Color Stability Research Articles

Preparation and evaluation of gelatin-based films with colorimetric/fluorescent response, enhanced hydrophobicity and stability for smart fish packaging

Smart packages based on natural pigment and macromolecular exhibited great potential in fresh meat but were limited by their poor stability and hydrophobic properties. Herein, we designed a stable smart packaging consisting of a series of preservation films (GPEF series) and smart labels (GPEF-C series), through emulsification and polyelectrolyte complexation. Cinnamic acid-chitosan nanoparticles (CC NPs) were used to prepare gallic acid-garlic essential oil W/O/W emulsions (EC) and emulsions loaded with curcumin (EC-Cur). The added emulsions and in-situ generated calcium CaHPO4 nanoparticles significantly improved the hydrophobicity of films (WCA 111.3°–124.8°). As the emulsion concentration increased, films exhibited significant enhancement in antioxidant activity (50.2%–97.6%), antimicrobial properties (12.4%–99.8% against E. coli, 89.9%–100% against S. aureus) and UV shielding properties (transmittance 0.7%–5.1%). Moreover, these films were environmentally friendly and degraded in soil after 10 days. GPEF-C3 and GPEF-C5 showed excellent color and fluorescence stability after 4.5 months, as well as pH response between pH 8–13. Compared with PE, GPE5F extended the shelf life of fish at 4 °C from 3 days to 5 days, and the color/fluorescence response of GPEF-C3 exhibited consistency with TVB-N and CFU, which could accurately reflect the freshness of fish in real-time. Smart packaging based on GPE3F and GPEF-C3 was a prospective option for preserving and monitoring fresh meat.

Flexural strength, surface roughness, and color stability of various CAD-CAM denture teeth materials.

To assess the flexural strength (FS), surface roughness, and color stability of additive manufactured (AM) and subtractive manufactured (SM) denture teeth materials, as well as the effect of thermocycling on these properties. Eighty strips (20/material type; 64×10×3.3mm) and 60 discs (15/material type; 12×4mm) were fabricated from four different denture teeth materials (Straumann, Flexcera, Ivoclar, and Candulor). The specimens were divided into two subgroups (nonthermal cycled and 5000 thermal cycled,10 per subgroup), and subjected to a 3-point test for FS using a universal testing machine at a crosshead speed of 5.0mm/min. Surface roughness (Ra, µm) and color differences (ΔE00) of disc specimens were measured before and after thermocycling using a noncontact optical profilometer and a spectrophotometer, respectively. The CIEDE2000 formula was used to calculate the color differences (ΔE00) before and after thermocycling. Data were analyzed using 2-way ANOVA followed by post hoc multiple comparison tests (α=0.05). There was no significant difference in flexural strength between nonthermal cycled SM materials (p=0.15), which were significantly higher than AM materials (p<0.001). The flexural strength values of all tested materials weresignificantly reduced after thermocycling (p<0.05). The material type had a significant effect on the Ra values (p<0.001), whereas thermocycling did not (p=0.81). After thermocycling, all materials exhibited color changes lower than the clinical perceptible threshold (ΔE00=2.7). Thermocycling decreased the FS of denture teeth materials manufactured with AM and SM, but did not affect the surface roughness. The FS values of SM groups were significantly higher than AM materials, irrespective of thermocycling. No clinically significant color changes of the denture teeth material were noted.

Color Stability of Microhybrid Composite Resins Depending on the Immersion Medium.

