Effect of a polyphenol–vacuum packaging on lipid deterioration during an 18-month frozen storage of Coho Salmon (Oncorhynchus kisutch)

10 páginas, 3 tablas, 2 figuras.-- The final publication is available at www.springerlink.comA packaging system combining a polyphenolrich film and vacuum (PPRF–VP) was applied to farmed coho salmon (Oncorhynchus kisutch) muscle for an 18- month storage (−18 °C). For it, two different concentrations of polyphenol compounds (namely, p-coumaric and ferulic acids) obtained from a barley husk extract were applied (PPRF–VP conditions) and compared to vacuum packaging without polyphenol presence (vacuum control; VP condition) and to packaging in the absence of vacuum and polyphenols (control; CP condition). The study was addressed to lipid hydrolysis and oxidation development and to lipid changes related to nutritional value. Both PPRF–VP conditions provided an inhibitory effect (p< 0.05) on conjugated diene and fluorescent compound formation in frozen salmon. Compared to CP condition, vacuum packaging (PPRF–VP and VP conditions) led to lower (p<0.05) peroxide and anisidine values and to an inhibitory effect (p<0.05) on α- and γ-tocopherol losses. No effect (p>0.05) of polyphenol presence and vacuum packaging could be inferred on free fatty acid formation (hydrolysis development) and on polyunsaturated fatty acid retention (polyene index assessment). A low rancid odour development was observed in all kinds of fish samples, this being lower (p<0.05) in fish kept under vacuum (PPRF–VP and VP) conditions.Peer reviewe

Medida del grado de insaturación de aceites y grasas comestibles por espectroscopia infrarroja y su relación con el índice de yodo

An spectroscopy method to fast determination of the degree of unsaturation of oils and fats is described by measurement of intensity of the olefinic band at 3007 cm-1 Using SNGLE program, the peak heigt and peak area and also 1st derivate and 2nd derivate at 3007 cm-1 are calculated and relationships between these parameters and iodine values are studied. The best relationships were obtained with the measurements of net absorbance (r=0,9992: error index=1,75%) and area (r=0,9992; error index= 1,77%).Se describe un método de espectroscopia IR para determinar de forma rápida el grado de insaturación de grasas y aceites comestibles, basado en la medida de la banda correspondiente al enlace olefínico a 3007 cm-1 Por medio del programa de análisis cuantitativo SNGLE se calcula la absorbancia neta, el área, la 1ª derivada y la 2ª derivada de la banda a 3007 cm-1 y se estudia la relación de estos parámetros con el índice de yodo. La mejor correlación y el menor índice de error se obtiene con las medidas de la absorbancia neta (r=0,9992; ind. error=1,75%) y el área (r=0,9992: ind. error=1,77%) de dicha banda

Lipid Oxidation Inhibition in Frozen Farmed Salmon (Oncorhynchus kisutch ): Effect of Packaging

3 pages, 1 table.Coho salmon (Oncorhynchus kisutch) has recently attracted a great interest as a farmed product. This research focuses on its commercialisation as a frozen product. For it, an advanced storage technology combining vacuum and a polyphenolic rich-film was applied for a 9-months storage period (–18°C). The study was addressed to lipid hydrolysis and oxidation changes and to endogenous antioxidant content in salmon muscle. No effect of packaging conditions could be observed on free fatty acid formation. However, vacuum packaging conditions provided a partial inhibition of primary (peroxide) and secondary (anisidine value) lipid oxidation development; this inhibitory effect was accompanied by a lower tocopherol isomers loss. The employment of a film including polyphenolic compounds led to a partial inhibition of α-tocopherol breakdown and to a lower secondary (anisidine value) and tertiary (fluorescent compound formation) lipid oxidation development. A partial inhibitory effect on lipid oxidation development is concluded for the employment of a polyphenolic compound rich-film packaging when applied to farmed coho salmon.This research was carried out in the frame of the Project No. 2006 CL 0034 (2007–2008), granted by the U. Chile-CSIC Cooperation Program. Coho salmon fish was provided by Aquachile SA (Puerto Montt, Chile).Peer reviewe

Xenoestrogens released from lacquer coatings in food cans

We present data showing that some foods preserved in lacquer-coated cans and the liquid in them may acquire estrogenic activity. Hormonal activity was measured using the E-screen bioassay. The biological activity of vegetables packed in cans was a result of plastic monomers used in manufacturing the containers. The plastic monomer bisphenol-A, identified by mass spectrometry, was found as a contaminant not only in the liquid of the preserved vegetables but also in water autoclaved in the cans. The amount of bisphenol-A in the extracts accounted for all the hormonal activity measured. Although the presence of other xenoestrogens cannot be ruled out, it is apparent that all estrogenic activity in these cans was due to bisphenol-A leached from the lacquer coating. The use of plastic in food-packaging materials may require closer scrutiny to determine whether epoxy resins and polycarbonates contribute to human exposure to xenoestrogens.This work was supported by grant 94/1551 from the Fondo de Investigaciones Sanitarias (FIS), Spanish Ministry of Health

The estrogenicity of bisphenol A-related diphenylalkanes with various substituents at the central carbon and the hydroxy groups

