CIELAB Parameters Research Articles

Effect of monomer type on the C[dbnd]C degree of conversion, water sorption and solubility, and color stability of model dental composites

ObjectiveThis study has investigated the influence of BisGMA, BisEMA, BisEMA 30, and two UDMA-based monomers (UDMA and Fit 852), with TEGDMA as co-monomer, on the degree of conversion, water sorption, water solubility, and optical properties of experimental dental composites. MethodsMaterials were formulated at 70/30 molar rations using BisGMA, BisEMA, BisEMA 30, UDMA or FIT 852, as base monomers, combined with TEGDMA. 60wt% of silanated-glass particles was added. Degree of conversion (DC) and polymerization kinetics were monitored using Fourier-transformed infrared spectroscopy in the near-IR range. Water sorption (Wsp) and solubility (Wsl) were assessed using mass variation after 60days water storage. Color was evaluated using a digital spectrophotometer, applying the CIELab parameters 24h after dry storage and 60days after water immersion to calculate ΔE values. All data were analyzed using ANOVA and Tukey’s test (pre-set alpha=0.05). ResultsThe BisGMA-based co-monomer mixture presented the lowest DC (62±1%), whereas BisEMA 30 had the highest DC value (95±2%). The highest Wsp was observed for BisEMA 30 (12.2±0.8%), and the lowest for BisEMA (0.4±0.1%). BisEMA has shown the lowest Wsl (0.03±0.01%) and BisEMA 30 the highest one (0.97±0.1%). The ΔE values showed that BisEMA 30 (7.3 color units) and Fit 852 (3.8 color units) altered the color stability providing ΔE>3.3, which is considered clinically unacceptable. ConclusionsThe chemical composition and structure of the base monomer influenced the degree of conversion, water sorption, water solubility, and color stability. Considering the overall results, it is possible to state that the base monomer BisEMA mixed with the co-monomer TEGDMA presented the best performance in terms of all the parameters tested. SignificanceThe resin matrix composition might influence physical property degradation processes and color stability of dental resin composites. Formulations based on BisEMA seem most promising for materials’ development.

여러 색상으로 적층된 복합레진의 색과 투명도

The purpose of this study was to evaluate the color and translucency of multi-shade layered composites. To simulate a class IV direct composite restoration, 4 mm-thick disc-shaped specimens (15 mm in diameter) were prepared. Z250 (A2) or Z350XT (A2 enamel (E), body (B), and dentin (D)) were bulk-filled. Both Z350XT/A2E and Z350XT/A3D were bi-layered, in which the thickness of Z350XT/A2E was increased from 1.0 mm to 3.0 mm with an increment of 1.0 mm while the thickness of Z350XT/A3D was decreased. Total thicknesses of the sandwiched specimens were maintained at 4 mm. The CIELAB parameters (L*, a*, and b*) of specimens were measured using a spectrophotometer to calculate the color difference (ΔE) without background, and to calculate translucency parameter (TP) on a white or black background. One-way ANOVA and post-hoc Tukey’s test were employed for statistical analysis. ΔE between Z250 (A2) and three different shades of Z350XT (A2E, A2B, and A2D) were greater than 3.3, that was an unacceptable level. ΔE between a bulk-filled specimen with Z350XT/A2B and layered specimen with the Z350XT/A2E and Z350XT/A3D was the lowest in a specimen of A2E 2 mm + A3D 2 mm (p0.05). Statistically significant difference was found between the TP values of bulk-filled specimens (p0.05). The TP values of layered specimens increased with increasing the thickness of enamel shade (p0.05). Within the limitation of this in vitro study, the combined layering with 2 mm-thick A2E and 2 mm-thick A3D is recommended for the class IV direct composite restoration with a Z350XT/A2 shade.

