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Metabolic fate of dietary volatile compounds in Pieris brassicae

Fernandes, F.; Pereira, D.M.; Pinho, P. Guedes de; Valentão, P.; Pereira, J.A.; Bento, Albino; Andrade, P.B.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.5%
In this work, the evolution of the qualitative and quantitative profile of the volatile fraction of Pieris brassicae after feeding on Brassica oleracea var. acephala (kale) was monitored through time. HS-SPME/GC-MS was applied to both the host plant and the living insect and its excrements. A total of seventy seven compounds (lipoxygenase pathway by-products, nitrogen compounds, norisoprenoids, sulphur compounds, terpenes, among others) were identified. Thirty eight compounds were identified in insect after 2 h of starvation and forty eight compounds in excrements. Qualitative and quantitative changes were detected along time. Dimethyldisulfide, dimethyltrisulfide, limonene and eugenol were major compounds for all analysed times in both matrices, being limonene an important compound in insect after starvation. The accumulation by P. brassicae of some compounds, such as limonene, was verified, suggesting a mechanism by which the insect can take benefit from bioactive constituents from the diet. Along with accumulation, complete excretion of some compounds, including nitrogen bearing compounds, by-products of glucosinolates was detected. These results reflect one of the strategies used to overcome plant barriers, namely detoxification of toxic compounds. The findings contribute to the knowledge of the metabolization of the volatile compounds in insects and contribute to the body of knowledge of this ecologic system.

Volatile compounds in the thermoplastic extrusion of bovine rumen

SILVA, Ana Carolina Conti e; BASTOS, Deborah Helena Markowicz; ARÊAS, José Alfredo Gomes; FACANALI, Roselaine; MARQUES, Marcia Ortiz M.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
66.45%
The volatile compounds of raw and extruded bovine rumen, extracted by dynamic headspace, were separated by gas chromatography and analyzed by GC-MS. Raw and extruded materials presented thirty-two volatile compounds. The following compounds were identified in raw bovine rumen: heptane, 1-heptene, 4-methyl-2-pentanone, toluene, hexanal, ethyl butyrate, o-xylene, m-xylene, p-xylene, heptanal, limonene, nonanal, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. The following compounds were identified in the extruded material: 1-heptene, 2,4-dimethylhexane, toluene, limonene, undecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane and nonadecane. Mass spectra of some unidentified compounds indicated the presence of hydrocarbons with branched chains or cyclic structure.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gases and volatile compounds associated with micro-organisms in blown pack spoilage of Brazilian vacuum-packed beef

Macedo, Maria Lucila Hernández; Castillo, Carmen Josefina Contreras; Mui, Tsai Siu; Cruz, Sandra Helena da; Sarantopoulos, C. I. G. L.; Padula, M.; Dias, Carlos Tadeu dos Santos
Fonte: WILEY-BLACKWELL; HOBOKEN Publicador: WILEY-BLACKWELL; HOBOKEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.48%
This study correlated the composition of the spoilage bacterial flora with the main gaseous and volatile organic compounds (VOCs) found in the package headspace of spoiled, chilled, vacuum-packed meat. Fifteen chilled, vacuum-packed beef samples, suffering from blown pack spoilage, were studied using 16S rRNA clone sequencing. More than 50% of the bacteria were identified as lactic acid bacteria (LAB), followed by clostridia and enterobacteria. Fifty-one volatile compounds were detected in the spoiled samples. Although the major spoilage compounds were identified as alcohols and aldehydes, CO2 was identified as the major gas in the spoiled samples by headspace technique. Different species of bacteria contribute to different volatile compounds during meat spoilage. LAB played an important role in blown pack deterioration of the Brazilian beef studied.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [CNPq 58223/2008-2, 578753-1]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [FAPESP 08/58622-9, 07/58815-9]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo

A influência da proximidade da biodiversidade da Mata Atlântica no perfil de compostos voláteis de bananas (Musa acuminata AAA cv. Nanicão) produzidas no Vale do Ribeira-SP; The influence of the proximity of the Atlantic Rainforest biodiversity in the profile of volatile compounds from bananas (Musa acuminate AAA cv. Nanicão) produced in Vale do Ribeira, SP

Calhau, Maria Fernanda Nobre dos Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/09/2014 PT
Relevância na Pesquisa
66.48%
O principal polo produtor de banana no estado de São Paulo está na Divisão Regional e Agrícola de Registro, que se estende do Vale do Ribeira até o litoral sul do estado. Nesta região, a produção de banana é a principal atividade dos produtores rurais e é responsável pela principal demanda de insumos e serviços de comercialização. No entanto, o Vale do Ribeira se caracteriza por ser uma região com baixos níveis de tecnologia e mecanização e a qualidade de vida é bastante baixa, fatores que contribuem para a baixa produtividade da banana. Este trabalho teve como objetivo estabelecer os efeitos que a proximidade da biodiversidade nativa da Mata Atlântica promove nos atributos físico-químicos e bioquímicos do fruto da bananeira, em decorrência da proximidade da biodiversidade. Duas parcelas foram escolhidas para fornecer as amostras posteriormente analisadas quanto a parâmetros fisiológicos, químicos e bioquímicos: a parcela "Controle" plenamente inserida em um bananal convencional e a parcela "Biodiversidade" com 60% de seu perímetro rodeado pela biodiversidade da Mata Atlântica. Foram feitas as seguintes avaliações nos frutos colhidos destas parcelas: análise dos perfis de etileno e CO2 endógenos por cromatografia gasosa...

Production of volatile compounds by Geotrichum fragrans using cassava wastewater as substrate

Damasceno, S.; Cereda, M. P.; Pastore, G. M.; Oliveira, J. G.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 411-414
ENG
Relevância na Pesquisa
66.51%
The cassava processing industry generates wastewater named manipueira with a high organic content. Although considered a pollutant, manipueira can be used as substrate for fermentative processes including the cultivation of Geotrichum fragrans. This aerobic microorganism isolated from cassava wastewater has cyanide resistant respiration. Under cassava wastewater cultivation, G. fragrans produced fruit aroma volatile compounds. This study evaluated volatile compounds produced by G. fragrans in cassava liquid waste. The waste had a sugar composition composed of dextrin (2.6%), maltose (1.4%), sucrose (32.1%), glucose (38.3%), and fructose (25.6%). The average value of total sugars was 58.2 g l(-1), composed of 38.0 g l(-1) reducing and 20.2 g l(-1) non-reducing sugars. The chemical oxygen demand (COD) average value was 60 000 mg l(-1). G. fragrans used sugars (fructose and glucose) for energy generation reducing the COD value of the cassava wastewater by 40%. Biomass production of G. fragrans cultivated for 12 h in natural cassava liquid waste was 12.8 g l(-)1. The volatile compounds identified in the cassava liquid waste after 72 h cultivation were: 1-butanol, 3-methyl 1-butanol (isoamylic alcohol), 2-methyl 1-butanol, 1-3 butanodiol and phenylethanol; ethyl acetate...

Compostos volateis e qualidade dos vinhos secos jovens varietal cabernet suavignon produzidos em diferentes regiões do Brasil.; Volatile compounds and quality of cabernet sauvignon wines from different regions of Brazil.