This work was reported in part at the meeting Estrogens in the Environment IV: Linking Fundamental Knowledge, Risk Assessment, and Public Policy held in Washington, DC, 19-21 July 1997.The chemical structure of hydroxylated diphenylalkanes or bisphenols consists of two phenolic rings joined together through a bridging carbon. This class of endocrine disruptors that mimic estrogens is widely used in industry, particularly in plastics. Bisphenol F, bisphenol A, fluorine-containing bisphenol A (bisphenol AF), and other diphenylalkanes were found to be estrogenic in a bioassay with MCF7 human breast cancer cells in culture (E-SCREEN assay). Bisphenols promoted cell proliferation and increased the synthesis and secretion of cell type-specific proteins. When ranked by proliferative potency, the longer the alkyl substituent at the bridging carbon, the lower the concentration needed for maximal cell yield; the most active compound contained two propyl chains at the bridging carbon. Bisphenols with two hydroxyl groups in the para position and an angular configuration are suitable for appropriate hydrogen bonding to the acceptor site of the estrogen receptor. Our data suggest that estrogenicity is influenced not only by the length of the substituents at the bridging carbon but also by their nature. Because diphenylalkane derivatives are widespread and their production and use are increasing, potential exposure of humans to estrogenic bisphenols is becoming a significant issue. The hazardous effects of inadvertent exposure to bisphenol-releasing chemicals in professional workers and the general populations therefore deserve investigation.This research was supported by grants from the Spanish Ministry of Health (FIS, 95/1959) and the Andalusian Regional Government Department of Health (Consejerla de Salud, 96/159)

Evaluación físico-química de aceite pigmentado obtenido de la cabeza de camarón

In this work the proximal analysis, physicochemical characterization, fatty acid profile and astaxanthin content of pigmented oil obtained by fermentation shrimp heads are presented. Lipids are the major components in the oil (95%). The saponification number is 178.62 mg KOH/g, iodine value 139.8 cg iodine/g, and the peroxide value was not detected. Density and viscosity were 0.92 mg/ml and 64 centipoises, respectively. The highest contents of fatty acids were linoleic (C18:2n6), oleic (C18:1n9) and palmitic (C16:0). Eicosapentaenoic acid (C20:5n3, EPA) and docosahexaenoic acid (C22:6n3, DHA) account for 9% of the total. The content of astaxanthin was 2.72 mg/g dry weight. The pigmented oil is a dietary source of nutrients with high value such as astaxanthin.En este trabajo se presenta el análisis proximal, caracterización físico-química, perfil de ácidos grasos y contenido de astaxantina en aceite pigmentado aislado por fermentación láctica de los residuos de camarón. Los lípidos son los componentes mayoritarios (95%). El índice de saponificación es 178.62 mg KOH/g, el de yodo 139.8 cg yodo/g, y los peróxidos no fueron detectados. La densidad y la viscosidad fueron de 0.92 mg/ml y 64 centipoises, respectivamente. Los ácidos grasos en mayor cantidad fueron el linoleico (C18:2n6), oleico (C18:1n9) y palmítico (C16:0). El ácido eicosapentaenoico (C20:5n3, EPA) y el docosahexaenoico (C22:6n3, DHA) suman el 9% del total. El contenido promedio de astaxantina fue de 2.72 mg/g base seca. El aceite pigmentado es una fuente dietética de nutrientes con alto valor como la astaxantina

Changes in Sensory and Physical Parameters in Chill-Stored Farmed Coho Salmon (Oncorhynchus kisutch)

11 páginas, 1 figura, 6 tablasThis work focuses on changes in sensory and physical properties of coho salmon (Oncorhynchus kisutch) during chilled storage (24 days). A marked change (p < 0.05) in the results of sensory analysis was found in the flesh of raw chilled fish (fresh odor, elasticity, hardness, oxidized odor) and in the cooked flesh of the chill-stored fish (firmness, neutral flavor, oxidized flavor, oxidized odor) samples. Additionally, physical parameters (gaping, cooking loss) also showed changes (p < 0.05) during chilled storage. According to odor and flavor descriptors (fresh odor, oxidized odor, neutral flavor), salmon fish were not acceptable after 17 days of chilled storageThis work was supported by the Universidad de Chile (Chile)-Consejo Superior de Investigaciones Científicas (CSIC, Spain) Program (Project 2003 CL 0013) and the FONDECYT Program (Chile; Project Number 1120627)Peer reviewe

Effect of a polyphenol–vacuum packaging on lipid deterioration during an 18-month frozen storage of Coho Salmon (Oncorhynchus kisutch)

10 páginas, 3 tablas, 2 figuras.-- The final publication is available at www.springerlink.comA packaging system combining a polyphenolrich film and vacuum (PPRF–VP) was applied to farmed coho salmon (Oncorhynchus kisutch) muscle for an 18- month storage (−18 °C). For it, two different concentrations of polyphenol compounds (namely, p-coumaric and ferulic acids) obtained from a barley husk extract were applied (PPRF–VP conditions) and compared to vacuum packaging without polyphenol presence (vacuum control; VP condition) and to packaging in the absence of vacuum and polyphenols (control; CP condition). The study was addressed to lipid hydrolysis and oxidation development and to lipid changes related to nutritional value. Both PPRF–VP conditions provided an inhibitory effect (p< 0.05) on conjugated diene and fluorescent compound formation in frozen salmon. Compared to CP condition, vacuum packaging (PPRF–VP and VP conditions) led to lower (p<0.05) peroxide and anisidine values and to an inhibitory effect (p<0.05) on α- and γ-tocopherol losses. No effect (p>0.05) of polyphenol presence and vacuum packaging could be inferred on free fatty acid formation (hydrolysis development) and on polyunsaturated fatty acid retention (polyene index assessment). A low rancid odour development was observed in all kinds of fish samples, this being lower (p<0.05) in fish kept under vacuum (PPRF–VP and VP) conditions.Peer reviewe