Effect of the addition of peach palm (Bactris gasipaes) peel flour on the color and sensory properties of wheat bread

The aim of this study was to evaluate the color and sensory characteristics of bread made with different levels of peach palm peel flour (PPPF). This flour was added into breads with a proportion of 2.5-10% (w/w), and studied its effect on total carotenoids, CIELab parameters, and sensory characteristics of bread. Results showed that PPPF supplementation increased the carotenoid content of bread. The color test showed that high levels of PPPF were associated with a decreased L* and H°, while, browning index (BI), increases. Sensory evaluation ratings indicated that bread with acceptable quality attributes can be prepared from wheat flour fortified with PPPF up to 5% level. Thus, peach palm peel, a by-product from the peach palm processing, could be utilized for the preparation of wheat breads.

Agronomic and physicochemical fruit properties of ‘Big Top’ nectarine budded on peach and plum based rootstocks in Mediterranean conditions

Agronomic and physicochemical fruit properties of ‘Big Top’ nectarine were evaluated in the Ebro Valley (Zaragoza, Spain), under replant and heavy-calcareous soil conditions typical of the Mediterranean area. Fruits were harvested at commercial maturity from trees budded on four peach-almond hybrids (Prunus amygdalus×Prunus persica): Adarcias, Felinem, GF 677 and Mayor; two P. persica×Prunus davidiana hybrids: Barrier and Cadaman; two hexaploid plums: Adesoto (Prunus insititia) and Tetra (Prunus domestica); and one almond-plum hybrid (Prunus cerasifera×P. amygdalus): Replantpac. Significant differences among the different rootstocks were found for most of the fruit quality traits analyzed at harvest maturity. The average of the four years of study showed that the brightest (high L* value) and most red colored skin fruits (high a* and b* values) were found on GF 677, while the lowest b* and h were recorded on Tetra and Felinem, respectively. Adesoto, GF 677 and Replantpac induced good fruit quality traits based on anthocyanins, Vitamin C, relative antioxidant capacity and/or total phenolic content (TPC). GF 677 also showed higher values on cumulative yield (CY) and yield efficiency (YE), with no significant differences with Replantpac for CY and Adesoto for YE. Barrier and Cadaman seem to delay maturity of ‘Big Top’ fruits based on flesh firmness (FF), titratable acidity (TA) and CIELAB parameters, and showed lower TPC and anthocyanins, which could be partly explained due to their worst adaptation to calcareous soil conditions. Results from this study underlined the important relationships between plant adaptability and fruit quality traits.

Comparative evaluation of physical parameters of salted goat and sheep meat blankets “mantas” from Northeastern Portugal

Physical properties and color parameters were compared in goat and sheep meat blankets “mantas” obtained after salting and air-drying processes at 8–10 °C for 48 and 120 h, respectively. Animal which were used in preparation process did not meet the requirement of age and weight to be involved into the classifications of Protected Designation of Origin or Geographical Indication established by Portuguese regulations. pH, water activity (aw), water holding capacity (WHC) and texture were assessed in longissimus dorsi muscle of fresh meat samples. The processes of product fabrication consisted of six stages: ageing, deboning and obtaining of mantas, salting, stumbling, washing, air drying and vacuum packaging. Color CIELAB parameters were monitored during salting and air-drying processes at subscapularis and semimembranosus muscles. Significant differences were found between physical characteristics of fresh meats; texture and WHC were the factors most influenced by ageing. Sheep meat blankets reached values of L*, b* and C* higher than the goat but a lower value of a*.

Influence of type and shelf-life on two brands complementary food in color, vitamins, and sensory evaluation