Betania Araujo Cosme dos Santos
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 22/02/2006 PT
Relevância na Pesquisa
66.63%
Apesar da importância do aroma e sabor para determinar a qualidade dos vinhos, praticamente não existe nenhum estudo sobre a composição de voláteis dos vinhos nacionais. Os poucos que existem utilizam ainda coluna empacotada e outros traçam apenas o perfil sensorial dos vinhos, sem fazer correlações dos dados com qualquer outro parâmetro. No presente trabalho estudou-se 11 vinhos seco varietal Cabernet Sauvignon oriundos das principais regiões produtoras do país: Serra Gaúcha e Campanha, no Rio Grande do Sul; do Vale do Rio do Peixe, em Santa Catarina e do Vale do São Francisco, região de Pernambuco/Bahia. Foram efetuadas análises dos constituintes químicos e minerais presentes, após a homogeneização de três garrafas de vinho. Os parâmetros físico-químicos foram determinados pelos métodos clássicos e os teores dos minerais cálcio, magnésio, ferro, cobre e zinco foram analisados por absorção atômica; potássio, lítio, sódio e rubídio por emissão de chama e o fósforo por colorimetria. As características sensoriais das amostras foram determinadas pelo uso da Análise Descritiva Quantitativa através de nove provadores selecionados e treinados. As amostras foram avaliadas em quintuplicata, em 11 sessões...

Compostos voláteis em vinhos Chardonnay (Vitis vinifera L.) produzidos em diferentes regiões brasileiras; Volatile compounds in Chardonnay (Vitis vinifera L.) wines produced in different regions of Brazil

Sabrina de Bona Sartor
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/02/2014 PT
Relevância na Pesquisa
66.6%
O aroma final de um vinho é formando por um grande número de compostos químicos voláteis, presentes em concentrações variáveis e detectáveis pelo sistema olfativo humano. O estudo da fração volátil de vinhos tem sido o objetivo de muitas iniciativas de estudo, sendo que as metodologias de pesquisa de compostos voláteis em vinhos compreendem etapas fundamentais, tais como: a extração dos compostos, a separação das diferentes moléculas por cromatografia gasosa acoplada à um sistema de detecção e posteriormente, a identificação e quantificação dos compostos voláteis. O objetivo deste trabalho foi extrair, identificar e quantificar os compostos voláteis de vinhos Chardonnay produzidos em diferentes regiões brasileiras utilizando microextração em fase sólida no modo de headspace (HS-SPME) e cromatografia gasosa acoplada à espectrometria de massas tandem (GC-MSMS). As amostras foram produzidas nas principais regiões vitícolas brasileiras: Serra Gaúcha e Campanha (Rio Grande do Sul), Serra Catarinense e Região de Altitude (Santa Catarina) e Sul de Minas (Minas Gerais). O método de extração de compostos de aroma foi desenvolvido usando a técnica de HS-SPME e GC-MS/MS e análise multivariada com delineamento composto central rotacional (CCRD) e metodologia de superfície de resposta para obtenção de um ponto ótimo de extração. As condições otimizadas foram temperatura (°C) e tempo (minutos) de extração. A otimização multivariada das condições de extração por HS-SPME permitiu avaliar os efeitos de tempo e temperatura de extração nesta metodologia...

Alcoholic beverage from cheese whey : identification of volatile compounds

Dragone, Giuliano; Mussatto, Solange I.; Oliveira, J. M.; Teixeira, J. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 06/04/2008 ENG
Relevância na Pesquisa
66.46%
A spirit was produced from cheese whey continuous fermentation by Kluyveromyces marxianus, and the volatile compounds present in this alcoholic drink were identified. Fermentation was performed in a 1000 L reactor at 30 ºC, with initial lactose concentration and hydraulic residence time of 50 g/L and 5 h (dilution rate 0.2 h-1), respectively. The raw spirit (35.4% v/v ethanol) was obtained by distilling the fermentation broth in a pot still. Volatile compounds were quantified by gas chromatography, either by direct injection (with flame ionization detector) or after dichloromethane extraction (coupled with mass spectrometry). Higher alcohols were quantitatively the most abundant group of volatile compounds in this drink, with isoamyl alcohol, isobutanol, and 1-propanol being the most abundant (886.6 mg/L, 542.1 mg/L and 266 mg/L, respectively). Among the total esters, ethyl acetate showed the highest concentration (138.2 mg/L). Other components, such as the terpenes linalool, α-terpineol and geraniol were also identified. Considering that the quality of an alcoholic drink can be evaluated by the ratio between isoamyl alcohol/2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it can be concluded that a novel spirit of acceptable organoleptic character could be produced by whey fermentation with K. marxianus.

