Changes In Color Parameters Research Articles

Kinetic Modeling of Quality Changes and Shelf Life Prediction of Dried Coconut Chips

The color, texture and rancidity of dried fruit are critical parameters to control for consumer acceptance. The goal of this research was to investigate the kinetics of color parameter changes and texture in terms of the crispness and peroxide value (PV) of dried coconut chips by using zero-, first- and second-order kinetic reactions during storage at different temperatures, as well as shelf life prediction using the accelerated method. The outcomes demonstrated that the zero-order kinetic reaction was appropriate to describe the change in color, crispness and PV of dried coconut chips during storage (R2 = 0.9690–0.9899). The rancidity had a higher correlation than the texture and color changes used to assign the quality essence. The activation energy (Ea) for the PV change was 11.83 kJ/mol. Therefore, the shelf life expectancy of the dried coconut chips was estimated to be 144, 128 and 115 days at 35, 45 and 55 °C, respectively. Meanwhile, the shelf life of products stored at ambient temperature was 159 days, and those products were stored in the refrigerator for 194 days. The findings provide retailers and consumers the ability to choose the ideal temperature and storage time for dried coconut chips in order to ensure the product’s quality.

Color alteration with ceramic veneers according to the tooth type and preparation step: A clinical analysis

Statement of problemAchieving accurate tooth color is important in esthetic dental treatments; however, clinical studies evaluating how ceramic veneer procedures affect color alterations are lacking. PurposeThe purpose of this clinical study was to assess the color alteration during treatment with ceramic veneers and to correlate these changes with the tooth treated and veneer thickness. Material and methodsTen patients who underwent esthetic treatment were enrolled as participants. Color analysis with the VITA spectrophotometer was performed at baseline, after tooth preparation, immediately after cementation (Final 1), and after 6 to 12 months of follow-up (Final 2). Data of L∗, a∗, b∗, shade guide unit (SGU), ΔEab, ΔE00, and variation in SGU (ΔSGU) were obtained. Thickness of the veneer was also recorded. Each participant was considered as a statistical block, and the mean results for each tooth (maxillary central incisors, lateral incisors, and canines) were presented. Data were evaluated by the mixed model for repeated measures and Tukey-Kramer post hoc test (L∗, a∗, b∗), generalized linear models (thickness, ΔEab, ΔE00, SGU), Friedman test (ΔSGU), and the Pearson test was used to correlate veneer thickness and color change (ΔEab, ΔE00, ΔSGU) (α=.05). ResultsAmong the teeth treated, no differences were found in ceramic thicknesses. The mean thickness was 1.03 mm for central incisors, 0.96 for lateral incisors, and 0.89 for canines. The b∗ values increased significantly after preparation and decreased after cementation (P<.001). For ΔEab, ΔE00, and ΔSGU, there was no statistically significant difference between the types of tooth at each respective time of analysis (P>.05). Regardless of the tooth, a decrease in the SGU score was detected after cementation (P=.015). After tooth preparation, there was significant correlation (P<.05) between ceramic thickness and ΔSGU (r=0.36). ConclusionsTreatment with ceramic veneers resulted in color change, mainly with respect to the b∗ axis (yellow), producing objective differences in the ΔE analysis. Although ceramic thickness correlated with the VITA scale change (ΔSGU) after tooth wear or preparation, ceramic thickness did not differ among tooth types and did not correlate with changes in color parameters after cementation. (P>.05).

