1,721,069 research outputs found
Gas chromatographic mass spectrometry determination of geosmin and 2-methylisoborneol off-flavor in Mugil cephalus roe
No full textBotargo is the product of the industrial management of fresh roe of the grey mullet (Mugil cephalus). This food product is actually obtained from wild fish caught in different marine areas around the word. The increasing commercial demand of botargo has brought to carry out different fishing systems, gathering the wild mullet in restricted areas, lagoons, to be caught if necessary. This operating mode has caused the appearance of new problems related to the organoleptic approval by the consumers of fish and derived products, following off-flavor contamination derived from different microorganisms present in the lagoons. The most important off-flavor compounds are represented by 2-methylisoborneol (2-MIB) and geosmin (GSM) which give a muddy/musty smell and flavor to the fish. A simple and easy-to-use GC/MS method for the determination of 2-MIB and GSM has been developed. The method has been validated with the following parameters: instrument limit of detection (LOD) and of quantification (LOQ), precision, recovery, and linearity. The method carried out showed good LOD of 1.0 μg/kg and LOQ 2.0 and 5.0 μg/kg for GSM and 2-MIB, respectively. Validation parameters were in close agreement with those reported in the EC SANCO/12571/2013. Recoveries ranged from 80.2 to 121.4 %, with percent relative standard deviation (RSD%) ranging from 0.6 to 18.6 % in the most unfavorable case. Real sample analysis showed the presence of residues of both off-flavor in all botargo samples analyzed, except for sample S0, while in fresh roe samples, only S7 showed important residues of 2-MIB
Gas-Chromatographic mass spectrometry determination of geosmin and 2-methylisoborneol off-flavor in Mugil cephalus roe
No full textGC–ITMS analysis of PAH contamination levels in the marine sea urchin Paracentrotus lividus in Sardinia
No full textThis paper describes the results of a two-year monitoring study examining the pollution of the sea urchin
Paracentrotus lividus by polycyclic aromatic hydrocarbons (PAHs) in Sardinia. GC–ITMS analysis of sea
urchin gonads showed the presence of 11 and 12 PAHs in the samples of Capo Pecora, and Capitana,
respectively. Fluorene, naphthalene and its two degradation products, 1-methyl-naphthalene, and
2-methyl-naphthalene, were detected in all samples analyzed. The RPAH residues showed a similar trend
over the two-year sampling period. Furthermore, the residues in the first year were slightly higher than in
the second year. The information obtained by the multivariate statistical analysis PLS-DA allowed for the
determination of samples based on field site and varying habitat types (rocky reef, and Posidonia seabed).
The results of this study showed that Posidonia sea urchins are contaminated by high molecular weight
PAHs and that Capitana samples are more contaminated due to a higher level of human activity in the
area
Reproductive development versus estimated age and size in a wild Mediterranean population of Octopus vulgaris (Cephalopoda: Octopodidae)
No full textFirst investigation on the relationship between reproductive development and estimated age/size in a wild population of Octopus vulgaris was performed in the Sardinian waters (central western Mediterranean Sea) in order to have a useful tool for integral fishing management in the area. Full sexual maturity was registered from April to August for females with a peak in summer whereas for males it was observed all year round. Size at maturity was 320 g for males (70 mm dorsal mantle length (ML)) and 520 g for females (120 mm ML). From 61 to 465 and from 80 to 390 daily growth increments were counted on the lateral wall of the upper beak, respectively in males and females, obtaining a positive relationship between estimated age and size of the specimens. The sexual maturation was primarily size-dependent with a secondary role played by the age especially in males. The estimated age of 390 and 465 days respectively of the largest female (4661 g) and male (5344 g) as well as that of two males at the end of their lives ('spent') of 310 and 420 days old, have suggested a lifecycle of about 1 year for both genders
Microsatellite markers for population genetic studies of the giant red shrimp Aristaeomorpha foliacea (Crustacea Decapoda)
No full textMicrosatellite markers have been isolated and characterized from the giant red shrimp Aristaeomorpha foliacea in order to investigate on the presence of distinct stocks in the Western Mediterranean Sea. Polymorphism of the newly obtained loci was assessed in a restricted sample of 30 specimens, nine loci provided markers with polymorphism (range 2–19 alleles per locus). Six loci, the most polymorphic and easiest to amplify and to score, were tested in a larger sample of 6 populations from the Western Mediterranean Sea. Microsatellite data revealed a substantial genetic homogeneity and no signs of recent bottlenecks, suggesting the existence of a high gene flow that connects all population
Levels of Mercury and Polychlorobiphenyls in Bluefin Tuna from the Western Mediterranean Sea: A Food Safety Issue?
Full text linkIn this paper, the presence and amount of mercury and polychlorobiphenyls (PCBs) were determined in 23 blue- fin tuna samples collected in the spring of 2012 in Porto Scuso (South West Sardinia, Italy) and Villa Putzu (South East Sardinia, Italy) in order to assess the current levels of these two contaminants in fish muscle and the consequent risk to humans consuming said fish. Values of polychlorobiphenyls in bluefin tuna muscle vary be- tween 0.155 and 1.403 mg/kg f.w.; the average of PCBs in tuna muscle is 0.732 mg/kg f.w. With regard to PCBs the presence of more elevated concentrations is confirmed in larger fish. The results regarding mercury in mus- cle show an average of 0.660 mg/kg f.w. and mercury values vary between 0.140 f.w. and 2.211 mg/kg f.w.; for mercury as well, the highest concentrations were found in the largest bluefin tuna. Six samples, 26% of total, contained more than 1 mg/kg f.w., which is the maximum level set by the European Commission (EC, Regulation n. 1881/2006) for this species. Mercury, in particular methylmercury, poses a risk to public health, therefore, taking into account the important nutritional contribution that tuna fish makes to the diet, it is advisable that women of childbearing age, pregnant and breastfeeding women as well as young children strictly limit their consumption of tuna from this area of the Mediterranean
On the morphometric relationship between beaks and body size in Histioteuthis bonnellii (Férussac, 1835)
No full textSix measurements of 109 beaks (59 males and 50 females) of Histioteuthis bonnellii
(Cephalopoda: Histioteuthidae) caught in the south Sardinian waters were interrelated with the size
(ML) of the specimens. In both sexes, respectively for upper and lower beaks, the lateral wall and the
hood grew faster than other parts (e.g. the rostrum). The analysis of covariance showed different beaks
in the two sexes (p<0.05
Trophic interactions among three rajids, Raja asterias, Raja brachyura and Raja miraletus
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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