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Delgado F.J.,Instituto Tecnologico Agroalimentario | Gonzalez-Crespo J.,Instituto Tecnologico Agroalimentario | Cava R.,University of Extremadura | Ramirez R.,Instituto Tecnologico Agroalimentario
Food Chemistry | Year: 2011

The volatile profile of the Spanish goat raw milk cheese of the protected designation of origin (PDO) "Queso Ibores" was studied at four stages of maturation (day 1, 30, 60, and 90) by the method of solid-phase micro-extraction-gas chromatography-mass spectrometry (SPME-GC-MS) to determinate the characteristic volatile compounds of this cheese and to know the changes in the volatile profile of this cheese during maturation. According to the PDO, Ibores cheese aroma varies between sweet and mild and it has a strong taste, slightly tart. A total of 64 compounds were detected: 14 acids, 18 alcohols, 13 esters, 6 ketones and 13 compounds which could not be classified in these groups. Carboxylic acids were the most abundant volatile compounds in the headspace of Ibores cheese. Content of volatile compounds was significantly modified (P < 0.05) during ripening. The relative total amounts of acids, esters and ketones increased during the first 60 days of maturation. The most characteristic compounds of Ibores cheese aroma were butanoic, hexanoic and octanoic acids, some alcohols (2-butanol and 2-heptanol), ethyl esters of hexanoic and butanoic acids, some methyl ketones (2-butanone, 2-pentanone and 2-heptanone) and δ-decalactone. © 2011 Elsevier Ltd. All rights reserved.

Delgado F.J.,Instituto Tecnologico Agroalimentario | Gonzalez-Crespo J.,Instituto Tecnologico Agroalimentario | Cava R.,University of Extremadura | Garcia-Parra J.,Instituto Tecnologico Agroalimentario | Ramirez R.,Instituto Tecnologico Agroalimentario
Food Chemistry | Year: 2010

The volatile profile of the Spanish soft cheese of the Protected Designation of Origin (PDO) Torta del Casar, made from raw ewes' milk, was studied in four different stages of ripening (1, 30, 60 and 90 days) by the method of SPME-GC-MS. A total of 46 compounds were detected: 13 acids, 9 esters, 4 ketones, 7 alcohols, 3 aldehydes, 7 aromatic compounds and 3 compounds which could not be classified into those groups. Carboxylic acids were the most abundant group isolated; their levels significantly increased during ripening and comprised 61.5% of the total aroma extract at the end of ripening. At day 90, acids of microbial origin were the most abundant, followed by acids derived from amino acids while acids from lipolysis of triglycerides were the least abundant. Esters were the next most important group and their amount also increased significantly during maturation, as did ketones, while alcohols content slightly decreased at the end of the ripening. At day 90, the compounds at highest levels were acetic acid, 3-methylbutanoic acid, butanoic acid propyl ester and 2-butan-one; so these compounds, due to their high levels and their low threshold value could play an important role in the final aromatic profile of this cheese. © 2009 Elsevier Ltd. All rights reserved.

Kovac K.,Instituto Tecnologico Agroalimentario | Diez-Valcarce M.,Instituto Tecnologico Agroalimentario | Hernandez M.,Instituto Tecnologico Agroalimentario | Raspor P.,University of Ljubljana | Rodriguez-Lazaro D.,Instituto Tecnologico Agroalimentario
Trends in Food Science and Technology | Year: 2010

High hydrostatic pressure is a non-thermal technology that eliminates microorganisms with a milder effect on the quality of the foods than that produced by heat treatment. Consequently it can produce microbiologically safe foods, with an extended commercial shelf life and with better characteristics compared to heat-treated foods. Whereas the effect of this technology on foodborne pathogenic bacteria has been extensively studied, there is less information on pressure inactivation of enteric viruses. In this article, we review recent studies on the elimination of foodborne viral risks, and detail the different parameters which could influence the inactivation. © 2010 Elsevier Ltd.

Giraldo E.,Instituto Tecnologico Agroalimentario | Diaz A.,Instituto Tecnologico Agroalimentario | Corral J.M.,Research Center Finca la Orden Valdesequera | Garcia A.,Research Center Finca la Orden Valdesequera
Journal of Proteomics | Year: 2012

Cold storage is being used to increase nectarine fruits' postharvest life. However, low temperatures lead to chilling injury and limit their commercial quality and value. In this study a proteomic approach was used to compare the protein profile between control and cold storage nectarine fruits. Protein extracted from tissue was resolved by two-dimensional gel electrophoresis (2-DE) in the 4-7. pH and 10-200. kDa Mr range. Around 350 spots were well determined, and 11 from 17 spots that showed significant differences were identified by peptide mass fingerprinting (PMF) using matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS). Four differentially expressed proteins were characterized as allergens and were further assessed at the transcription level using quantitative real time-RT-PCR (qRT-PCR). © 2012 Elsevier B.V.

Chafer-Pericas C.,Polytechnic University of Valencia | Maquieira A.,Polytechnic University of Valencia | Puchades R.,Polytechnic University of Valencia | Miralles J.,Instituto Tecnologico Agroalimentario | Moreno A.,Instituto Tecnologico Agroalimentario
Food Control | Year: 2011

Antibiotic residues (sulfonamides and tetracyclines) were determined in Gilthead sea bream (Sparus aurata) and feed samples by means of immunoassays and LC-MS-MS (liquid chromatography-mass spectrometry2). A preliminary study to know the withdrawal time of oxytetracycline in Gilthead sea bream samples was also conducted. It was carried out using immunoassays based on photometric detection of horseradish peroxidase (HRP) activity and time-resolved fluorometric detection of coproporphyrin of Platinum (II) (ELISA and TR-FIA, respectively). The results were compared to those obtained using an LC-MS-MS methodology. They showed that approximately 37 days would be the withdrawal time in order not to exceed the MRL and fish could be commercialized with safety. Regarding feed samples analysis, an LC-MS-MS method was optimized including sample treatment. Average recoveries (n = 6) ranging from 78 to 108% were obtained and precision of the method was between 0.2 and 3%. The same sample treatment was applied to the feed immunoanalysis obtaining satisfactory results.Finally, 20 fish and 4 feed samples were analysed in order to confirm the feasibility of the immunoassays for detecting antibiotic residues. Sulfonamide residues were not detected in any fish sample. Tetracycline residues were detected in some fish samples from marine farms, with total concentrations between 2.1 and 152 ng g-1. In all cases, the obtained results correlated well with those achieved by LC-MS-MS. Therefore, the new methodology allows for food safety of the medicated fish. © 2010 Elsevier Ltd.

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