The aim of this study was to assess the color stability of two microhybrid composite resins after immersion in different coloring solutions for 4 weeks. Sixty disc-shaped samples (2 mm in thickness and 10 mm in diameter) were prepared according to ISO standard 4049. Two composite resins were used: Filtek Z350 XT (3M ESPE) and Harvard Restore (Harvard Dental International GmbH). After initial color measurements, five samples of each resin were immersed in artificial saliva, Turkish coffee, lemonade, black tea, Coca-Cola 0%, and green tea for 4 weeks. The spectrophotometric measurements were carried out after 24 hours of immersion in the various solutions and then weekly, using a VITA Easyshade Advance 4.0 spectrophotometer (CIE L*a*b* system). Statistical analysis was carried out with SPSS 25.0 software. The two composite resins tested revealed discoloration after immersion in all the drinks at a variable immersion period showing different color behaviors. The one-way analysis of variance showed a significant difference in the values of brightness (L), in chromaticity from green to red (a), in chromaticity from blue to yellow (b), and in the color (ΔE) of the two materials at different time intervals. The greatest color change in all the groups was caused by coffee followed by lemonade and black tea followed by green tea, Coca-Cola 0%, and artificial saliva. The importance of color stability of dental restorations is crucial for dental professionals and patients. Indeed, the quality of a restoration is considered from both a functional and esthetic points of view. The information obtained from this study should prove useful for clinicians to make informed decisions in selecting the best materials for their patients' esthetic restorations. The Harvard Restore showed a better colorimetric behavior compared with the Filtek Z350. Coffee, black tea, and green tea had the most marked effects on the discoloration of composites, especially on Filtek Z350. Coca-Cola 0% showed a similar behavior to artificial saliva.

Conditions for thermally stable color characteristics of trichromatic white light-emitting diodes

We present a method to stabilize color characteristics from a trichromatic white light-emitting diode (LED) consisting of red, green, and blue (RGB) LEDs under varying ambient temperatures. Through colorimetric analyses, it was found that the trichromatic white LED could maintain its chromaticity coordinate by adjusting the light output power (LOP) of green and red LEDs as the temperature varied. Moreover, the correlated color temperature (CCT) could be invariant to the external temperature change by controlling only the LOP of a red LED. Using the developed mathematical model and temperature-dependent spectral data of commercial RGB LED samples, we determined the power ratios between RGB LEDs needed to achieve thermally stable color coordinates or CCT as the heat sink temperature varied from 20 to 100 °C. When operating under thermally stable CCT conditions, the chromaticity coordinate of the trichromatic LED moved along the iso-CCT line with only a minor color deviation as the temperature increased to 100 °C. The presented approach requires adjusting the power of only one LED to achieve thermally stable CCT operation in a trichromatic white LED, which is expected to simplify LED control circuits significantly.

New Insights into pH-dependent Complex Formation between Lignosulfonates and Anthocyanins: Impact on Color and Oxidative Stability.

Anthocyanins have limited application as natural colorants and antioxidants due to their color loss and instability under certain conditions. This research explores the formation of a complex between lignosulfonates (LS) and cyanidin-3-O-glucoside (C3G) using a multitechnique approach as well as the effect on C3G's red color, oxidative stability, and antioxidant activity in acidic mediums. All data revealed pH-dependent LS-C3G interactions. The thermodynamic parameters showed weak noncovalent interactions, mainly electrostatic interactions, hydrogen bonds, and hydrophobic effect, with a higher association constant determined at pH 3. Fourier-transform infrared spectroscopy and Zeta-potential experiments further corroborate evidence of these LS-C3G interactions. Fluorescence quenching and lifetime experiments revealed static and dynamic quenching at pH 1 and 3, respectively. UV-visible spectroscopy demonstrated a bathochromic shift upon complex formation and a hyperchromic effect at pH 3 and 4, as a consequence of the improved red color of C3G. Electrochemical results suggested that at pH 3 the LS enhances C3G stability by protecting its oxidizable moieties over time, as well as improving the antioxidant activity of the anthocyanin in the complex.

Low current driven blue-violet light-emitting diodes based on p-GaN/i-Ga2O3/n-Ga2O3:Si structure

This paper reports a low current driven LED with p-GaN/i-Ga2O3/n-Ga2O3:Si structure prepared by radio frequency (RF) magnetron sputtering, the driving current of the device is only 0.02 mA. Compared with the reported drive current of the LEDs, the reduction is 100 or even 1000 times. Through the study of its electrical properties, it was found that it had excellent rectification characteristics at different ambient temperatures and the turn-on voltage was about 1.8 V. In addition, the leakage current was as low as 4.30 × 10-8 mA. Through the electroluminescence test, it was found that the device had the function of emitting in the ultraviolet (363 nm) and visible (425 nm) region, which realized the blue-violet luminescence at room temperature. Furthermore, the device had excellent high temperature color stability and ultra-low color temperature of 1924 K. The color coordinate of the device at room temperature was (0.1905,0.0955). A detailed study was conducted on the electroluminescence mechanism of the device through its band structure, and the causes of the luminescence were analyzed through the Gaussian fitting of the EL spectrum.

