the AEPCDA: TEGOE ratio was 4:6. The change in color occurred only with the mixed vesicle with TEGOE. The change color could occur through permeation of a substrate with a high molecular weight, for example gentamicin and neomycin, but it could not occur with a substrate with low molecular weight, for example ethylamine and butylamine.

Effectiveness of Different Mordants and Concentrations on the Dyeing Properties of Jackfruit (Atrocarpus heterophyllus) Bark on Silk

A study was carried out to assess the effect of different mordants and concentrations on the colouring characteristics of jackfruit bark dye on silk. Six types of mordants, viz. citric acid, alum, ferrous sulphate, aluminum sulphate, copper sulphate and potassium dichromate (K2Cr2O7) were used, each at 1, 2 and 3% of weight of the fabric (o.w.f.). The material liquor ratio was maintained at 1: 40. The Hunterlab colour scale was used to analyse the variations in colour and intensities. The results indicated that the maximum change in colour with respect to the undyed silk fabrics was for 2% alum treated samples with the ΔE* value of 27.08±0.29. However, the values were not significantly different from the samples treated with FeSO4 mordant at 2% and 3% levels, CuSO4 mordant at 2% level and alum at 3% level. The change in chroma (ΔC*) value was maximum for the alum (2%) mordant (24.44±0.2). The analysis on colour fastness with respect to washing, rubbing and sunlight also indicated that all mordants and concentrations used in the study excepting 1% alum offered adequate fastness characteristics. The unmordanted samples exhibited moderate fastness. In view of the colour fastness with respect to washing, rubbing and exposure to light, the jackfruit bark dye can be applied on silk with any of the selected mordants at 3% level.

Colour Change Caused by Dry Cleaning Process on Painted Surfaces

Over the last few years, the dry cleaning process has become an excellent alternative to solvent or water-based mixtures, which prevents diffusing the dirt into the painting structure during the cleaning process. The use of this kind of cleaning is especially effective on contemporary paintings as it prevents the solubilisation of additives such as the surfactants contained in polymeric dispersions (e.g. in acrylic and PVAc-based paints). In addition to some reported side effects that could be caused by dry cleaning processes on paintings (such as changes in the integrity of the paint or any residual materials which may be left behind) one parameter that should be tested is the colorimetric change seen on treated surfaces. In some cases, the use of certain dry cleaning materials can cause burnishing or roughening of the painted surface. This effect results in a change in brightness and chroma and subsequently to a change in the colour of the treated area, especially on dark shades. This article evaluates the colorimetric change of different kinds of painted surfaces caused by the dry cleaning process, such as gouache, commercial formulated acrylic, fish glue tempera, casein tempera, PVAc and primal acrylic paint. The cleaning materials tested include different kinds of sponge cloths, malleable materials and erasers used in the field of heritage conservation/restoration. The change in colour is measured by means of a spectrophotometer and the chromatic values are processed in a spreadsheet. The colorimetric changes have been calculated using the advanced equation recommended by CIEDE2000 and the chromatic values obtained have been studied following the standard recommendations.

Assessing the colour changes of woven polyester automotive seat cover fabrics under ultraviolet light

This paper assesses the changes in colour differences (ΔE*ab), lightness (L*), chroma (C*) and colour strength (K/S) values of polyester automotive seat cover fabrics after five durations of exposure to ultraviolet (UV) light using different fabric constructional parameters. At each level, the UV-exposed fabric was compared with the fabric in its original state and the colour properties were determined. The ΔE*ab colour difference values of all of the fabrics increased as the fabric cover factors decreased. The chroma and colour strength values decreased and the lightness values increased as the exposure times increased. Compact fabric structures with high cover factor values that were woven from high-count yarns with a high number of yarn crossings were found to be more resistant to UV exposure. To produce fabrics that are colourfast in UV light, the constructional parameters of the fabrics must be carefully chosen in terms of yarn and fabric constructional properties.