Characterisation of volatile compounds in an alcoholic beverage produced by whey fermentation

Dragone, Giuliano; Mussatto, Solange I.; Oliveira, J. M.; Teixeira, J. A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /02/2009 ENG
Relevância na Pesquisa
66.39%
An alcoholic beverage (35.4% v/v ethanol) was produced by distillation of the fermented broth obtained by continuous whey fermentation with a lactose-fermenting yeast Kluyveromyces marxianus. Forty volatile compounds were identified in this drink by gas chromatography. Higher alcohols were the most abundant group of volatile compounds present, with isoamyl, isobutyl, 1-propanol, and isopentyl alcohols being found in highest quantities (887, 542, 266, and 176 mg/l, respectively). Ethyl acetate had the highest concentration (138 mg/l) among the esters. Besides higher alcohols and esters, other components, including aldehydes, acids and terpenes were also identified in the whey spirit. Considering that the quality of an alcoholic beverage can be evaluated by the relation between isoamyl alcohol/2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it was concluded that a novel spirit of acceptable organoleptic characteristics can be produced by cheese whey continuous fermentation with K. marxianus.

Easy and accurate methodology to quantify volatile compounds in fermented beverages

Oliveira, J. M.; Genisheva, Zlatina Asenova; Lima, Luís; Vilanova, Mar
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2009 ENG
Relevância na Pesquisa
66.59%
Volatile compounds of fermented beverages may derive from raw matter, but the majority are formed during fermentative processes. In the some specific cases, e. g. wines, they may also arise during conservation and ageing. These volatiles belong to a diversity of chemical families, including alcohols, esters, fatty acids, volatile phenols, terpenes and norisoprenoids. Levels of individual compounds may range from few ng/L to hundreds of mg/L. Although major volatiles may be analysed directly by gas chromatography, most of them needs a previous step of concentration. Concentration was traditionally achieved by solvent extraction, liquid-liquid mixture, soxhlet and SPE, followed by evaporation; more recently solvent-free extractive techniques SPME and SBSE, became usual due to their detection limits and selectivity. However, these techniques have some drawbacks: environmental aspects when using large quantities of solvents, price, needs of specialized equipment and workmanship. Furthermore, chromatographic detectors may be selective, e. g. pulse flame photometric detector (PFPD) for sulphurous compounds or nitrogenous compounds, or somewhat universal as mass spectrometer (MS). However, although MS permits the quantification of a wide range of volatiles...

Volatile compounds from oak, cherry, chestnut and acacia chips: influence of toasting level

Martins, Nuno; Garcia, Raquel; Gomes da Silva, Marco; Cabrita, Maria Joao
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.53%
In the present study, the volatile composition of wood chips from several botanical species potentially relevant for oenological purposes, namely acacia (unknown specie), chestnut (Castanea sativa), cherry (Prunus cerasus) and oak (Quercus robur) was studied by GC/MS. In order to evaluate the effect of the toasting process on volatile compounds contents we have extended our study to wood chips from the botanical species described above, subjected to different toasting levels, such as untoasted and medium toast. To achieve this goal, a preliminary step comprising the extraction of the volatile compounds by pressurized liquid extraction (PLE) has been performed followed by the analysis and identifi cation of those compounds by GC/MS. The identifi cation was tentatively achieved attending to the characteristic fragmentation patterns of these compounds and by comparison with those reported in the literature. The determination of linear retention indexes has allowed the confi rmation of those attributions. Within this study, we were able to identify 45 compounds, arising from polysaccharides, lipids, lignin and polyphenols degradation. Additionally, 16 other compounds were identifi ed in the different wood species under study although their origin is not fully known. In general...