Reactive carbon dots/polysiloxane composites cross-linked silicone resin adhesives for stable white LED constructing

Current high-performance commercial white LEDs typically rely on Ce:Y3Al5O12 (Ce:YAG) phosphors and their dispersed encapsulating material. However, Ce:YAG often has large particle sizes and does not react with the encapsulating material, causing stratification and sedimentation. To address this problem, a novel reactive carbon dots/polysiloxane (R-CDs/PS) composite was synthesized through a one-step solvothermal process involving citric acid, urea, 3-aminopropyltriethoxysilane (APTES), and vinyltrimethoxysilane (VTMS). The composite exhibits yellow emission at 528 nm under UV excitation and has a particle size of approximately 150 nm. To improve integration, vinyl adhesive (vinyl AD) and vinyl MDQ resin were designed and synthesized to enhance adhesion and mechanical strength. When dispersed in silicone resin adhesives (SRAs), R-CDs/PS composite forms a stable color conversion layer, avoiding stratification due to its nanoscale size and chemical cross-linking with SRAs. White LEDs can be easily produced by casting R-CDs/PS composites and SRAs onto LED chips, followed by high-temperature curing. These LEDs exhibit desirable optical properties, including CIE coordinates of (0.33, 0.34), a CRI of 82.2, and a CCT of 5355 K, making them suitable for indoor lighting. This study not only introduces a practical approach for fabricating fluorescent and encapsulating materials but also offers a valuable strategy for improving the stability of white LEDs.

Effects of Mouthwashes and Surface Treatments on the Color Stability and Surface Roughness of a Three-Dimensional Printed Interim Crown Material

Background: To evaluate the color stability and surface roughness of a 3D-printed interim crown material subjected to different surface treatments while immersed in various mouthwashes. Methods: The specimens (n=56) were manufactured with a digital light processing 3D printer. Half of the specimens were coated with one layer of Ultra Glaze varnish, and other half were polished with OptraGloss. After the initial color and surface roughness values were measured, specimens were immersed in different solutions [3 mouthwashes (Andorex, Tantum Verde and Listerine) and distilled water] for 24 hours. After solution exposures, color and surface roughness measurements were repeated, and the color change (ΔE) was calculated. Two-way ANOVA and Tukey’s test were performed to analyze the color difference and surface roughness of the specimens (p&lt; .05). Results: Listerine caused lower discoloration compared with other mouthwashes in both polish (4.11±1.0) and glaze (3.71±0.98) groups (p&lt; .05). ∆E was greater than the perceptibility (1.3) and acceptability thresholds (2.25) for both polish and glaze groups immersed in mouthwashes. Before solution immersion, the polish group (0.421±0.122) had greater surface roughness values than did glaze group (0.073±0.024) (p&lt; .001). The surface roughness of the mouthwashes and distilled water were similar for both polish and glaze groups (p&gt; .05). After solution immersion, all groups showed greater surface roughness, except for the polish group, which was immersed in Tantum Verde (p&lt; .05). Conclusion: Mouthwashes negatively impacted the surface roughness and color stability of 3D-printed resin. The use of glazes for 3D-printed interim crowns can be recommended for long-term use. Keywords: Mouthwashes, Surface Properties, Temporary Dental Restoration, Tooth Discoloration

Development of pH-Sensitive intelligent films incorporating betacyanin from dragon fruit peel and TiO2 nanoparticles for monitoring fish fillet freshness