The aim of our study was to measure the color by system CIELAB, sensory analysis, and determination of vitamins in children vegetable complementary feeding (carrot, vegetable mix) with the option to extend shelf life from eighteen to twenty-one months. Complementary children food was obtained from private factory in the Czech Republic. In this research there were used only carrot and vegetable mix samples. To determine the color changes by system CIELAB and determination of vitamins, samples of mash were analyzed before filling into jars and sterilization, and then immediately after sterilization. Further analyzes were performed for twenty-one months, with run of every three months (p <0.05). The comparison of color CIELAB parameter L* (lightness) for two process steps: raw mash and sterilized mash; there were significant differences when processing (p <0.0001, r2 = 0.9983). Mainly, the parameter L* (Lightness) showed statistically significant differences in carrot and garden mix (p <0.05). β-carotenes such as provitamin A, is in food of plant origin stable substance in the absence of air. Storing time had significant influence on contain of β-carotenes, the mean content during twenty-one months was 0.862 mg.100g-1 (p <0.05, r2 = 0.2300). There were no significant differences in dark storing (p >0.05, r2 = 0.1097). The sensory evaluation showed statistical differences in all descriptors (color saturation, uniformity of color, consistency and homogeneity) (p <0.05) in course of months of storage time and storage conditions (daylight-dark). The results can be recommended to manufacturers, extending the period of minimum shelf life of the required three months to twenty-one months due to instability as characteristics of color and textural properties which were obtained.

Impact of pH and temperature on the colour and betalain content of Colombian yellow pitaya peel (Selenicereus megalanthus).

The effects of different pHs (4, 5 and 6), temperatures (4, 20 and 80°C) and storage (up to 12days) on differential tristimulus colorimetry and betalain content related to the colour of yellow pitaya (Selenicereus megalanthus) have been investigated. The peel of the yellow pitaya was extracted with different solvents to see its colorant capacity. Highly-acidic extracts (pH4) showed the lowest betalain content, chroma (C* ab = 60 against 70) and the yellow component of the colour (b*). Storage temperature manifested a great influence on CIELAB parameters when yellow pitaya peel was added to highly-acidic foodstuffs, with a tendency towards red hues (h ab , from 100° to 85°) and remarkable changes on lightness (L*, from 90 to 75) as temperature increased. However, low-acidic extracts (pH5 and 6) were superior from a colour stability standpoint, not being influential the temperature of storage. All colour changes according to pH and temperature were visually appreciable by human eyes (∆E* ab >3). New opportunities for diversification of colorant market could be possible by employing yellow pitaya peel as natural resource.

EVALUATION OF INTRINSIC COLOR STABILITY OF FACIAL SILICONE ELASTOMER REINFORCED WITH DIFFERENT NANOPARTICLES

INTRODUCTION: Maxillofacial defects are located in a highly visible body area that is identified with one’s identity. An aesthetic and comfortable maxillofacial prosthesis relieves many concerns of the patient and may improve quality of life. Silicone elastomers are more color stable than other materials used in maxillofacial prostheses thus many authors investigated the color stability of those materials under weathering conditions. OBJECTIVES: This study evaluates the effects of two types of nano-oxides particles at different concentration on the color stability of pigmented silicone MDX4-4210 maxillofacial prosthetic elastomers after artificial aging. MATERIALS AND METHODS: MDX4-4210 silicone elastomer specimens were fabricated. The control group was incorporated with intrinsic coloring agents, one of nanoparticles group was incorporated with intrinsic coloring agents and titanium oxide nanoparticles (TiO2) at different concentration (2%, 2.5 and 3%), other nanoparticles group was incorporated with intrinsic coloring agents and aluminum oxide nanoparticles (AL2O3) at different concentration (2%, 2.5% and 3%). All specimens were exposed to sunlight, sweat and ultraviolet light for one months. Easy shade spectrophotometer was used to determine the CIELAB (L*a*b*) parameter before and after aging of each specimen, and the values were noted. RESULTS: The majority of the color changes in all groups were above 3.3 ΔE* units, which indicates that they were visually observed color change. After one month aging period TiO2 group was more stable than Al2O3 regarding ultraviolet light. Regarding sweat TiO2 group showed more color alteration. Al2O3 group showed lower color alteration on exposure to sunlight. CONCLUSIONS: Artificial aging procedures affected the color stability of the maxillofacial silicone with or without nanoparticles incorporation. KEY WORDS: Titanium oxide, intrinsic color, Color stability, artificial aging, Silicon elastomer.

