Colour, phenolic content and antioxidant activity of grape juice

Viticultural practices in the State of Santa Catarina, Brazil, have shown economic growth, with the production of grapes used to produce wines and grape juice. Grapes are rich in phenolic compounds which have drawn attention not only because of their important role in the development of products derived from grapes, but also for their potential beneficial health effects. The objective of this study was to evaluate commercial, organic and homemade grape juices produced in Santa Catarina. Grape juices were analyzed for total phenolic content, colour, and antioxidant activity. The commercial juices had the highest average values for total monomeric anthocyanins and total phenolics. There was a strong positive correlation (R = 0.9566) between the antioxidant activity and total phenolic content for the commercial juice. In addition, the Principle Components Analysis showed a strong positive correlation between the red colour and total monomeric anthocyanins. However, the total monomeric anthocyanis and polymeric anthocyanins showed a negative correlation.

Quinoa (Chenopodium quinoa, Willd.) as a source of dietary fiber and other functional components

Four varieties of an Andean indigenous crop, quinoa (Chenopodium quinoa Willd.), were evaluated as a source of dietary fiber, phenolic compounds and antioxidant activity. The crops were processed by extrusion-cooking and the final products were analyzed to determine the dietary fiber, total polyphenols, radical scavenging activity, and in vitro digestibility of starch and protein. There were no significant differences in the contents of total dietary fiber between varieties of quinoa. In all cases, the contents of total and insoluble dietary fiber decreased during the extrusion process. At the same time, the content of soluble dietary fiber increased. The content of total phenolic compounds and the radical scavenging activity increased during the extrusion process in the case of all 4 varieties. There were significant differences between the varieties and the content of total polyphenols. The in vitro protein digestibility of quinoa varieties was between 76.3 and 80.5% and the in vitro starch digestibility was between 65.1 and 68.7%. Our study demonstrates that quinoa can be considered a good source of dietary fiber, polyphenols and other antioxidant compounds and that extrusion improves the nutritional value.

Evaluation of phenolic compounds content and in vitro antioxidant activity of red wines produced from Vitis labrusca grapes

Wine production in the northern Curitiba, Paraná, Brazil, specifically the communes of Colombo and Almirante Tamandaré, is based mainly on the utilization of Vitis labrusca grapes var. Bordô (Ives). Total sugar content, pH, and total acidity were analyzed in red wine samples from 2007 and 2008 vintages following official methods of analysis. Moreover, total phenolic, flavonoid, and tannin contents were analyzed by colorimetric methodologies and the antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical methodology. Phenolic compounds were identified by high performance liquid chromatography. The total phenolic content of wine samples presented concentrations varying between 1582.35 and 2896.08 mg gallic acid.L-1 since the major part corresponds to flavonoid content. In these compounds' concentration range, a direct relationship between phenolic compounds content and levels of antioxidant activity was not observed. Among the identified phenolic compounds, chlorogenic, caffeic, and syringic acids were found to be the major components. Using three principal components, it was possible to explain 81.36% of total variance of the studied samples. Principal Components Analysis does not differentiate between vintages.

Phenolic compounds and antioxidant activity of hydroalcoholic extracts of wild and cultivated murtilla (Ugni molinae Turcz.)

Over the last decade a considerable increase in the number of studies addressing the use of antioxidants from natural sources has led to the identification and understanding of the potential mechanisms of biologically active components. This results from the fact that they can be used to replace synthetic antioxidants commonly used in food. Murtilla (Ugni molinae Turcz) is a native berry grown in Chile, and in the present study, the phenolic composition and antioxidant activity of its fruits were studied. Hydroalcoholic extracts of dehydrated fruits from two genotypes of murtilla (Ugni molinae Turcz.) were produced. Extracts of wild murtilla and 14-4 genotype fruits had 19.35 and 40.28mg GAE/g for Total Phenolic Compounds, 76.48, and 134.35μmol TEAC/g for DPPH, and 157.04 and 293.99 μmol TEAC/g for ABTS, respectively. Components such as quercetin, epicatechin, and gallic, benzoic and hydrocaffeic acids were identified by CG/MS analysis. All of them showed antioxidant activity. Therefore, it is possible to say that the hydroalcoholic extracts of murtilla have antioxidant potential to be used in lipidic food.