Effects of Sodium Alginate Edible Coating with Cinnamon Essential Oil Nanocapsules and Nisin on Quality and Shelf Life of Beef Slices during Refrigeration

The effects of a new edible sodium alginate (SA) coating incorporating cinnamon essential oil nanocapsules (CEO-NPs) and nisin were investigated with beef slices in refrigerated storage for 15 days. All beef samples were analyzed for physicochemical properties (pH, weight loss, and total volatile base nitrogen) and antimicrobial activity against total bacteria. Changes in color parameters and sensory attributes of all beef samples also were evaluated. Incorporation of the complex of CEO-NPs and nisin into the SA coating retarded the growth of microorganisms and reduced lipid oxidation, as determined by pH, total volatile base nitrogen, and total bacteria counts. This treatment also extended the shelf life of beef slices to 15 days. The SA coating with CEO-NPs and nisin significantly reduced weight loss and improved color, odor, texture, and purge quality of the beef samples. These results suggest that treatment with the SA coating enriched with CEO-NPs and nisin can significantly retard the deterioration of beef slices, and the complex of CEO-NPs and nisin can improve antioxidant, antibacterial, and sensory properties of the SA coating. This new edible coating could be useful for preserving beef slices.

Impact of the Filling Medium on the Colour and Sensory Characteristics of Canned European Eels (Anguilla anguilla L.).

The different vegetable oils used in canned fish as a filling medium have a preserving effect and contribute to the palatability of the product. In this study, the colour of European eels and the filling medium (sunflower oil, olive oil or spicy olive oil) was measured at different steps of the canning process. The sensorial characteristics of canned eels packed in the different oils were also evaluated. Colour scores (CieLab values) were higher in canned eels packed in sunflower and spicy olive oil than in canned eels packed in olive oil. The changes in colour parameters depended on the type of oil, the stage of the process and the storage time. Colour changes in canned eels packed in olive oil were highest during the sterilization process. Spicy olive oil was the filling medium in which the colour change was greatest, probably due to the migration of some of the spice components into the oil. Organoleptic properties were directly related to the type of oil used as the filling medium. The canned eels packed in sunflower oil were those awarded the highest scores in consumer tests, although the preferences varied depending on the age and gender of the consumers.

ABA Speeds Up the Progress of Color in Developing F. chiloensis Fruit through the Activation of PAL, CHS and ANS, Key Genes of the Phenylpropanoid/Flavonoid and Anthocyanin Pathways.

Phenolic compounds with antioxidant properties have risen in interest due to their benefits for human health. Fragaria chiloensis is a native wild berry species from Chile that develops a white/pink receptacle and white flesh at the ripe stage. Changes in color parameters, anthocyanins, secondary metabolites (phenolics, flavonoids), and total antioxidant capacity were followed during the development and ripening of F. chiloensis fruit. The increment in color ‘a’ index takes place in parallel with anthocyanins rise and the reduction in phenolics, flavonoids, and antioxidant capacity. Good correlations were determined between color development, anthocyanins, and the expression of key phenylpropanoid/flavonoid and anthocyanin pathway genes. To investigate the role of ABA on color development, detached immature fruit (C2 stage) were treated with exogenous ABA and stored at 20 °C. Fruit color development was accelerated by ABA treatment compared to non-treated fruit, and consistent with that, the increment in the accumulation of anthocyanins and transcripts of phenylpropanoid/flavonoid, and anthocyanin pathways genes such as FcPAL, FcCHS, and FcANS were observed. This suggests that ABA promotes transcriptional changes that lead to the color formation on this non-climacteric fruit.

Effect of processing treatments on digestibility and physicochemical properties of ready‐to‐cook breakfast mixes

Increasing metabolic disorders and changing lifestyles have created an increased demand for healthy convenience food, especially breakfast. The study aims to identify an ideal processing method to formulate a Ready-to-Cook savory wheat (Dalia) porridge with reduced starch digestibility and enriched protein and fiber content. Pressure-cooking (WP), autoclaving (WA), drum-drying (WD), flaking (WF) and toasting (WT) were adopted for instantization. The energy distribution was as per the guidelines of the American Diabetes Association. Processing resulted in reduced cooking time, changes in color parameters, increased water absorption and solubility. Complete gelatinization of starch was observed in all samples except WA and WT. Resistant starch content increased in all samples (8.95-16.70 g/100 g) except WD and WT. The estimated glycemic Index (eGI) ranged from 65.8-54.8, with maximum eGI shown by WD and minimum by WA. Increased in vitro protein digestibility 5-10% was observed. All the porridge showed good sensory characteristics and acceptability.