This study aimed to develop novel pH-sensitive intelligent films for monitoring food freshness by incorporating betacyanin extracted from dragon fruit peel, pectin, sodium alginate, and titanium dioxide (TiO2) nanoparticles. Pectin and betacyanin were simultaneously extracted from dragon fruit peel and combined with sodium alginate and TiO2 nanoparticles to create composite and double-layer films. The films were comprehensively characterized to evaluate their physical, mechanical, structural, and functional properties. Additionally, their effectiveness in monitoring the freshness of mackerel fillets was assessed. The incorporation of TiO2 nanoparticles significantly enhanced film properties, with tensile strength increasing from 3.55-13.42 MPa to 13.85–14.90 MPa, water vapor permeability decreasing from 1.58 to 3.00 × 10−9 g/msPa to 1.54–3.00 × 10−9 g/msPa, and swelling degree reducing from 294-330% to 260–261%. TiO2 nanoparticles effectively immobilized and protected betacyanin from photodegradation, crucial for maintaining color stability. The subjected films demonstrated color changes from reddish-violet to brownish-yellow, correlating with increasing TVB-N levels in mackerel fillets. The double-layer film exhibited superior stability under both dark and light conditions compared to the composite film. This study uniquely combines dragon fruit peel-derived pectin and betacyanin with TiO2 nanoparticles, addressing the growing demand for eco-friendly packaging solutions by utilizing food waste and developing biodegradable alternatives to synthetic pH indicators.

Effect of sintering temperature on color stability and translucency of various zirconia systems after immersion in coffee solution.

Achieving the aesthetic standards in tooth-colored restorative materials requires close attention to their color, translucency, and resistance to discoloration. This study aimed to evaluate the effect of sintering temperature on color stability and translucency in zirconia systems with low, high, and ultra-high translucencies. This experimental study was conducted on 60 zirconia disks with low, high and ultra-high translucencies (n = 20 per group), each group divided into subgroups to be sintered at either 1450°C or 1550°C (n = 10 per subgroup). Baseline color and translucency parameters were measured, the specimens were then immersed in coffee solution for 30 days, and the measurements were repeated post-immersion. Changes in color (ΔE) and translucency (ΔTP) were calculated via CIELAB formula and compared by using two-way ANOVA and Tukey's post hoc test (α = 0.05). Results of two-way ANOVA showed that the ΔE was significantly different among the three zirconia translucencies (P<0.001), but no significant difference was found between the two sintering temperatures (P = 0.712). Additionally, the interaction between zirconia type and sintering temperature was not statistically significant for ΔE (P = 0.264). The low-translucency group showed significantly greater ΔE than the high-translucency and ultra-high-translucency groups (P<0.05), while the high- and ultra-high-translucency groups were not significantly different in this regard (P>0.05). Regarding the ΔTP, two-way ANOVA showed that the difference was not statistically significant either among the three zirconia types (P = 0.4430) or between the two sintering temperatures (P = 0.4544). Nor was the interaction between zirconia type and sintering temperature statistically significant (P = 0.5505). It was concluded that sintering temperature had no effect on color and translucency changes after immersion in coffee. Whereas zirconia type significantly affected the color changes after immersion in coffee; with the higher-translucency zirconia types being significantly more color-stable than the low-translucency zirconia.

Evaluation of Colour Stability of Activa Pronto and Beautifil Flow Plus in Three Different Solutions - An In Vitro Study

Objective: To assess the colour stability of two bioactive restorative materials Activa Pronto (Pulpdent, USA) and Beautifil Flow Plus (Shofu, Japan) when exposed to three commonly consumed beverages: coffee, tea, and Coca-Cola.Materials and Methods: 80 disc-shaped specimens were prepared, 40 samples each of the material and were divided into four groups based on the staining solution, which included: distilled water (control), coffee, tea, and Coca-Cola. The specimens were placed in the respective solution for 30 days. Solutions were replaced daily to avoid contamination. Color measurements were performed before (baseline) and after 30 days using a VITA Easyshade spectrophotometer, and the colour changes (ΔE) were calculated in the CIE Lab* system.Results: For the ΔE values, Activa Pronto showed significantly lower values than Beautifil Flow Plus in both coffee (p=0.001) and Coca-Cola (p=0.000) solutions. In the tea group, no significant difference was observed (p=0.223). Activa Pronto generally had more stable color, especially in acidic and staining solutions like coffee and Coca-Cola solutions.Conclusion: Activa Pronto presented greater color stability than Beautifil Flow Plus; therefore, it is a more suitable material for patients who would take much notice of the aesthetic appearances of their restorations in the long term. The most stained materials by Coca-Cola and coffee meant further investigation into the long-term clinical behaviour of these materials was essential.

