Phenolic composition and antioxidant activity of agroindustrial residues

Atualmente, são produzidas milhões de toneladas de resíduos provenientes do processamento agroindustrial. Muitos deles são ricos em compostos bioativos sendo potenciais fontes naturais dessas substâncias. Assim, este trabalho teve como objetivo avaliar o teor de compostos fenólicos totais, a atividade antioxidante e a composição fenólica de três resíduos gerados por agroindústrias brasileiras: bagaço de uva Isabel (BI) (Vitis labrusca), bagaço de uva Verdejo (BV) (Vitis vinifera) e bagaço de goiaba (BG) (Psidium guajava). Os resultados do teor de compostos fenólicos totais (mg GAE g-1) encontrados nos extratos etanólicos e aquosos dos resíduos foram, respectivamente: BV (20,94±0,46; 8,03±0,43)> BI (16,57±0,19; 4,41±0,01)> BG (3,41±0,09; 1,88±0,06). Alta atividade antioxidante, principalmente em BV e BI, foi verificada nos ensaios realizados (ABTS ●, DPPH ● e auto-oxidação do sistema beta-caroteno/ácido linoléico). Uma forte correlação positiva entre atividade antioxidante e o teor de compostos fenólicos totais foi encontrada. Os compostos fenólicos encontrados, por cromatografia gasosa com espectrometria de massas (CG-EM), foram: ácido gálico, epicatequina, quercetina (BV, BI e BG); ácido isovanílico (BI, BG); ácido p-cumárico (BI); ácido caféico e resveratrol (BV, BI). Esses resultados mostram que os resíduos agroindustriais analisados, particularmente os vinícolas, são ricos em substâncias bioativas e podem ser explorados pela indústria de alimentos e farmacêutica.Nowadays, the agro-industrial processing produces millions of tons of wastes. Many of them are rich in bioactive compounds, being a potential natural source of these substances. This study aimed to evaluate the content of total phenolics, antioxidant activity and phenolic composition of residues generated by three Brazilian agribusiness: Isabel grape pomace (PI) (Vitis labrusca), Verdejo grape pomace (PV) (Vitis vinifera) and guava pomace (PG) (Psidium guajava). The results of total phenolics content (mg GAE g-1) found in the ethanol and aqueous extracts of residues were: PV (20.94±0.46; 8.03±0.43)>PI (16.57±0.19; 4.41±0.01)>PG (3.41±0.09; 1.88±0.06). High antioxidant activity of these extracts, particularly PV and PI, was found by the methods DPPH ●, ABTS ● and beta-carotene bleaching method. A strong positive correlation between antioxidant activity and content of total phenolic compounds was found. The following phenolic compounds were found by gas chromatography with mass spectrometry (GC-MS): gallic acid, epicatechin, quercetin (PV, PI and PG); isovanilic acid (PI, PG), p-coumaric acid (PI), caffeic acid and resveratrol (PV, PI). The results show that these residues, particularly the wineries, are rich in bioactive substances and should be exploited by the food industry and pharmaceuticals

Physicochemical characterization of must and wine Moscato Giallo from grapevines grown under plastic overhead cover