Synthesis and study of ferri-diopside ceramic pigments

The article reports the mineralogical composition, structural features and changes in color parameters of iron-containing diopside pigments. The source of SiO2 in these pigments was SiO2nH2O with a particle size in the range of 2–7 m, which is much more reactive than conventionally used quartz sand. A series of ceramic pigments on the basis of stoichiometric diopside in the system CaO–Fe2O3–MgO–SiO2 was synthesized via solid-state high temperature sintering at 1000, 1100 and 12000C. The resulting ceramic pigments were examined by powder X-ray diffraction, infrared spectroscopy, electron microscopy, electron paramagnetic resonance and Mössbauer spectroscopy. The color characteristics were measured using spectrophotometry method. It was found that multiphase ceramic pigments were obtained under the synthesis conditions, which contain diopside, wollastonite, cristobalite, akermanite and periclase in various proportions. The synthesized ceramic pigments are brown and beige in color, depending on the content of Fe2O3 additive, firing temperature and phase composition. The synthesized pigments can be used for staining of ceramic glazes.

Effects of ultrasound on the formation of oxidative pigments in a model red wine solution containing glutathione

Xanthylium cations and its ethyl ester are important pigments derived from (+)-catechin and glyoxylic acid in wine. In this paper, ultrasound treatment was applied in model wine containing glutathione to study its effects on the formation of xanthylium cation pigments triggered by free radicals from the ultrasound cavitation. The changes in color parameters, concentration of pigment compounds and free radicals were investigated during wine storage by the means of ultraviolet visible (UV–vis) spectrophotometer, colorimeter, high performance liquid chromatography with mass spectrometry (HPLC-MS) and electron paramagnetic resonance (EPR), respectively. Results indicate that longer ultrasonic treatment in conjunction with glutathione can significantly enhance the formation of xanthylium cation pigments and accelerate the red wine color evolution, and no extra (+)-catechin was involved, which might be attributed to the stronger 1-hydroxyethyl radicals intensity induced by ultrasound irradiation. In summary, ultrasound treatment can accelerate the oxidative coloration of wine with GSH during ageing, which would contribute to well understand the changing mechanism of wine color properties modified by ultrasound.

Efficacy of non-hydrogen peroxide mouthrinses on tooth whitening: An in vitro study.

To evaluate the tooth whitening efficacy of non-hydrogen peroxide containing mouthrinses. Forty incisors were randomly assigned into four groups. Four whitening mouthrinses, Oral-B 3D White Luxe/Procter & Gamble (WL), Listerine Advanced White/Johnson & Johnson (AW), Colgate Max White/Colgate (MW), and iWhite Whitening Mouthwash/Sylphar (iW), were used over a four-week period. Color changes of L*, a*, b*, ΔE*ab , and ΔE00 , were recorded by a digital spectrophotometer (Spectroshade Micro/Mht), at baseline and intermediate week-intervals. Data were statistically analyzed using repeated measures ANOVA at α=0.05. The first-week mean change of L* was 0.76 and significantly different from the baseline for all solutions, without any further changes. Correspondingly, a* decreased by -0.36, while b* increased by 0.48, contributing to a color change of 1.15 ΔE*ab or 0.91 ΔE00 . No differences were found among the solutions in respect to color-parameter changes (p > 0.05). Differences among time intervals were significant (p< 0.05) and mainly observed between the baseline and the following week-measurements. There was no statistically significant time-solution interaction (p > 0.05). Non-hydrogen peroxide whitening mouthrinses, slightly contribute to tooth whitening, by removing superficial staining, without any further tooth bleaching effect. Non-hydrogen peroxide containing whitening mouthrinses, despite having a quick initial action, reach their ceiling relatively soon. Their effectiveness is barely perceptible and definitely inferior to other professional tooth bleaching methods. Thus, they can only be considered as a supplementary way of keeping teeth whiter, mainly by preventing recurrent tooth discoloration.