UV-Curable Coating Process on CMYK-Printed Duplex Paperboard, Part II: Effects of Nano-TiO2 Modification

The influence of TiO2 nano-particles (nano-TiO2) was studied relative to the mechanical and optical properties of CMYK printed paperboard after coating with a UV-curable varnish. Commercial duplex paperboard (glazed grayback paperboard, 230 g/m2) was printed with a CMYK offset printing process. Board samples were coated with a nano-TiO2 modified UV-curable varnish at four treatment levels (0, 0.2, 0.5, and 1%) using an industrial screen-coating machine. The samples were then dried using a UV lamp in an industrial UV drying machine. Sample discoloration was measured spectrophotometrically using CIELab parameters (L*, a*, b*, and ΔE) before and after coating. The whiteness, brightness, fold, and tear resistance of the ink films were also measured. The nano-treatment had a significant effect on the relative optical parameters, which resulted in increasing the lightness of the treated samples. Color change (ΔE) was recorded for all tested samples, and an unperceivable change was observed in case of the nano-treatment with 0.2% as the end value. The weakly perceivable changes were found in the cases of treatment with 0.5 and 1% nano-intensities. The nano-TiO2 treatment significantly improved the fold and tear resistance of the samples.

Differentiation of wines with the use of combined data of UV–visible spectra and color characteristics

UV–visible spectra and color parameters of monovarietal wines with orthogonal partial least square-discriminant analysis (OPLS-DA) were shown to be practical and rapid methods for classification purposes. Red and white wines from the 2006–2009 vintages were characterized in terms of color, anthocyanin content and UV–visible spectra. Syrah and Cabernet Sauvignon wines had high color density and intensity. Kalecik Karası wines had the highest CIELab parameters and the lowest color density. Boğazkere and Öküzgözü wines showed similarities with respect to their high red color parameters and were distinct from other wines. Merlot, Syrah and Öküzgözü wines had the highest total anthocyanin content (61.9–55mg/L as median values). White wines made from Chardonnay, Muscat and Emir grapes were found to have different color characteristics. The vintage-based discrimination of red wines was mostly apparent in total anthocyanin contents. Different UV wavelength regions were found to be effective in classification with respect to variety and vintage. Correct classification rates in the validation set were 100% and 75%, for varietal and vintage classifications, respectively. This study demonstrated the potential of combination of UV–visible spectra and color characteristics to be used in the authentication of wines.

Multi-beam laser-induced hydrodynamic shock waves used for delivery of microparticles and liquids in skin.

Laser radiation is often used to provide micro and nanoparticle delivery into the skin for medical and cosmetic purposes. This technique inherently has limited speed and effective penetration. We proposed and investigated a new method of rapid delivery of solid microparticles, nanoparticles and liquids into tissue through multiple microchannels created by a fractional laser microablation (FLMA) using Er:YAG-laser. The dependence of microchannel depth on laser pulse temporal structure and number of pulses and dermal coloration changes are studied in this paper. Microchannels created in the porcine skin in vitro by a fractional Er:YAG-laser were used to deliver Zirconium oxide (ZrO2) microparticles or hydrocortisone solution. Each laser pulse consisted of subpulses. Number of laser pulses (Np) and subpulses (Nsp) can be adjusted. The enhancement of delivery is expected due to hydrodynamic impact of laser pulse on the layer of the aqueous suspension of the particles or hydrocortisone solution placed on the skin surface. For color investigation, we used standard CIE Lab parameter analysis. The relationship between microchannel depth in the skin and number of laser pulses and subpulses was established. We found that free filling of microchannels with ZrO2-particle suspension has a low speed of ∼4 × 10(-5) mm/s. Particle delivery into microchannels induced by the hydrodynamic shock waves generated by Er:YAG-laser pulses is carried out with a high speed of 28.5 mm/s. We also found that skin color at ZrO2 -particle delivery differs from color of the intact skin, namely: the parameter L, which characterizes the "lightness" increased by 9 ± 1%; parameter a, which characterizes the "redness" decreased by 38 ± 4%; and parameter b, which characterizes the "yellowness" decreased by 21 ± 2%. The effective delivery of hydrocortisone was demonstrated using fluorescence method technique. Multi-beam laser-induced hydrodynamic shock waves generated by Er:YAG-laser pulses on the layer of the aqueous suspension of the particles or solution of a high molecular weight drug placed on the skin can be used for their rapid delivery into the skin.