Effect of ellagitannins, ellagic acid and volatile compounds from oak wood on the (+)-catechin, procyanidin B1 and malvidin-3-glucoside content of model wines

Jordão, A.M.; Silva, J.M.R.; Laureano, O.; Mullen, W.; Crozier, A.
Fonte: ASVO Publicador: ASVO
Tipo: Artigo de Revista Científica
Publicado em //2008 ENG
Relevância na Pesquisa
66.51%
Background and Aims: During ageing in oak barrels, wine undergoes changes because of the release of polyphenols and other molecules from wood. The aim of this study was to evaluate the influence of some oak wood-derived volatile compounds, ellagic acid and oak wood extracts on the levels of (+)-catechin, procyanidin B1 and malvidin-3-glucoside. Methods and Results: Phenolics and the oak wood derived volatile compounds studied were quantified by HPLC and by GC, respectively. Additionally, the new compounds formed in the solutions were characterised by their spectral properties. Ellagic acid and/or oak wood extracts slowed the decline in the levels of (+)-catechin and procyanidin B1. In contrast, the decrease in malvidin-3-glucoside was more pronounced in the presence of ellagic acid and oak wood chip extracts. Furfural slowed (+)-catechin degradation, while breakdown of malvidin-3-glucoside was slightly more pronounced in the presence of guaiacol, furfural, vanillin and eugenol. (+)-Catechin, procyanidin B1 and malvidin-3-glucoside did not significantly affect the rate of the degradation of ellagitannins during the storage time studied. Finally, new HPLC peaks were detected in the solutions containing (+)-catechin and ellagic acid...

Effect of ellagitannins, ellagic acid and volatile compounds from oak wood on the (+)-catechin, procyanidin B1 and malvidin-3-glucoside content in model wines

Jordão, A.M.; Ricardo-da-Silva, J.M.; Laureano, O.; Mullen, W.; Crozier, A.
Fonte: ASVO Publicador: ASVO
Tipo: Artigo de Revista Científica
Publicado em //2008 ENG
Relevância na Pesquisa
66.51%
Background and Aims: During ageing in oak barrels, wine undergoes changes because of the release of polyphenols and other molecules from wood. The aim of this study was to evaluate the influence of some oak wood-derived volatile compounds, ellagic acid and oak wood extracts on the levels of (+)-catechin, procyanidin B1 and malvidin-3-glucoside. Methods and Results: Phenolics and the oak wood derived volatile compounds studied were quantified by HPLC and by GC, respectively. Additionally, the new compounds formed in the solutions were characterised by their spectral properties. Ellagic acid and/or oak wood extracts slowed the decline in the levels of (+)-catechin and procyanidin B1. In contrast, the decrease in malvidin-3-glucoside was more pronounced in the presence of ellagic acid and oak wood chip extracts. Furfural slowed (+)-catechin degradation, while breakdown of malvidin-3-glucoside was slightly more pronounced in the presence of guaiacol, furfural, vanillin and eugenol. (+)-Catechin, procyanidin B1 and malvidin-3-glucoside did not significantly affect the rate of the degradation of ellagitannins during the storage time studied. Finally, new HPLC peaks were detected in the solutions containing (+)-catechin and ellagic acid...

Volatile compounds in the thermoplastic extrusion of bovine rumen

Silva,Ana Carolina Conti e; Bastos,Deborah Helena Markowicz; Arêas,José Alfredo Gomes; Facanali,Roselaine; Marques,Marcia Ortiz M.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 PT
Relevância na Pesquisa
66.45%
The volatile compounds of raw and extruded bovine rumen, extracted by dynamic headspace, were separated by gas chromatography and analyzed by GC-MS. Raw and extruded materials presented thirty-two volatile compounds. The following compounds were identified in raw bovine rumen: heptane, 1-heptene, 4-methyl-2-pentanone, toluene, hexanal, ethyl butyrate, o-xylene, m-xylene, p-xylene, heptanal, limonene, nonanal, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. The following compounds were identified in the extruded material: 1-heptene, 2,4-dimethylhexane, toluene, limonene, undecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane and nonadecane. Mass spectra of some unidentified compounds indicated the presence of hydrocarbons with branched chains or cyclic structure.