The Effects of Salicylic, Folic and Ascorbic Acid Treatment on Shelf Life Quality of Broccoli Florets

This study aims to investigate the effect of Salicylic acid (2 mM), Folic acid (5 mg L−1) and Ascorbic acid (2 mM) treatments on the shelf life and quality of 'Belstar F1' broccoli variety. Treated broccoli heads were stored at 21±2˚C for 4 days in plastic containers with lids. It is determined that at the end of the storage period, the lowest weight loss (2.74%), total soluble solids (8.07%), pH value (7.14) and the highest amount of titratable acidity (0.12%) were found in the group treated with ascorbic acid and the least change in color parameters (L*; 29.41, a*; -4.59, b*; 10.78) and the highest total chlorophyll content (0.32 mg/g) in the group treated with folic acid. It is thought that the effects of ascorbic acid, salicylic acid and folic acid treatment at postharvest storage period should be investigated in detail in molecular and biochemical studies for more concrete data.

Antibacterial Activity of Caffeic Acid Combined with UV-A Light against Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium, and Listeria monocytogenes.

The aim of this study was to evaluate the antibacterial activity of caffeic acid (CA), which is a natural polyphenol, combined with UV-A light against the representative foodborne bacteria Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes. Data regarding the inactivation of these bacteria and its dependence on CA concentration, light wavelength, and light dose were obtained. E. coli O157:H7 and Salmonella Typhimurium were reduced to the detection limit when treated with 3 mM CA and UV-A for 3 J/cm2 and 4 J/cm2, respectively, and 5 J/cm2 treatment induced 3.10 log reduction in L. monocytogenes. To investigate the mechanism for inactivation of Salmonella Typhimurium and L. monocytogenes, measurement of polyphenol uptake, membrane damage assessment, enzymatic activity assay, and transmission electron microscopy (TEM) were conducted. It was revealed that CA was significantly (P < 0.05) absorbed by bacterial cells, and UV-A light allowed a higher uptake of CA for both pathogens. Additionally, CA plus UV-A treatment induced significant (P < 0.05) cell membrane damage. In the enzymatic activity assay, the activities of both pathogens were reduced by CA, and a greater reduction occurred by use of CA plus UV-A. Moreover, transmission electron microscopy (TEM) images indicated that CA plus UV-A treatment notably destroyed the intercellular structure. In addition, antibacterial activity was also observed in commercial apple juice, which showed results similar to those obtained from phosphate-buffered saline (PBS), resulting in a significant (P < 0.05) reduction for all three pathogens without any changes in color parameters (L*, a*, and b*), total phenolic compounds, and DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity. IMPORTANCE Photodynamic inactivation (PDI), which involves photoactivation of a photosensitizer (PS), is an emerging field of study, as it effectively reduces various kinds of microorganisms. Although there are several PSs that have been used for PDI, there is a need to find naturally occurring PSs for safer application in the food industry. Caffeic acid, a natural polyphenol found in most fruits and vegetables, has recently been studied for its potential to act as a novel photosensitizer. However, no studies have been conducted regarding its antibacterial activity depending on treatment conditions and its antibacterial mechanism. In this study, we closely examined the effectiveness of caffeic acid in combination with UV-A light for inactivating representative foodborne bacteria in liquid medium. Therefore, the results of this research are expected to be utilized as basic data for future application of caffeic acid in PDI, especially when controlling pathogens in liquid food processing.