Chemometric and phenolic attributes of blended wines assessed by multivariate techniques

The aim of the study was to investigate the quality of blended wines produced from Vitis vinifera L. Cabernet Sauvignon, Merlot and Sauvignon blanc grapes. Wines were processed according to accepted conventional methods for white and red wines. Blended wines were produced with different ranges (25, 50, 75 and 100%) of Cabernet Sauvignon, Merlot and Sauvignon blanc wines. Produced wines were evaluated for total phenols (mg/L), total tartaric esters (mg/L caffeic acid), total flavonols (mg/L quercetin), chemometric parameters such as D280%, D420%, D520%, D620%, dA%, CD%, T, CI%, R%, Y% and B%, CIELAB parameters, protein, total and volatile acidity. Analyses on an n-dimensional scale demonstrated the relationships among the wines of different grape origins and different blending ratios. On the basis of these differences, two main groups were plotted using principal component analysis and cluster analysis. The results demonstrate the possibilities of optimizing wines on the basis of defined parameters. Copyright © 2015 The Institute of Brewing & Distilling

Effect of different photoinitiators and reducing agents on cure efficiency and color stability of resin-based composites using different LED wavelengths

ObjectivesTo evaluate the effect of photoinitiators and reducing agents on cure efficiency and color stability of resin-based composites using different LED wavelengths. MethodsModel resin-based composites were associated with diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO), phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide (BAPO) or camphorquinone (CQ) associated with 2-(dimethylamino) ethyl methacrylate (DMAEMA), ethyl 4-(dimethyamino) benzoate (EDMAB) or 4-(N,N-dimethylamino) phenethyl alcohol (DMPOH). A narrow (Smartlite, Dentisply) and a broad spectrum (Bluephase G2, Ivoclar Vivadent) LEDs were used for photo-activation (20J/cm2). Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the cure efficiency for each composite, and CIELab parameters to evaluated color stability (ΔE00) after aging. The UV–vis absorption spectrophotometric analysis of each photoinitiator and reducing agent was determined. Data were analyzed using two-way ANOVA and Tukey’s test for multiple comparisons (α=0.05). ResultsHigher cure efficiency was found for type-I photoinitiators photo-activated with a broad spectrum light, and for CQ-systems with a narrow band spectrum light, except when combined with an aliphatic amine (DMAEMA). Also, when combined with aromatic amines (EDMAB and DMPOH), similar cure efficiency with both wavelength LEDs was found. TPO had no cure efficiency when light-cured exclusively with a blue narrowband spectrum. CQ-systems presented higher color stability than type-I photoinitiators, especially when combined with DMPOH. ConclusionsAfter aging, CQ-based composites became more yellow and BAPO and TPO lighter and less yellow. However, CQ-systems presented higher color stability than type-I photoinitiators, as BAPO- and TPO-, despite their higher cure efficiency when photo-activated with corresponding wavelength range. Clinical SignificanceColor matching is initially important, but color change over time will be one of the major reasons for replacing esthetic restorations; despite the less yellowing of these alternative photoinitiators, camphorquinone presented higher color stability.