Changes in guava (Psidium guajava L. var. Paluma) nectar volatile compounds concentration due to thermal processing and storage

Correa,Maria Ivaneide Coutinho; Chaves,Jose Benicio Paes; Jham,Gulab Newandram; Ramos,Afonso Mota; Minim,Valéria Paula Rodrigues; Yokota,Silvia Rosane Colodeti
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
Relevância na Pesquisa
66.42%
Guava nectars were formulated for approximately 10, 12, or 14 ºBrix, with 40% guava pulp. Sodium benzoate, 500 mg.kg-1 was used as preservative. The Brix value was adjusted with saturated sucrose syrup. The guava nectar was pasteurized (85 ºC/42 seconds) in tubular heat exchanger and then hot filled in 500 mL white glass bottles. The products were stored either at room temperature (25 ± 5 ºC) or refrigerated (5 ± 2 ºC) under fluorescent light exposure and analyzed on the day after processing (time zero) and also 40, 80, and 120 days of storage. Eight compounds were identified and quantified by Gas Chromatography (GC) -Mass Spectrometry (MS): hexanal, (E)-hex-2-enal, 1-hexenol, (Z)-hex-3-enol, (Z)-hex-3-enyl acetate, phenyl-3-propyl acetate, cinnamyl acetate, and acetic acid. There was no significant effect of thermal treatment on the volatile compound concentrations, except for a significant decrease (p = 0.0001) in hexanal and (Z)-hex-3-enyl acetate (p = 0.0029). As for the storage time, there was a much greater decrease in the esters contents, such as (Z)-hex-3-enyl and phenyl-3-propyl acetates. Cinnamyl acetate had the greatest decrease over storage time. Refrigeration was better than room temperature for guava nectar volatile compounds stability over storage time...

The effect of pH on the formation of volatile compounds produced by heating a model system containing 5’-Imp and cysteine

Madruga,Marta Suely; Mottram,Donald S.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/1998 EN
Relevância na Pesquisa
66.49%
The identification of volatile compounds formed from the reactions of Inosine-5’-Monophosphate (5’-IMP) with Cysteine at three different pH (3.0; 4.5; 6.0) and 140 °C were performed using dynamic headspace analysis. The results gave over 90 volatile compounds, mainly heterocyclic compounds, including sulphur containing furans, thiophenes, thiazoles, furans, alkyl sulphides, bicyclic compounds and cyclic sulphides. The studies showed that sulphur-substituted furans, mercaptoketones and alkylfurans were formed mainly at acidic pH, while pyrazines were completely inhibited at high pH. These findings support an earleir observation that pH has a great influence on volatile compounds formed in Maillard type reactions.

Hunter color dimensions, sugar content and volatile compounds in pasteurized yellow passion fruit juice (Passiflora edulis var. flavicarpa) during storage

Sandi,Delcio; Chaves,José Benício Paes; Sousa,Antônio Carlos Gomes de; Parreiras,June Ferreira Maia; Silva,Marco Túlio Coelho da; Constant,Patrícia Beltrão Lessa
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2004 EN
Relevância na Pesquisa
66.35%
Changes in Hunter L, a and b values, glucose, fructose and sucrose contents, concentration of four volatile compounds (ethyl butirate, ethyl caproate, hexyl butirate and hexyl caproate) and furfural, were studied in yellow passion fruit juice (Passiflora edulis var. flavicarpa) pasteurized at 75ºC/60s, 80ºC/41s or 85ºC/27s, during storage at room temperature (25±5ºC) and refrigeration (5±1ºC) for 120 days. While the sucrose content decreased, the glucose and fructose contents increased significantly over storage time. The Hunter L and b values behaved similarly, with a tendency to decrease over time, inversely to Hunter a value. Volatile compound concentrations also decreased over time, inversely to the furfural content. Pasteurization at 85ºC/27s resulted minimum changes in the studied passion fruit characteristics, while that at 75ºC/60s was the most harmful. Storage under refrigeration tended to keep the best quality characteristics of the juice.

