Chromatic characteristics and color-related phenolic composition of Brazilian young red wines made from the hybrid grape cultivar BRS Violeta (BRS Rúbea×IAC 1398-21)

The color characteristics and the phenolic composition related to color of young red wines elaborated with the hybrid grape cultivar BRS Violeta, developed for its adaptation to sub-tropical climates in Brazil, have been studied. These wines are characterized with a deep red-purplish color, reaching color intensity averaging 24 units. In spite of being young red wines elaborated with short maceration time, their content in total polyphenols was very high (around 3692. mg/L, as gallic acid equivalents), especially when compared to similar Vitis vinifera young red wines. Within polyphenols, anthocyanins predominated (around 2037. mg/L, as malvidin 3,5-diglucoside equivalents) and they were almost exclusively anthocyanidin 3,5-glucosides (ca. 97%), mainly built from B-ring tri-substituted anthocyanidins (delphinidin. >. petunidin. ≈. malvidin) and having high proportion of p-coumaroylated derivatives (ca. 28%) that confer higher stability. The content of hydroxycinnamic acid derivatives was also remarkable (ca. 95. mg/L, as caffeic acid equivalents) and unknown glucose derivatives of p-coumaric acid accounted for ca. 42% of total HCAD. Finally, these found flavonols were mainly based on myricetin whereas kaempferol derivatives were missing, their total content being within the ranges usually found for V. vinifera wines, but reaching their top values (ca. 91. mg/L, as quercetin 3-glucoside equivalents). All the aforementioned data suggest that Violeta wine could be considered an important dietary source of healthy polyphenols with a moderate alcoholic content (ca. 11.6%). © 2013 Elsevier Ltd.

Phenolic composition of the berry parts of hybrid grape cultivar BRS Violeta (BRS Rubea×IAC 1398-21) using HPLC-DAD-ESI-MS/MS

The grape is considered a major source of phenolic compounds when compared to other fruits and vegetables, however, there are many cultivars with distinct characteristics directly linked to phenolic profile. Thus, the present study aimed to identify and quantify, for the first time and in detail, the phenolic compounds present in the skin, flesh and seeds of BRS Violeta grape berry using combination of SPE methodologies and analytical HPLC-DAD-ESI-MS/MS. The study was extended to the different berry parts and the most important grape and wine phenolic families, and has revealed interesting features. Violeta grape has a very thick skin (46% of grape weight) that accumulated the most of grape phenolic compounds: great amount of anthocyanins (3930. mg/kg, as malvidin 3,5-diglucoside), together with also important amounts of flavonols (150. mg/kg, as quercetin 3-glucoside), hydroxycinnamic acid derivatives (HCAD; 120. mg/kg, as caftaric acid), and proanthocyanidins (670. mg/kg, as (+)-catechin); in contrast, it seems to be a low resveratrol producer. Violeta grape seeds accounted for similar proportions of low molecular weight flavan-3-ols (mainly monomers; 345. mg/kg, as (+)-catechin) and proanthocyanidins (480. mg/kg, as (+)-catechin). Violeta grape is a teinturier cultivar, but it only contained traces of anthocyanins and low amounts of all the other phenolic types in its red-colored flesh. The anthocyanin composition of Violeta grape was dominated by anthocyanidin 3,5-diglucosides (90%). Within flavonols, myricetin-type predominated and kaempferol-type was missing. In addition to expected hydroxycinnamoyl-tartaric acids, several isomeric esters of caffeic and p-coumaric acids with hexoses were tentatively identified, accounting for relevant proportions within the pool of HCAD. Although pending of further confirmation over successive vintages, the aforementioned results suggest that BRS Violeta grape cultivar could be considered an interesting candidate for the elaboration of highly colored and antioxidant-rich grape juices and wines. © 2013 Elsevier Ltd.