Assessment of peach internal flesh browning through colorimetric measures

The purpose of this trial was to develop an objective internal flesh browning (IFB) assessment methodology for fresh peach. Six peach and three nectarine cultivars were used in this research. The fruit was maintained at 4°C for 21 and 31 days. They were then evaluated after three additional days of maintenance at 20°C. The differences in the CIELAB color parameters of the flesh ΔL*, ΔE*, Δh°*, ΔC*, Δa*, and Δb* were then assessed. ΔL* were assessed with both fresh fruit and fruit after postharvest treatments; after regression analysis, this resulted in the best CIELAB parameter to describe IFB. A trained sensory panel was used to corroborate the results. Between ΔL* and the panel assessment of IFB, was obtained the highest determination coefficient (R2=0.84). Furthermore, through a triangular test, it was determined that ΔL*=4.7 corresponds to the IFB peach flesh threshold, as perceived by the panel. Afterward, through a regression tree, four IFB categories were defined: (1) no IFB symptoms, when ΔL*<4.7; (2) incipient IFB symptoms, when 4.7≤ΔL*<8.0; (3) severe IFB symptoms, when 8.0≤ΔL*<21; and (4) extreme IFB symptoms, when ΔL*≥21. We recommend the use of ΔL* when objective phenotyping of IFB of peach flesh is required.

Usual and unusual CIELAB color parameters for the study of peat organic matter properties: Tremoal do Pedrido bog (NW Spain)

We have tested the practical application of color measurements in the study of organic matter properties (C and N content, C/N ratios, degree of peat humification-DPH) of a 335 cm long peat core sampled at Tremoal do Pedrido bog. Usual and unusual CIELAB color parameters were measured on samples that were sectioned at high resolution (slices of 1 cm in thickness). The objective of the study is twofold: (i) describe a rapid, cost-effective and non-destructive method of assessing peat properties without the need of extractions and chemical methods and (ii) contribute to further research on applied colorimetry using the well-known CIELAB coordinates: L*, a*, b*, C*ab and hab (‘usual CIELAB color parameters’) and the less well-known CIELAB parameters: [a* x b*], [a*/b*], [(a*/b*) x 1000], [1000 x a*/(L*+ b*)], [2000 x a*/(L* x b*)] and RLab= [a*(a*2+b*2)1/2 1010]/(b* x L*6) (‘unusual CIELAB color parameters’). Our findings show that L* and hab coordinates as well as [(a*/b*) x 1000], [2000 x a*/(L* x b*)] and RLab parameters give the best bivariate Spearman's correlations. Linear regression equations were calculated to predict peat properties from all CIELAB parameters under study and a notable fit (R2: 0.65-0.79) was obtained. The evaluation presented here indicates that the determination of usual and unusual CIELAB parameters offers potential for the study of peat organic matter properties and encourages the routine application of this methodology on other peat cores and organic soils.

Effect of Incorporation of Nano-Oxides on Color Stability of Maxillofacial Silicone Elastomer Subjected to Outdoor Weathering.

The aim of this study was to evaluate the effect of incorporation of two compositions of nano-oxides on color stability of intrinsically colored maxillofacial silicone elastomer subjected to outdoor weathering. Ninety Cosmesil M511 silicone elastomer specimens were fabricated. The control group was incorporated with intrinsic coloring agents (umber, brown, yellow), group A was incorporated with intrinsic coloring agents and nanosized titanium oxide (TiO2 ), and group B was incorporated with intrinsic coloring agents and nanosized zinc oxide (ZnO). For outdoor weathering, specimens were mounted on a treated plywood rack, and the assembly was weathered for 6 months. A GretagMacbeth Spectrolino spectrophotometer was used to determine the CIELAB (L*a*b*) parameter before and after weathering of each specimen, and the values were noted. The color change (∆E) values were analyzed by one-way ANOVA, Tukey's post hoc test, and paired t-test. The color change (ΔE*) for groups were control group > group A > group B. The control group (0.76 ± 0.32) and group A (0.47 ± 0.19) showed significant difference in the color change before and after weathering (p < 0.00001). Group B (0.03 ± 0.05) showed no significant difference in color change before and after weathering (p = 0.08). The present findings suggest that incorporation of nano-oxides improved the color stability of Cosmesil M511 silicone elastomer and also acted as an opacifier. ZnO-incorporated Cosmesil M511 specimens showed minimal or no color change and proved to be most color stable after being subjected to outdoor weathering.