Effect of whitening toothpastes containing activated charcoal, abrasive particles, or hydrogen peroxide on the color of aged microhybrid composite

This study aimed to assess the effect of different whitening toothpastes containing activated charcoal, abrasive particles or hydrogen peroxide on the color of aged microhybrid composite. In this in vitro, experimental study, 45 composite discs (2 mm × 7 mm) were fabricated of a microhybrid composite. They underwent accelerated artificial aging for 300 h, corresponding to 1 year of clinical service. The composites were then randomly divided into five groups (n = 9). One group served as the control and underwent tooth brushing with distilled water. The remaining four groups underwent tooth brushing with Colgate Total whitening (Gt), Colgate Optic White (Go), Perfect White Black (Gp) and Bencer (Gb) toothpastes in a brushing machine The International Commission on Illumination values (Lm, am, bm) were determined using a spectrophotometer. Color change (ΔE) calculated based on this formula: ΔEm= ([ΔLm] 2 + [Δam] 2 + [Δbm] 2)½. The differences were defined by ΔE1 (after aging-baseline),ΔE2 (after brushing-after aging) and ΔE3 (after brushing-base line). ΔE1 were evaluated to ensure that color mismatch had occurred (ΔE1 > 5.5). Difference in (L, a, b) parameters after aging and after tooth brushing in each group, color parameter changes (ΔL2, Δa2, Δb2, ΔL3, Δa3, Δb3) and ΔE2 and ΔE3 were analyzed and compared using Wilcoxon test and independent sample median test at P = 0.05 level of significance. The color parameter changes, ΔE3 and Δ E2 were not significantly different among the five groups (P > 0.05). In Gp and Gb charcoal a*, b*, and L* after tooth brushing (P < 0.05). In Colgate Optic group, the a* parameter significantly decreased while the L* parameter significantly increased (P < 0.05). The results showed that there is no significant difference in the color change of Spectrum composite following tooth brushing with different whitening toothpastes for two weeks. It should be noted that Δ E3 reached to <3.3 only in charcoal whitening toothpastes.

Investigation of the Effect of Different Immersion Times of Anchovy Fillets in Liquid Smoke Flavoring on Color by Image Analysis

ABSTRACT This study aimed to monitor the color changes of anchovy during the hot smoking process. For hot smoking, liquid smoke flavoring (LS) was used as an alternative to traditional smoking. The change in color was determined using the computer-based imaging system (CBI). L*, a*, and b* values were measured when anchovy samples were raw, after brining, after LS immersion, and after cooking. Various immersion times of 1, 2, and 3 minutes were tested, and resulting groups were coded as 1LS, 2LS, and 3LS, respectively. It was concluded that L*, a*, and b* values of the smoked groups did not exhibit any statistically significant difference after immersion (p > .05). Interestingly, the changes in color parameters after cooking were found to be statistically significant (p < .05). Group 1LS had a lighter color than the other LS groups upon cooking. The Delta E value of the samples also increased during the process. During the smoking process of anchovies, no color changes as a result of salting and dipping in liquid smoke solutions for different durations were observed until the final cooking step. The results of this study can help in improving the processing, preservation, and marketing aspects of smoked anchovy by controlling the color properties. Since anchovy is a small fish, smoking by traditional methods is quite challenging. Therefore, LS applications are economical and practical for these kinds of species. Although there have been studies related to the use of LS on anchovies, no research has monitored their color change.

Effect of dielectric barrier discharge plasma excitation frequency on the enzymatic activity, antioxidant capacity and phenolic content of apple cubes and apple juice

Cold plasma is a potential alternative to traditional thermal conservation methods because of its high efficiency in the preservation and retention of quality parameters. The objective of this study was to evaluate the application of atmospheric cold plasma on some qualitative aspects of apple cubes and apple juice. The research used dielectric barrier discharge plasma and studied different excitation frequencies of plasma: 50, 200, 400, 600, and 900 Hz. The effects of plasma application were evaluated on enzymatic activity (PPO and POD), total phenolic compounds, antioxidant capacity, and colorimetry. Plasma treatment partially inactivated the polyphenol oxidase enzyme in apples cubes and juice. Inactivation of peroxidase occurred only in apple juice. Total phenolic content and antioxidant capacity presented no significant difference between the treated and control samples of apple cubes, while significant changes were observed in apple juice. The changes in color parameters were slight and did not compromise the product quality. Plasma application was able to partially inactivate the enzymes responsible for browning while maintaining the quality and sensory properties of apple cubes and juice.