O objetivo deste trabalho foi avaliar a influência da cobertura de plástico sobre as características físico-químicas do mosto e do vinho da cultivar Moscato Giallo. Na safra 2006, um experimento em delineamento completamente casualizado foi realizado em vinhedo com cobertura de plástico impermeável, e sem cobertura como controle. De cada vinhedo, três microvinificações (20 L) foram elaboradas. Foram realizadas avaliações físico-químicas quanto ao: mosto – oBrix, açúcares redutores, densidade, acidez total, ácido tartárico, ácido málico e pH; e vinho – densidade, graduação alcoólica, acidez total, acidez volátil, pH, extrato seco, açúcares redutores, cinzas, I 420, compostos voláteis e minerais. O mosto das videiras cobertas apresentou maior rendimento, porém, menor concentração de açúcares pelo fato de a maturação das uvas ter-se atrasado. Como conseqüência, os vinhos do cultivo protegido tiveram menor graduação alcoólica, embora tenham sido beneficiados pela sanidade das uvas, com a redução de acetato de etila e acidez volátil. O microclima da cobertura também restringiu a concentração de alguns minerais no vinho, principalmente P e K. A cobertura beneficiou a qualidade enológica, porém requer atraso na data de colheita, para as uvas atingirem adequada maturação fisiológica e tecnológica.The objective of this work was to evaluate the plastic overhead cover (POC) effect on must and wine composition of the cultivar Moscato Giallo. In 2006 vintage, it was performed a completely randomly designed experiment, in a vineyard covered with an impermeable plastic cloth, and without covering as control. From each vineyard, three microvinification (20 L) were elaborated. Physico-chemical analysis were performed for: musts – oBrix, reducer sugar contents, density, total acidity, tartaric acid, malic acid and pH; and wines – density, alcohol degree, acidity, volatile acidity, pH, dry extract, reducer sugar contents, ashes, I 420, volatile compounds and minerals. The must of the covered vineyard presented higher yield, but lower sugar content, due to delay on ripening. As consequence, the POC wines showed lower alcohol degree, but with the benefit of a lower ethyl-acetate and volatile acidity levels. The POC microclimate also caused a decrease of some minerals (mainly P and K) in the wines. POC improved the enological quality, however, this demands delay in the harvest date to achieve the adequate physiological and technological maturation of grapes

Discrimination of Brazilian red wines according to the viticultural region, varietal, and winery origin

This work evaluated the physicochemical composition of 171 red Brazilian wines from the 2006 vintage, which were represented by 21 varietals. These wines were produced by 58 Brazilian wineries in different regions of the country, with latitudes varying from 9º to 31º South. Physicochemical wine analysis was performed in the same year and discrimination in the viticultural regions, varietal wines, and wineries was performed by means of the principal component analysis (PCA). The main results show that wines from São Joaquim had higher values of A420, A520, A620, color intensity, total phenolic compounds, anthocyanins, and dry extracts, while those from Toledo had lower values of these variables; those from Vale do São Francisco had higher values of potassium, pH, density, and volatile acidity; from Serra do Nordeste A, they had higher titratable acidity; and from Planalto Superior B, higher hue. Regarding the varietal wines, PCA mainly discriminated the wines produced from the varieties Ancellotta, Teroldego, Egiodola, Refosco, Marselan, Cabernet Sauvignon, Pinotage, Pinot Noir, Malbec, Arinarnoa, Barbera, and Alfrocheiro. In relation to wineries, twenty two of them were discriminated by their higher values of some variables, i.e., three were characterized by color intensity; three by hue; eight by alcohol content; six by potassium, dry extract, density, and pH; and two by titratablel acidity

Volatile characterization by multivariate optimization of headspace-solid phase microextraction and sensorial evaluation of chardonnay base wines

Pouco é conhecido sobre o aroma dos vinhos produzidos na região sul do Brasil, que é responsável por 90% da produção brasileira de vinho. Um método baseado na microextração em fase sólida no modo “headspace” (HS-SPME) foi desenvolvido para a extração de compostos voláteis e semivoláteis relacionados ao aroma de vinhos base, de cinco diferentes vinícolas do estado do Rio Grande do Sul (Brasil). A relação entre a composição volátil, qualidade aromática e avaliação sensorial dos vinhos Chardonnay foi investigada neste estudo. As condições otimizadas do método de HS-SPME foram: utilização da fibra DVB-CAR-PDMS, 1 mL de amostra, 30% de NaCl, 45 min de extração a 55 ºC, sem o uso de diluição e agitação da amostra. Dezoito compostos foram identificados e catorze foram tentativamente identificados. Os ésteres foram os compostos majoritários (56%) e os outros compostos minoritários pertencem à classe dos álcoois e ácidos. Os vinhos do Vale dos Vinhedos e de Pinto Bandeira apresentaram a mais alta pontuação em relação aos parâmetros sensorais avaliados. Estes vinhos foram caracterizados por altas concentrações de ésteres etílicos, o que contribui para o aroma frutado dos vinhos.Very little is known about the aroma of wines produced in the South part of Brazil, a region that is responsible for 90% of the Brazilian wine production. A headspace solid phase micro extraction (HS-SPME) method was developed for the extraction of volatile and semivolatile compounds related to the aroma of base wines of five different wineries of the state of Rio Grande do Sul (Brazil). The relationships among volatile composition, aroma quality and sensory evaluation of Chardonnay base wines were performed in this study. Optimum conditions for HS-SPME included use of DVB-CAR-PDMS coating, wine samples without further dilution, no stirring, sample volume of 1 mL, 30% of NaCl, extraction time and temperature of 45 min and 55 ºC, respectively. Eighteen compounds were identified and fourteen were tentatively identified in the samples. The majority (56%) of them was esters and other minor components were alcohols and acids. The sensory analysis of Vale dos Vinhedos and Pinto Bandeira samples showed the highest quality scores, characterized by higher concentrations of ethyl esters, which contributes to the fruity aroma of these wines