Effect of Various Carbohydrates in Aqueous Solutions on Color Stability and Degradation Kinetics of Selected Anthocyanins During Storage.

Anthocyanins are flavonoid substances of plant origin with potential antioxidant effects. Because of their intense colors, they are used as natural dyes in food. However, their stability in food matrices is limited. This study aimed to verify the effect of selected carbohydrates on the stability of anthocyanins (cyanidin-3-O-β-glucopyranoside, cyanidin-3-O-β-galactopyranoside, cyanidin-3-O-β-rutinoside and delphinidin-3-O-β-rutinoside) during the accelerated storage test, since carbohydrates help to preserve the typical color of anthocyanins, increase their shelf-life and availability in the organism, and reduce losses during processing. Moreover, the kinetic parameters of anthocyanin degradation (Ea, k, t1/2) were determined. Sucrose was found to have the greatest potential for retarding anthocyanin degradation during storage, whereas fructose exerted an accelerating effect. Glycosidation of anthocyanin aglycone had no significant effect in terms of their stability. Anthocyanin degradation was significantly positively correlated with the change in the a* parameter (redness), and subsequently, a significant positive correlation was observed in the determination of the kinetic parameters for anthocyanins and the a* parameter. The highest stability of anthocyanins was observed in the presence of sucrose and their degradation can be predicted by the value of the a* parameter, which would also be a very fast and non-destructive method for food processing companies.

Development and Quality Enhancement of Fried Fish Cake Prototype with Transglutaminase, Trehalose, and Herbal Oil for Room Temperature Distribution.

This study focuses on developing a fried fish cake prototype with improved quality and extended shelf-life, enabling room-temperature distribution through an innovative high-temperature and high-process retort method. Surimi-based products typically necessitate cold storage and a refrigerated distribution system, affecting their physical properties and flavor while escalating costs. By incorporating Transglutaminase (TGase), trehalose, and herbal oils, and optimizing the heating process using the response surface methodology, this research addresses challenges related to changes in physical properties, color, and off-flavors during high-temperature and high-pressure treatment. The addition of 0.37% ACTIVA-K TGase significantly enhanced gel strength by promoting protein cross-linking, while 0.75% trehalose improved color stability by suppressing browning, thus enhancing visual appeal. A 0.1% concentration of bay oil effectively enhanced the flavor profile by masking undesirable odors without compromising the sensory quality. Optimized processing conditions maximized DPPH radical scavenging activity, whiteness, and gel strength, ensuring superior product quality and safety. Nutritional analysis confirmed a balanced composition of moisture, protein, essential amino acids, and minerals, in accordance with Korean national standards for acid values. Microstructural examination revealed a uniform network structure, contributing to excellent texture and sensory evaluations. Shelf-life predictions indicated a storage duration of approximately 19 months, surpassing commercially available products and offering a competitive edge. This novel approach allows surimi-based products to be stored and distributed at room temperature, while also providing the potential for increased profitability.

Evaluation of Colour Stability in Orthodontic E-Chains in Various Solutions: An in Vitro Study

This in vitro study aimed to evaluate the colour stability of orthodontic elastomeric chains (E-chains) immersed in various solutions, simulating conditions encountered during orthodontic treatment. A total of 75 samples were divided into 5 groups based on the solutions used for immersion: control medium, chlorhexidine mouthwash, carbonated drink, honey lemon water and turmeric water in the time duration of 12hrs, 24hrs and 72hrs such as 5 samples per solution and time. The colour stability was assessed using the CIE Lab* colour space system, and changes were quantified using the ΔE* (Delta E) formula. The results demonstrated significant differences in colour stability across the solutions. In descending order, the colour of the samples was: turmeric water, honey lemon water, carbonated drink, chlorhexidine mouthwash and control medium. The findings indicated that exposure to chromogenic solutions can adversely affect the aesthetic properties of E-chains, which may influence patient satisfaction and treatment outcomes. The study highlights the importance of understanding the impact of dietary habits on the aesthetic integrity of orthodontic E-chains. Further research is warranted to explore the long-term implications of these findings on orthodontic treatments and to investigate potential methods to enhance the colour stability of E-chains in clinical settings.