Ocena produktów mięsnych z dodatkiem wybranych substancji bioaktywnych

Implementation of bioactive antioxidant compounds into the product can enhance the product quality and extend the shelf-life of meat and meat products. The aim of the study was to evaluate the effect of fish oil, lyophilisate of tomato concentrate and thyme extract additives on the oxidation stability, colour parameters and sensory quality of the meat product during its storage. This study was conducted on a model meat product in the form of meatballs made from minced: chicken breast muscles, turkey drumstick muscles, pork meat, with addition of eggs, wheat bread, salt, black pepper and herbal pepper. After heat treatment, the samples were cooled and were stored under vacuum at 4 ºC for 14 days. It was shown that addition of 2 % freeze-dried tomato concentrate to meatballs resulted in cooking yield increase during heat treatment, decrease of pH and changes in colour parameters as well as stabilization of colour during storage. The addition of tomato concentrate also improved the sensory quality and also influenced the maintenance of the overall quality during the initial storage period. The addition of 4 % thyme extract to meatballs stopped oxidative changes and did not significantly affect the technological and sensory quality. Meatballs with the addition of cod liver oil and thyme extract were characterized by the highest overall quality after heat treatment. Based on sensory evaluation and oxidative status, meatballs can be stored for up to 7 days.

Effect of Plasma-Activated Water on the Microbial Decontamination and Food Quality of Thin Sheets of Bean Curd

Thin sheets of bean curd may serve as an excellent source of nutrition for microorganisms and are therefore prone to contamination, which can be harmful to public health. This study evaluated the influence of plasma-activated water (PAW) on the microbial load and food quality of thin sheets of bean curd. Treatment for 30 min with PAW that was activated for 90 s reduced the microbial count by 1.26 and 0.91 log10 CFU/g for total aerobic bacteria and total yeasts and molds on thin sheets of bean curd, respectively. The effect of PAW on microbial inactivation strongly depended on the activation time for PAW generation and the soaking time of the thin sheets of bean curd in PAW. Further, PAW could maintain total isoflavone content, sensory properties, and most of the textural properties of the thin sheets of bean curd. Although PAW treatments caused significant changes in color parameters of the thin sheets of bean curd, the appearance acceptance was not significantly influenced. This work highlights the potential application of PAW in the microbial decontamination of thin sheets of bean curd.

Effect of sodium alginate and carboxymethyl cellulose edible coating with epigallocatechin gallate on quality and shelf life of fresh pork

The active edible coatings were prepared by incorporating epigallocatechin gallate (EGCG) into sodium alginate (SA) and carboxymethyl cellulose (CMC) to investigate the effect of SA-CMC-EGCG coatings on quality and shelf life of fresh pork stored at 4 ± 1 °C for 7 days. The antioxidant effects against lipid oxidation (TBARS), total volatile basic nitrogen (TVB-N) and antimicrobial activity against total viable counts (TVC) were analyzed. Besides, the changes in color parameters and sensory attributes of all pork samples were evaluated. The results showed that fresh pork coated with SA-CMC edible coating with EGCG had a significant inhibitory effect on its microbial growth (P < 0.05), lipid oxidation and TVB-N. SA-CMC-EGCG also increased the L* value and maintained a* value of pork during storage. Besides, the sensory scores of pork samples coated with SA-CMC-EGCG were significantly improved (P < 0.05). Therefore, using SA-CMC-EGCG edible coating could prevent decay and significantly increase the shelf life of fresh pork.