Volatile compounds present in traditional meat products (charqui and longaniza sausage) in Chile

Gianelli,María Pía; Salazar,Vanessa; Mojica,Luis; Friz,Miguel
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 EN
Relevância na Pesquisa
66.63%
The aim of this work was to identify and quantify the volatile compounds in five different commercial brands of charqui and longaniza sausages. Volatile compounds were extracted from some samples headspace using solid phase microextraction (SPME). The identification and quantification were made through the gas chromatography with a mass-selective detector (GS-MS). Fifty-four volatile compounds were identified in charqui samples and thirty-two volatile compounds in longaniza sausages. The chemical groups of the volatile compounds found in both the products were: aldehydes, alcohols, ketones, organic acids, furans, aromatic and aliphatic hydrocarbons. Significant differences were found (p<0.05) in the volatile compounds among the brands of longaniza and charqui. A characteristic volatile compounds profile was not found in the analyzed products. However, an important percentage of the volatile compounds in charqui came from the lipid oxidation. In the case of longanizas sausages, volatile compounds come mainly from the carbohydrates fermentation and spices.

Optimisation of stir bar sorptive extraction and liquid desorption combined with large volume injection-gas chromatography–quadrupole mass spectrometry for the determination of volatile compounds in wines

Coelho, Elisabete; Perestrelo, Rosa; Neng, Nuno R.; Câmara, José S.; Coimbra, Manuel A.; Nogueira, J. M. F.; Rocha, Sílvia M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /06/2008 ENG
Relevância na Pesquisa
66.39%
Stir bar sorptive extraction and liquid desorption followed by large volume injection coupled to gas chromatography–quadrupole mass spectrometry (SBSE–LD/LVI-GC–qMS) had been applied for the determination of volatiles in wines. The methodology was optimised in terms of extraction time and influence of ethanol in the matrix; LD conditions, and instrumental settings. The optimisation was carried out by using 10 standards representative of the main chemical families of wine, i.e. guaiazulene, E,E-farnesol, β-ionone, geranylacetone, ethyl decanoate, β-citronellol, 2-phenylethanol, linalool, hexyl acetate and hexanol. The methodology shows good linearity over the concentration range tested, with correlation coefficients higher than 0.9821, a good reproducibility was attained (8.9–17.8%), and low detection limits were achieved for nine volatile compounds (0.05–9.09 μg L−1), with the exception of 2-phenylethanol due to low recovery by SBSE. The analytical ability of the SBSE–LD/LVI-GC–qMS methodology was tested in real matrices, such as sparkling and table wines using analytical curves prepared by using the 10 standards where each one was applied to quantify the structurally related compounds. This methodology allowed, in a single run...

Volatile compounds from oak, cherry, chestnut and acacia chips: influence of toasting level

Martins,Nuno; Garcia,Raquel; Silva,Marco Gomes da; Cabrita,Maria João
Fonte: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional) Publicador: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
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In the present study, the volatile composition of wood chips from several botanical species potentially relevant for oenological purposes, namely acacia (unknown specie), chestnut (Castanea sativa), cherry (Prunus cerasus) and oak (Quercus robur) was studied by GC/MS. In order to evaluate the effect of the toasting process on volatile compounds contents we have extended our study to wood chips from the botanical species described above, subjected to different toasting levels, such as untoasted and medium toast. To achieve this goal, a preliminary step comprising the extraction of the volatile compounds by pressurized liquid extraction (PLE) has been performed followed by the analysis and identi?cation of those compounds by GC/MS. The identi?cation was tentatively achieved attending to the characteristic fragmentation patterns of these compounds and by comparison with those reported in the literature. The determination of linear retention indexes has allowed the con?rmation of those attributions. Within this study, we were able to identify 45 compounds, arising from polysaccharides, lipids, lignin and polyphenols degradation. Additionally, 16 other compounds were identi?ed in the different wood species under study although their origin is not fully known. In general...