Structural and optical properties of brominated plasma polymers

Novel brominated amorphous hydrogenated carbon (a-C:H:Br) films were produced by the plasma polymerization of acetylene-bromoform mixtures. The main parameter of interest was the degree of bromination, which depends on the partial pressure of bromoform in the plasma feed, expressed as a percentage of the total pressure, R-B. When bromoform is present in the feed, deposition rates of up to about 110 nm min(-1) may be obtained. The structure and composition of the films were characterized by Transmission Infrared Reflection Absorption Spectroscopy (IRRAS) and X-ray Photo-electron Spectroscopy (XPS). The latter revealed that films with atomic ratios Br:C of up to 0.58 may be produced. Surface contact angles, measured using goniometry, could be increased from similar to 63 degrees (for an unbrominated film) to similar to 90 degrees for R-B of 60 to 80%. Film surface roughness, measured using a profilometer, does not depend strongly on R-B. Optical properties the refractive index, n, absorption coefficient, alpha(E), where E is the photon energy, and the optical gap, E-g, were determined from film thicknesses and data obtained by Transmission Ultraviolet-Visible Near Infrared Spectroscopy (UVS). Control of n was possible via selection of R-B. The measured optical gap increases with increasing F-BC, the atomic ratio of Br to C in the film, and semi-empirical modeling accounts for this tendency. A typical hardness of the brominated films, determined via nano-indentation, was similar to 0.5 GPa. (C), 2013 Elsevier B.V. All rights reserved.

Aging of red wines made from hybrid grape cv. BRS Violeta: Effects of accelerated aging conditions on phenolic composition, color and antioxidant activity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A comprehensive study on the phenolic profile of widely used culinary herbs and spices: Rosemary, thyme, oregano, cinnamon, cumin and bay

Herbs and spices have long been used to improve the flavour of food without being considered as nutritionally significant ingredients. However, the bioactive phenolic content of these plant-based products is currently attracting interest.In the present work, liquid chromatography coupled to high-resolution/accurate mass measurement LTQ-Orbitrap mass spectrometry was applied for the comprehensive identification of phenolic constituents of six of the most widely used culinary herbs (rosemary, thyme, oregano and bay) and spices (cinnamon and cumin). In this way, up to 52 compounds were identified in these culinary ingredients, some of them, as far as we know, for the first time. In order to establish the phenolic profiles of the different herbs and spices, accurate quantification of the major phenolics was performed by multiple reaction monitoring in a triple quadrupole mass spectrometer. Multivariate statistical treatment of the results allowed the assessment of distinctive features among the studied herbs and spices. (C) 2014 Elsevier Ltd. All rights reserved.

Home Cooking and Phenolics: Effect of Thermal Treatment and Addition of Extra Virgin Olive Oil on the Phenolic Profile of Tomato Sauces

Tomato products are a key component of the Mediterranean diet, which is strongly related to a reduced risk of cardiovascular events. The effect of cooking time (15, 30, 45, and 60 min) and the addition of extra virgin olive oil (5 and 10%) on the phenolic content of tomato sauces was monitored using liquid chromatography coupled to tandem mass spectrometry. Concentration of phenolics in the tomato sauces decreased during the cooking process, with the exception of caffeic acid and tyrosol. The main degradation observed was the oxidation of quercetin, since the hydroxy-function at the C-ring of this flavonoid is not blocked by a sugar moiety, unlike rutin. Higher levels of virgin olive oil in tomato sauce seemed to enhance the extraction of phenolic compounds from the tomato, leading to higher phenolic contents in the sauces. Thus, the food matrix containing the phenolic compounds plays a crucial role in determining their accessibility.

Phenolic compounds and antioxidant, antimicrobial and antimycobacterial activities of Serjania erecta Radlk. (Sapindaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Viscoelastic Behavior of Multiwalled Carbon Nanotubes into Phenolic Resin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of the length of alkyl side chains in the electronic structure of conjugated polymers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suitability of carbon fiber-reinforced polymers as power cable cores: Galvanic corrosion and thermal stability evaluation

The increasing demand for electrical energy and the difficulties involved in installing new transmission lines presents a global challenge. Transmission line cables need to conduct more current, which creates the problem of excessive cable sag and limits the distance between towers. Therefore, it is necessary to develop new cables that have low thermal expansion coefficients, low densities, and high resistance to mechanical stress and corrosion. Continuous fiber-reinforced polymers are now widely used in many industries, including electrical utilities, and provide properties that are superior to those of traditional ACSR (aluminum conductor steel reinforced) cables. Although composite core cables show good performance in terms of corrosion, the contact of carbon fibers with aluminum promotes galvanic corrosion, which compromises mechanical performance. In this work, three different fiber coatings were tested (phenol formaldehyde resin, epoxy-based resin, and epoxy resin with polyester braiding), with measurements of the galvanic current. The use of epoxy resin combined with polyester braiding provided the best inhibition of galvanic corrosion. Investigation of thermal stability revealed that use of phenol formaldehyde resin resulted in a higher glass transition temperature. On the other hand, a post-cure process applied to epoxy-based resin enabled it to achieve glass transition temperatures of up to 200 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.