Comparative Analysis of Modern 3D-Printed Hybrid Resin-Ceramic Materials for Indirect Restorations: An In Vitro Study.

The study investigated the impact of aging on surface roughness, color stability, and biocompatibility of hybrid resin-ceramic materials. A total of 225 specimens were produced from three three-dimensional (3D)-printed (HarzLabs Dental Sand Pro (HL), BEGO VarseoSmile Crown plus (BV), Voco V-Print c&b temp (VV)) and one milled material (Voco Grandio Blocs (VG)). Specimens were grouped into untreated, polished, and glazed surfaces. 5000 thermal cycles simulated aging. Surface roughness and color stability were analyzed, and surface topography was observed using scanning electron microscopy (SEM). Biocompatibility was evaluated with L929 cells. Surface roughness differed significantly between untreated and other groups, with no changes before and after artificial aging. Untreated milled samples were significantly smoother than 3D-printed ones. SEM analysis revealed roughest surfaces in untreated 3D-printed specimens. Polished and glazed specimens were smoother than untreated ones. Color values showed significant differences between untreated and treated/aged groups. No material showed cytotoxicity. In summary, untreated VG was smoother than 3D-printed materials, but polishing and glazing reduced roughness to levels comparable to VG. Surface treatments induced color changes, with glazing causing more changes than polishing. Aging affected color stability and biocompatibility but not surface roughness. All materials showed acceptable color changes and good biocompatibility.

Effect of Repeated Firings on Color Stability of Zirconia- Reinforced Lithium Silicate and Lithium Disilicate Ceramics.

The purpose of this invitro study was to assess the changes in the color attributes of high-translucency (HT) lithium disilicate and zirconia-reinforced lithium silicate in BL3/0M1, A1, A2, and A3 shades during first, second, and third firing cycles. Eighty specimens of two ceramic systems (IPS e.max CAD and Vita Suprinity) in BL3/0M1, A1, A2, and A3 shades, were prepared in thickness of 1 mm (n=10). Each group was subjected to 3 firing cycles and the CIE L*a*b* color parameters of specimens were measured after each firing cycle by a reflectance spectrophotometer. The color change (ΔE) between each two firing cycles was calculated by the relevant equation. Data were analyzed by one-way ANOVA and Tamhane post hoc test. All ΔE values were significant (P⟨0.001) except for ΔE2-1 (color difference between second and first firing) and ΔE3-2 (color difference between third and second firing) in A2 shade of IPS e.max (P=0.436) and ΔE2-1 and ΔE3-2 in 0M1 shade of Suprinity (P=0.345). Repeated firing resulted in generally higher ΔE in ZLS than LDS, and 0M1 Suprinity experienced maximum ΔE after repeating firing.

Spectrophotometric Evaluation of the Color Stability of Nanofilled Composites With and Without a Dentin Bonding Agent as a Surface Sealer Following Exposure to Common Beverages

Spectrophotometric Evaluation of the Color Stability of Nanofilled Composites With and Without a Dentin Bonding Agent as a Surface Sealer Following Exposure to Common Beverages

Performance evaluation of pigmented fair-faced concrete under various environments: Mechanical properties, apparent properties, and color stability