Criteria used in the specifications for geographical indications of fine wines in Brazil / Critères utilisés dans les cahiers des charges des indications géographiques des vins fins au Brésil

The Brazilian legislation on geographical indications (GI) are the Law 9.279 and INPI Normative Instruction 25/2013, establishing the conditions for the registration of GI, whether in modality of “Indicação de Procedência” (IP) or “Denominação de Origem” (DO). Brazil has recognized some GI of fine wines - IP Vale dos Vinhedos, Pinto Bandeira, Altos Montes, Monte Belo and Farroupilha, and DO Vale dos Vinhedos. Others are in structuring process - Campanha Gaúcha, Vale do São Francisco and Altos de Pinto Bandeira. Even without detailing, by INPI, the elements that must be in the specification document, the GI already recognized include, among others: delimited geographical area; varieties of Vitis vinifera authorized; grape production in the delimited area; training systems; maximum productivity; quality of grapes for wine making; authorized wines; oenological practices; physicochemical characteristics for each type of wine and mandatory sensory analysis; elaboration, aging and bottling in the delimited area; labeling standards. In addition, for each GI there is a specific plan of control. It is possible to observe that the specifications for Brazilian GI of wines have some similarity to those adopted in the European Community, and are more specific and demanding than most of the existing GI in the New World

Volatile characterization by multivariate optimization of headspace-solid phase microextraction and sensorial evaluation of chardonnay base wines

Pouco é conhecido sobre o aroma dos vinhos produzidos na região sul do Brasil, que é responsável por 90% da produção brasileira de vinho. Um método baseado na microextração em fase sólida no modo “headspace” (HS-SPME) foi desenvolvido para a extração de compostos voláteis e semivoláteis relacionados ao aroma de vinhos base, de cinco diferentes vinícolas do estado do Rio Grande do Sul (Brasil). A relação entre a composição volátil, qualidade aromática e avaliação sensorial dos vinhos Chardonnay foi investigada neste estudo. As condições otimizadas do método de HS-SPME foram: utilização da fibra DVB-CAR-PDMS, 1 mL de amostra, 30% de NaCl, 45 min de extração a 55 ºC, sem o uso de diluição e agitação da amostra. Dezoito compostos foram identificados e catorze foram tentativamente identificados. Os ésteres foram os compostos majoritários (56%) e os outros compostos minoritários pertencem à classe dos álcoois e ácidos. Os vinhos do Vale dos Vinhedos e de Pinto Bandeira apresentaram a mais alta pontuação em relação aos parâmetros sensorais avaliados. Estes vinhos foram caracterizados por altas concentrações de ésteres etílicos, o que contribui para o aroma frutado dos vinhos.Very little is known about the aroma of wines produced in the South part of Brazil, a region that is responsible for 90% of the Brazilian wine production. A headspace solid phase micro extraction (HS-SPME) method was developed for the extraction of volatile and semivolatile compounds related to the aroma of base wines of five different wineries of the state of Rio Grande do Sul (Brazil). The relationships among volatile composition, aroma quality and sensory evaluation of Chardonnay base wines were performed in this study. Optimum conditions for HS-SPME included use of DVB-CAR-PDMS coating, wine samples without further dilution, no stirring, sample volume of 1 mL, 30% of NaCl, extraction time and temperature of 45 min and 55 ºC, respectively. Eighteen compounds were identified and fourteen were tentatively identified in the samples. The majority (56%) of them was esters and other minor components were alcohols and acids. The sensory analysis of Vale dos Vinhedos and Pinto Bandeira samples showed the highest quality scores, characterized by higher concentrations of ethyl esters, which contributes to the fruity aroma of these wines