Effect of Beverages and Mouthwashes on the Hardness of Polymers Used in Intraoral Prostheses

PurposeThe mechanical properties of acrylic resins used in intraoral prostheses may be altered by frequent exposure to liquids such as beverages and mouthwashes. This study aimed to evaluate the effect of thermocycling and liquid immersion on the hardness of four brands of acrylic resins commonly used in removable prostheses (Onda Cryl, QC-20, Classico, Lucitone).Materials and MethodsFor each brand of resin, seven specimens were immersed in each of six solutions (coffee, cola, red wine, Plax-Colgate, Listerine [LI], Oral B), and seven more were placed in artificial saliva (control). The hardness was tested using a microhardness tester before and after 5000 thermocycles and after 1, 3, 24, 48, and 96 hours of immersion. The results were analyzed using three-way repeated-measures ANOVA and Tukey's test (p < 0.05).ResultsThe hardness of the resins decreased following thermocycling and immersion in the solutions. Specimens immersed in cola and wine exhibited significant decreases in hardness after immersion for 96 hours, although the greatest significant decrease in hardness occurred in specimens immersed in LI. However, according to American Dental Association specification 12, the Knoop hardness of acrylic resins for intraoral prostheses should not be below 15. Thus, the median values of superficial hardness observed in most of the acrylic resins in this study are considered clinically acceptable.ConclusionsThe microhardness of polymers used for intraoral prostheses decreases following thermocycling. Among specimens immersed in beverages, those immersed in cola or wine experienced the greatest decrease in microhardness. Immersion of acrylic resins in LI significantly decreased the microhardness in relation to the initial value. Among the resins assessed, QC-20 exhibited the lowest initial hardness.

Evaluation of solvent effect on the extraction of phenolic compounds and antioxidant capacities from the berries: application of principal component analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparison of polymers and ceramics in new and discarded electrical insulators: reuse and recycling possibilities

The expansion and maintenance of electricity distribution networks generates large amounts of waste, much of it in the form of discarded insulators that are not reused or recycled. This paper describes the results of tests on used and new ceramic and polymeric insulators to verify if their exposure to weathering justifies their replacement. In new and used ceramic insulators, properties such as contact angle, relative density, porosimetry, dilatometry and X-ray diffraction patterns showed no differences or the differences that were found could not be related to their use. The discarded ceramic material showed high thermal stability, an interesting characteristic for application as chamotte. It can also be reused to replace gravel used in substations. In polymeric insulators, thermogravimetry, differential scanning calorimetry and relative density test results suggest degradation of used material compared to new. This would justify their replacement and discard as waste, but they show little recycling potential.

Phenolic compounds, carotenoids, tocopherols and fatty acids present in oils extracted from palm fruits

This review aimed to discuss the main bioactive compounds present in oils extracted from palm trees, indicating possible applications for the same. The bioactive compounds approached were: phenolic compounds, carotenoids, tocopherols, mono and polyunsaturated fatty acids. It is growing the search for food, especially from plant origin, characterized by the presence of such substances due to their benefi ts. Many studies show palm species as important sources of bioactive compounds and essential fatty acids. Therefore it is important to study the fruit characterization and composition of the oil from palm species of different regions that are still poorly investigated, seeking the possibility of its application in industry or the development of functional foods.

A new biomimetic sensor based on molecularly imprinted polymers for highly sensitive and selective determination of hexazinone herbicide

A new selective sensor based on molecularly imprinted polymers (MIPs) was developed for the determination of hexazinone (HXZ) in environmental samples. MIPs were synthesized using a non-covalent approach, and selection of the monomers employed in the polymerization reaction was carried out by molecular modeling. Three functional monomers with high (2-vinylpyridine (MP17)) and intermediate (methacrylic acid (MP12) and acrylamide (MP5)) energies of binding to the template (HXZ) were selected for preparation of the MIPs, in order to conduct comparative studies and validate the theoretical data. For sensor construction, carbon pastes were modified with each MIP or NIP (non-imprinted polymer), and HXZ determination was performed using differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV). All parameters affecting the sensor response were optimized. In HCl at pH 2.5, the sensor prepared with MP17 (5% w/w in the paste) showed a dynamic linear range between 1.9 × 10−11 and 1.1 × 10−10 mol L−1, and a detection limit of 2.6 × 10−12 mol L−1, under the following conditions: accumulation time of 200 s at a potential of −0.5V, scan rate of 50 mVs−1, pulse amplitude of 60 mV, and pulse width of 50 ms. The sensor was selective in the presence of other similar compounds, and was successfully applied to the analysis of HXZ in river water samples.