Vector‐based modelling of colour difference: a pilot study of the DE 2000 colour difference model

A novel approach to colour difference modelling is presented whereby for any given CMC (1:1) or CIE DE2000 ∆E, ∆C, ∆H, and ∆L colour difference, the equivalent CIE XYZ, L*a*b*, and L*C*h coordinate changes are derived by optimising the input RGB stimuli from which they are all calculated. Single-dimension L or C or H difference loci expressed in DE2000 difference units are thus generated, and the additive equivalence of tristimulus values is likewise projected forward onto each locus and also onto a set of CIE DE2000 three-unit ellipse boundaries. Using the datasets thus generated, it is then shown firstly that the derived ellipses have well-defined semi-axes, which explain the detailed orientation of the MacAdam ellipses in x,y,Y space. Unit CIE DE2000 difference is confirmed as a successful quantifying constant of visual difference over a wide range of chroma, hue, and lightness differences. As a constant, CIE DE2000 unit difference is shown to have a significantly variable value at high and low chroma: evidence is established for systematic changes in both chroma and hue difference sensitivity. A hitherto unresolved non-linearity is revealed in the C* dimension of L*C*h space that is not replicated in the CIE DE2000 model. The derived difference loci appear to specify physically reproducible experimental stimuli that could be used in the estimation of visual difference magnitude. Overall, the data derived by the new approach and presented in this paper increase the probability that a true vector model of the visual difference response may eventually be derived.

Spectral and Color Changes of Ag/TiO2 Photochromic Films Deposited on Diffusing Paper and Transparent Flexible Plastic Substrates

Giving paper and polymer photochromic properties under laser irradiation is challenging due to the low resistance of these materials to heat, their flexibility, and their possibly irregular structure. However, we could successfully deposit TiO2/Ag/TiO2 layers stacking on flexible white glossy paper and transparent polyethylene terephalate (PET) substrates using a reactive magnetron sputtering technique, and tailor coloration changes after laser irradiation, alternating visible and ultraviolet (UV) wavelengths. The sample colors are characterized by a panel of chromas depending on the irradiation conditions. We demonstrate that these chroma changes are due to morphological changes of Ag nanoparticles (NPs) after visible laser irradiation of the colored as-deposited sample. The process exhibits a good reversibility after subsequent UV irradiation due to the growth of new metallic Ag NPs. The colors displayed in diffuse reflection by the paper samples are more saturated than the ones displayed in regular transmission by PET samples. We demonstrate the efficiency of the photochromic process on such support by printing high resolution patterns exhibiting different colors depending on the observation conditions.

The colors of paintings and viewers’ preferences

One hypothesis to explain the aesthetics of paintings is that it depends on the extent to which they mimic natural image statistics. In fact, paintings and natural scenes share several statistical image regularities but the colors of paintings seem generally more biased towards red than natural scenes. Is the particular option for colors in each painting, even if less naturalistic, critical for perceived beauty? Here we show that it is. In the experiments, 50 naïve observers, unfamiliar with the 10 paintings tested, could rotate the color gamut of the paintings and select the one producing the best subjective impression. The distributions of angles obtained are described by normal distributions with maxima deviating, on average, only 7 degrees from the original gamut orientation and full width at half maximum just above the threshold to perceive a chromatic change in the paintings. Crucially, for data pooled across observers and abstract paintings the maximum of the distribution was at zero degrees, i.e., the same as the original. This demonstrates that artists know what chromatic compositions match viewers’ preferences and that the option for less naturalistic colors does not constrain the aesthetic value of paintings.

Effect of different drying techniques on physical properties, total polyphenols and antioxidant capacity of blackcurrant pomace powders

The effect of freeze-drying (FD), convective (50 °C–90 °C; CD), microwave vacuum (120W, 240W, 360W, 480W; MVD) and combined (CD-MVD) drying on the physico-chemical properties of blackcurrant pomace powders was examined. A relationship was analysed between moisture content, water activity, solubility, true and bulk density, porosity, colour, total polyphenolic compounds, and antioxidant capacity and drying parameters. The lowest water activity was noted after CD suggesting that CD is more effective in water removal from pomace than MVD or CD-MVD. CD decreased solubility of powders to significantly greater degree than MVD and CD-MVD. Drying processes improved the colour of the blackcurrant pomace powders in comparison to the raw material. Power function between the temperature of the process and the changes in chroma was established, whereas a rational function was found during MVD. Functional relation between the temperature and total polyphenolic content and antioxidant capacity was found.