Elucidation of the components involved in the antioxidant activity of honey

Canadian honeys were analyzed for sugar concentration, honey colour, total phenolic content, the level of brown pigments, and antioxidant activity in order to elucidate the main components involved in the antioxidant activity of honey. By employing size-exclusion chromatography in combination with activity-guided fractionation, it was demonstrated that the antioxidant components are of high molecular weight (HMW), brown in colour and absorb at both 280nm and 450nm. The presence of brown HMW antioxidant components prompted an investigation on the influence of heattreatment on the Maillard reaction and the formation of melanoid ins. Heat-treatment of honey resulted in an increase in the level of phenolics in the melanoidin fractions which correlated with an increase in antioxidant activity. The preliminary results of this study suggest for the first time that honey melanoidins underlie the antioxidant activity of unheated and heat-treated honey, and that phenolic constituents are involved in the melanoidin structure and are likely incorporated by covalent or non-covalent interaction.

Effects of enrichment of refined olive oil with phenolic compounds from olive leaves

The possibility of preparing olive oil, with the same nutritional value and stability characteristics found in virgin olive oil, by the enrichment of refined olive oil with olive leaf polyphenols was studied. To obtain antioxidant phenols similar to those found in virgin olive oil, these components were extracted from the leaves of several olive cultivars from the Northern region of Portugal, namely, Carrasca, Ripa, Negruche, Cordovil, Verdeal, Madural, and Bical cultivars, under several conditions. The concentration of a leaf extract required for addition to refined olive oil to obtain the same stability as virgin olive oil was determined. The extract from 1 kg of leaves was sufficient to fortify 50-320 L of refined olive oil to a similar stability as a virgin olive oil sample depending on the metal concentration of the oil, cultivar, and time of the year when the leaves were picked.

Changes in phenolic composition and antioxidant activity of virgin olive oil during frying

The concentration of hydroxytyrosol (3,4-DHPEA) and its secoiridoid derivatives (3,4-DHPEA-EDA and 3,4-DHPEA-EA) in virgin olive oil decreased rapidly when the oil was repeatedly used for preparing french fries in deep-fat frying operations. At the end of the first frying process (10 min at 180 degreesC), the concentration of the dihydroxyphenol components was reduced to 50-60% of the original value, and after six frying operations only about 10% of the initial components remained. However, tyrosol (p-HPEA) and its derivatives (p-HPEA-EDA and p-HPEA-EA) in the oil were much more stable during 12 frying operations. The reduction in their original concentration was much smaller than that for hydroxytyrosol and its derivatives and showed a roughly linear relationship with the number of frying operations. The antioxidant activity of the phenolic extract measured using the DPPH test rapidly diminished during the first six frying processes, from a total antioxidant activity higher than 740,mumol of Trolox/kg down to less than 250 mumol/kg. On the other hand, the concentration of polar compounds, oxidized triacylglycerol monomers (oxTGs), dimeric TGs, and polymerized TGs rapidly increased from the sixth frying operation onward, when the antioxidant activity of the phenolic extract was very low, and as a consequence the oil was much more susceptible to oxidation. The loss of antioxidant activity in the phenolic fraction due to deep-fat frying was confirmed by the storage oil and oil-in-water emulsions containing added extracts from olive oil used for 12 frying operations.

Evaluation by volatile profile of the synergistic antioxidant effect between bovine serum albumin and virgin olive oil phenolic compounds in an oil-in-water emulsion