Combination of ultrasound and ultraviolet‐C irradiation on kinetics of color, firmness, weight loss, and total phenolic content changes in tomatoes during storage

A kinetic study was conducted to account for the changes occurring in color, firmness, weight loss, and total phenolic content of tomatoes subjected to combined ultrasound technology (40 kHz, 13.78 W/L) and ultraviolet-C radiation (639.37 µw/cm2) treatment for 28 min. Combined treatment delayed ripening, increased firmness, weight loss, and induced total phenolic content retention of tomatoes compared to untreated samples. The change in color parameters of hue angle and chroma was described using the fractional conversion and zero-order models, respectively. Fractional conversion kinetic model was also found suitable for firmness degradation, while the zero-order and first-order models were appropriate for change in weight loss and total phenolic content retention prediction, respectively. Activation energy for measured parameters ranged from 121.29 to 199.70 kJ/mol at a temperature range of 33.76–37.12ºC, and showed highest sensitivity to treatment temperature in reduced ranking for firmness degradation, weight loss, total phenolic content retention, hue angle, and chroma. Practical applications The research provides a new method for postharvest handling of fruits and vegetables. The method utilizes ultrasound technology and ultraviolet-C radiation in combination and finds potential application in industries for shelf life extension during the storage, processing, and supply chain management of fruits and vegetables. However, the method may result in undesirable changes like weight loss, physical softening, or bioactive content degradation. Optimized parameters of the method are essential for loss minimizations and cost-effective practical applications. A thorough understanding of the influence of temperature of the system, treatment time, ultrasound acoustic energy density, and ultraviolet-C dosage on the quality properties of tomatoes and their change kinetics through fundamental approach modeling as presented in this research, is a step toward optimization of the technology.

Influence of oenological tannins on malvidin-3-O-monoglucoside copigmentation in a model wine solution

Aim: The aim of the study was to evaluate the effects of five different oenological tannins on the color of a malvidin-3-O-monoglucoside solution, and thereby assess the effectiveness of these tannins as copigments.Methods and results: Solutions containing malvidin-3-O-glucoside and different doses of copigments were prepared. The malvidin-3-O-glucoside concentration of the solutions, and color parameters, were measured after 1 and 7 days.Conclusions: On days 1 and 7, a decrease in lightness and hue, and an increase in chroma, absorption at 520 nm and wavelength of maximal absorption were observed in solutions containing the oenological tannins. A decrease in malvidin-3-O-glucoside concentration in the tannin-containing solutions compared with the control solution was detected on day 7. The extent of this decrease depended on the specific tannin. Some changes in color parameters on day 7 compared with day 1 were observed, which were probably due to the formation of new pigments. The total color difference between the different malvidin-3-O-glucoside solutions and a pure white solution was calculated to estimate the effectiveness of the different tannins as copigments.Significance and impact of the study: These results prove that supplementation with oenological tannins is a viable option for improving the color of red wines. A copigmentation index is proposed for measurement of the effectiveness of copigments.

Influence of Zirconia-Coated Bioactive Glass on Gingival Fibroblast Behavior

The objective of this study was the development of a bioactive glass coating on zirconia (Zr) to modulate the gingival fibroblast phenotype. For this purpose, Biosilicate® (BS) particles in a water/isopropyl alcohol (1:1) vehicle (6 mg/mL) were applied to zirconia discs followed by thermal treatment at 1100 °C for 20 min. The surface topography (SEM), chemical composition (EDX), surface roughness (Ra; confocal microscopy), surface free energy (goniometry), and color alteration (UV-vis spectrophotometry) were assessed (n=6). Thereafter, L929 fibroblasts were seeded onto Zr and Zr+BS discs, and cell proliferation (Alamar Blue; n=6), morphology (SEM; n=2), migration (wound healing; n=4), and collagen synthesis (Sirius Red; n=6) were evaluated up to 7 days. Data were analyzed by ANOVA/Tukey tests (a=5%). A homogeneous coating consisting of Si, Na, O, and Ca was detected on the Zr surface after thermal treatment with BS, which led to a significant increase in surface roughness and free energy (p<0.05). No change in color parameters was observed (p>0.05). Cells seeded on the Zr+BS surface featured increased proliferation, collagen expression, and migration capability in comparison with those cultured on plain Zr (p<0.05). SEM images revealed that cell spreading occurred faster in the presence of BS. Therefore, it was concluded that thermal treatment of the Zr surface with BS led to the deposition of a bioactive coating, which induced gingival fibroblast spread, proliferation, migration, and collagen expression in vitro.