Fair-faced concrete is green concrete that is directly decorated by its texture. For a more stunning visual impact, pigmented fair-faced concrete with more colors on the surface is prepared. However, the effects of different pigments and service environments on pigmented fair-faced concrete need to be explored. Therefore, four iron oxide inorganic pigments were employed to prepare pigmented fair-faced concrete, and the changes in its fresh properties and mechanical properties were studied through slump, slump flow, and compressive strength tests. Meanwhile, camera analysis and colorimetry were utilized to evaluate the changes in its apparent properties and color stability under four different distinct service environments in this experiment. Results indicate that incorporating pigments reduces both the slump and slump flow of the fresh mixture, and its fresh properties gradually decrease as the pigment content increases. The slump and slump flow of concrete with 6 % iron oxide yellow (IOY) were 30.00 % and 44.00 % lower than the control. Adding IOY and iron oxide red (IOR) can improve the 7-d and 28-d compressive strength of concretes. The 28-d compressive strength of concrete with 2 %-6 % IOY increased by 7.72 %, 11.78 % and 15.09 % over the control. Meanwhile, the surface pore area of concrete with IOY is the lowest and that of concrete containing 2 % IOY is 3.97 cm2/m2. Additionally, the color stability of concrete performs best in water immersion environments and worst in natural environments. It is noteworthy that the concrete added with IOY exhibits excellent color stability under all four service environments. This study aims to evaluate the effects of different pigments on concrete properties and investigate the color stability of four types of concrete under diverse service conditions. The findings will promote the application of pigmented fair-faced concrete in construction and provide technical insights for future research.

Microencapsulation of Caucasian blueberries (Vaccinium arctostaphylos L.) anthocyanins: Colour stability in varying storage conditions

AbstractThe aim of this study was to investigate the extraction of anthocyanins from the fruits of Caucasian blueberry (Vaccinium arctostaphylos L.) and examine the colour stability of anthocyanins encapsulated through spray drying in model systems. The trials were conducted to determine the optimal conditions for anthocyanin extraction using an ultrasonic water bath at temperatures of 25, 50 and 75°C. The ideal anthocyanin extraction occurred at 25°C using 100% acetone in an ultrasonic bath for 15 min at 35 kHz. Anthocyanin concentrations were evaluated using the pH differential method. The extracted anthocyanins were encapsulated through spray drying with maltodextrin as the encapsulating material. The encapsulation efficiency was 80.4 ± 0.20%, and the anthocyanin retention rate was 83.0 ± 0.76%. The coloured capsules were added to model systems with pH values of 4.50, 5.00, 5.50 and 6.00. The colour values (L* 50.16 ± 0.05, a* 4.08 ± 0.04, b* −9.35 ± 0.01, H° 293.57 ± 0.15, C* 10.20 ± 0.03) were measured during varying storage conditions. The results showed, that colour loss began on the fifth day and this was accelerated with higher temperatures and pH values. It was found that encapsulation significantly preserved the stability of the blue colour and the loss of the blue colour followed first‐order reaction kinetics. The study showed that the blue colour of microcapsules was best preserved at pH 5.00 at 25°C. In this case, the measured total colour change (∆E) was 5.86, the activation energy (Ea) was 37.64 kJ/mol, and the half‐life (t1/2) was determined to be 19.08 days.

Betalains as Natural Dyes and Applications

Betalains are natural pigments that include betacyanin and betaxanthin, found in plants such as beets and cacti. In the food industry, betalains are used as natural colorants due to their color stability and health benefits, including antioxidant and anti-inflammatory properties that support the prevention of degenerative diseases. With increasing demand for natural ingredients, betalains are also being promoted in the cosmetics and health product industries. In the healthy food sector, new extraction techniques like microwave-assisted extraction and aqueous two-phase technology have improved the purification efficiency and quality of betalain pigments. In cosmetics, betalains are utilized as anti-aging and anti-inflammatory components, with innovative approaches like biopolymer encapsulation to enhance product stability. Geographical trends show significant interest in betalain use in natural cosmetics and healthy foods in Europe and Asia, while research in Latin America focuses on its potential as a supplement and food colorant. In renewable energy technology, betalains act as photosensitizers in dye-sensitized solar cells (DSSCs), though their stability still requires optimization, such as through co-sensitization with other pigments. These innovations suggest that betalains hold considerable potential in the food, cosmetics, and energy industries, making them a versatile and globally relevant natural material.