THE OXIDATIVE STABILITY OF OIL-IN-WATER EMULSIONS, CONTAINING BOVINE SERUM ALBUMIN (BSA) AND VIRGIN OLIVE OIL PHENOLIC COMPOUNDS, WAS STUDIED BY THE DETERMINATION OF THE FORMATION OF VOLATILE OXIDATION PRODUCTS. FOUR OIL-IN-WATER EMULSIONS WITH AND WITHOUT PHENOLS ISOLATED FROM VIRGIN OLIVE OIL AND BSA WERE PREPARED. THESE MODEL SYSTEMS WERE STORED AT 60 degrees C TO ACCELERATE LIPID OXIDATION. VOLATILE OXIDATION PRODUCTS WERE MONITORED EVERY THREE DAYS BY HEADSPACE SOLID-PHASE MICROEXTRACTION COUPLED WITH GAS CHROMATOGRAPHY. ALTHOUGH INDIVIDUALLY OLIVE OIL PHENOLIC COMPOUNDS AND BSA SHOWED A SIGNIFICANT ANTIOXIDANT ACTIVITY, THE COMBINATION OF THESE COMPONENTS SHOWED A VERY GOOD SYNERGY, QUANTIFIED AS 127%. IN FACT, THE EMULSION CONTAINING BOTH PHENOLIC COMPOUNDS AND BSA SHOWED A VERY LOW LEVEL OF OXIDATIVE DETERIORATION AFTER 45 DAYS STORAGE.

Components of olive oil and chemoprevention of colorectal cancer

Olive oil contains a vast range of substances such as monounsaturated free fatty acids (e.g., oleic acid), hydrocarbon squalene, tocopherols, aroma components, and phenolic compounds. Higher consumption of olive oil is considered the hallmark of the traditional Mediterranean diet, which has been associated with low incidence and prevalence of cancer, including colorectal cancer. The anticancer properties of olive oil have been attributed to its high levels of monounsaturated fatty acids, squalene, tocopherols, and phenolic compounds. Nevertheless, there is a growing interest in studying the role of olive oil phenolics in carcinogenesis. This review aims to provide an overview of the relationship between olive oil phenolics and colorectal cancer, in particular summarizing the epidemiologic, in vitro, cellular, and animal studies on antioxidant and anticarcinogenic effects of olive oil phenolics.

Phenolic acid intake, delivered via moderate champagne wine consumption, improves spatial working memory via the modulation of hippocampal and cortical protein expression/activation.

Aims: While much data exist for the effects of flavonoid-rich foods on spatial memory in rodents, there are no such data for foods/beverages predominantly containing hydroxycinnamates and phenolic acids. To address this, we investigated the effects of moderate Champagne wine intake, which is rich in these components, on spatial memory and related mechanisms relative to the alcohol- and energy-matched controls. Results: In contrast to the isocaloric and alcohol-matched controls, supplementation with Champagne wine (1.78 ml/kg BW, alcohol 12.5% vol.) for 6 weeks led to an improvement in spatial working memory in aged rodents. Targeted protein arrays indicated that these behavioral effects were paralleled by the differential expression of a number of hippocampal and cortical proteins (relative to the isocaloric control group), including those involved in signal transduction, neuroplasticity, apoptosis, and cell cycle regulation. Western immunoblotting confirmed the differential modulation of brain-derived neurotrophic factor, cAMP response-element-binding protein (CREB), p38, dystrophin, 2',3'-cyclic-nucleotide 3'-phosphodiesterase, mammalian target of rapamycin (mTOR), and Bcl-xL in response to Champagne supplementation compared to the control drink, and the modulation of mTOR, Bcl-xL, and CREB in response to alcohol supplementation. Innovation: Our data suggest that smaller phenolics such as gallic acid, protocatechuic acid, tyrosol, caftaric acid, and caffeic acid, in addition to flavonoids, are capable of exerting improvements in spatial memory via the modulation in hippocampal signaling and protein expression. Conclusion: Changes in spatial working memory induced by the Champagne supplementation are linked to the effects of absorbed phenolics on cytoskeletal proteins, neurotrophin expression, and the effects of alcohol on the regulation of apoptotic events in the hippocampus and cortex. Antioxid. Redox Signal. 00, 000-000.