Colourimetric variations in burnt granitic forest soils in relation to fire severity

Forest fires constitute a major environmental problem. Information about fire severity would enable the application of measures to offset the effects of forest fires on the ecosystems. In this study, we evaluated the usefulness of soil colour measurement as a rapid inexpensive method of determining fire severity. For this purpose, we subjected samples of granitic soils (Leptic Umbrisol, Umbric Regosol and Humic Cambisol) from different forest sites to laboratory controlled thermal shock. The thermal shock was performed in topsoil by the action of infrared lamps, which allowed reproducing similar temperatures to those reached in low, moderate and high severity fires. The maximum temperature and the degree hours (DH) reached during the heating were measured as indicators of fire severity. Changes in the colour of the soil and in the contents of organic matter and iron compounds were also analysed. Colour measurements were applied in three different processed burnt samples and results were compared in order to determine the best for the purpose of the study. The results obtained in the present study for granitic soils show that the values of the CIELAB parameters defining the colour of the surface of burnt granitic forest soils increased with the temperature and DH reached. Although the amount of organic matter was significantly correlated with all colour parameters and with temperature and DH reached, the Fe compounds were not significantly correlated with either CIELAB parameters, temperature or DH reached. Determination of variations in the organic matter content appears to be a reliable method of estimating the temperature and degree hours reached in granitic soils during burning.

Effect of Two Anti-Fungal Treatments (Metrafenone and Boscalid Plus Kresoxim-methyl) Applied to Vines on the Color and Phenol Profile of Different Red Wines

The effect of two anti-fungal treatments (metrafenone and boscalid + kresoxim-methyl) on the color and phenolic profile of Tempranillo and Graciano red wines has been studied. To evaluate possible modifications in color and phenolic composition of wines, control and wines elaborated with treated grapes under good agricultural practices were analyzed. Color was assessed by Glories and CIELab parameters. Color changes were observed for treated wines with boscalid + kresoxim-methyl, leading to the production of wines with less color vividness. Phenolic profile was characterized by HPLC analysis. Boscalid + kresoxim-methyl treatment promoted the greatest decrease on the phenolic content in wines.

Effect of different carotenoid-containing diets on the vitamin A levels and colour parameters in Iberian pigs' tissues: utility as biomarkers of traceability

Retinol and fat colour parameters in Iberian pigs fed on different carotenoid-containing diets were assessed. Thirty animals in two groups were considered: Iberian breed pigs fed on acorns and grass (Montanera) and on concentrate (Cebo). Carotenoids and retinoids were analysed in the diets and in plasma, liver and perirenal fat of the animals by HPLC and HPLC-MS. Retinol levels in plasma and fat were similar in Montanera and Cebo animals. The utility of retonids and colour parameters as traceability index was also explored. Retinoids in liver classified correctly 93% of the animals according to their diet L* and hab. CIELAB parameters of the perirenal fat discriminated correctly 78.6% of the animals according to their diet. L* values for the Montanera animals were significantly different (P<0.01) from those fed on concentrate. It can be claimed that the liver retinol profile and fat colour parameters can be useful for feeding traceability purposes in Iberian pigs breed in Montanera and Cebo.

Development of chitosan/montmorillonite nanocomposites with encapsulated α-tocopherol

Nanocomposites of chitosan (CS) were developed and characterized in a full factorial design with varying levels of montmorillonite (MMTNa) and encapsulated tocopherol (toc-encap). The structural properties (XRD, FTIR), morphology (TEM), hygroscopic properties (water vapour permeability, hydrophobicity, sorption isotherms) and optical properties (haze, CIELab parameters) of the resulting materials were evaluated. Toc-encap contents up to 10% influenced the intercalation of MMTNa in the CS matrix, resulting in films with reduced water vapour permeability (3.48×10–11(g/msPa)), increased hydrophobicity (ΔGHydroph |7.93–59.54|mJm−2) and lower equilibrium moisture content (EMC), thus showing potential for active food packaging materials. At levels above 10%, toc-encap agglomerates occurred, which deteriorated the properties of the resulting films, as shown with the TEM. As the toc-encap content increased, the films became slightly more yellow, more irregular and less transparent, with a higher haze index.