Tracking (poly)phenol components from raspberries in ileal fluid

The (poly)phenols in ileal fluid after ingestion of raspberries were analysed by targeted and non-targeted LC-MSn approaches. Targeted approaches identified major anthocyanin and ellagitannin components at varying recoveries and with considerable inter-individual variation. Non-targeted LC-MSn analysis using an Orbitrap mass spectrometer gave exact mass MS data which was sifted using a software program to select peaks that changed significantly after supplementation. This method confirmed the recovery of the targeted components but also identified novel raspberry-specific metabolites. Some components (including ellagitannin and previously unidentified proanthocyanidin derivatives) may have arisen from raspberry seeds that survived intact in ileal samples. Other components include potential breakdown products of anthocyanins, unidentified components and phenolic metabolites formed in either the gut epithelia or after absorption into the circulatory system and efflux back into the gut lumen. The possible physiological roles of the ileal metabolites in the large bowel are discussed.

Extracts from pitanga (Eugenia uniflora L.) leaves: Influence of extraction process on antioxidant properties and yield of phenolic compounds

Different extraction processes were employed to extract the polyphenolic compounds from pitanga (Eugenia uniflora L) leaves: a one-step process using water, ethanol or supercritical CO(2) as solvents, and a two-step process using supercritical CO(2) followed by either water or ethanol. The total polyphenolic compounds, total flavonoids and antioxidant activity were determined in all the extracts obtained. The process performance was evaluated with respect to three variables: global extraction yield, concentration and yield of both polyphenols and flavonoids in the extracts. For the one-step extraction, the results showed that the extraction yield increased with solvent polarity. For the two-step process, the results suggested that water was more efficient in extracting the phenolic compounds from E. uniflora when the matrix was previously extracted with scCO(2). With respect to the antioxidant activity, the ethanolic extracts obtained from both processes, using either the DPPH radical scavenging method or the beta-carotene bleaching method, presented high antioxidant activities. (C) 2010 Elsevier B.V. All rights reserved.

Coumarins and phenolic fingerprints of oak and Brazilian woods extracted by sugarcane spirit

A total of 25 sugarcane spirit extracts of six different Brazilian woods and oak, commonly used by cooperage industries for aging cachaca, were analyzed for the presence of 14 phenolic compounds (ellagic acid, gallic acid, vanillin, syringaldehyde, synapaldehyde, coniferaldehyde, vanillic acid, syringic acid, quercetin, trans-resveratrol, catechin, epicatechin, eugenol, and myricetin) and two coumarins (scopoletin and coumarin) by HPLC-DAD-fluorescence and HPLC-ESI-MS(n). Furthermore, an HPLC-DAD chromatographic fingerprint was build-up using chemometric analysis based on the chromatographic elution profiles of the extracts monitored at 280 nm. Major components identified and quantified in Brazilian wood extracts were coumarin, ellagic acid, and catechin, whereas oak extracts shown a major contribution of catechin, vanillic acid, and syringaldehyde. The main difference observed among oak and Brazilian woods remains in the concentration of coumarin, catechin, syringaldehyde, and coniferaldehyde. The chemometric analysis of the quantitative profile of the 14 phenolic compounds and two coumarins in the wood extracts provides a differentiation between the Brazilian wood and oak extracts. The chromatographic fingerprint treated by multivariate analysis revealed significant differences among Brazilian woods themselves and oak, clearly defining six groups of wood extracts: (i) oak extracts, (ii) jatoba extracts, (iii) cabreuva-parda extracts, (iv) amendoim extracts, (v) canela-sassafras extracts and (vi) pequi extracts.

Evaluation of Antioxidant Capacity and Synergistic Associations of Quinonemethide Triterpenes and Phenolic Substances from Maytenus ilicifolia (Celastraceae)

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

Use of a cashew nut shell liquid resin as a potential replacement for phenolic resins in the preparation of panels - a review

The Cashew Nut Shell Liquid (CNSL) can be considered as a versatile raw material with wide applications in the form of surface coatings, paints and varnishes, as well as the production of polymers. Within this context, the chemical constituents of CNSL (anarcadic acid, cardanol, 2-cardol and methylcardol) become promising in the development of new materials components. Once separated, CNSL can be used in the research and development of additives, surfactants, pharmaceuticals, pesticides, polymers, resins and others. Being a byproduct, CNSL used in the preparation of new materials is characterized as a truly technological innovation.