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Farmed European sea bass ( Dicentrarchus labrax) fillets were smoked with three commercial smoke flavorings. Unsmoked and smoked fillets were submitted to oxidative conditions to study their oxidative stability. To this aim, at regular intervals of time under oxidative conditions, their lipids were extracted and studied by Fourier transform mid-infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance (1H NMR). Both kinds of spectra provide markers referred to the beginning and extension of the lipid degradation and of the formation of new compounds resulting from the oxidation process. Obtaining these data from FTIR is easier, simpler, and quicker than it is from 1H NMR, but this latter technique provides, simultaneously, additional interesting information about the sample. The increase of the oxidative stability of sea bass fillets as a consequence of smoking is proved, as well as the influence on this increase of the concentration of certain phenolic smoke components in the fillets. Practical applications: Farmed European sea bass is widely available in the market, in some occasions the supply being greater than the demand. This study could be very interesting for the seafood industry, because smoking of sea bass fillets with smoke flavorings not only extends their shelf-life, but also provides them with special sensory characteristics, diversifying its presence in the market as a new ready-to-eat product. Nevertheless, it must be taken into account that not all the smoke flavorings show the same effect on fish. This study demonstrates that the smoke flavoring composition and its application method have a great influence on the oxidative stability of smoked sea bass fillets. A study of the lipid oxidative stability of unsmoked and smoked sea bass fillets with three different commercial smoke flavorings was undertaken. To this aim, unsmoked and smoked sea bass fillets were submitted to oxidative conditions and their lipids were extracted and analyzed by Fourier transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance (1H NMR) periodically. [ABSTRACT FROM AUTHOR]

Farmed sea bass ( Dicentrarchus labrax) fillets were smoked using one oil-based and two aqueous smoke flavorings. The headspace of the smoked products was studied by solid-phase microextraction followed by gas chromatography/mass spectrometry (SPME-GC/MS). The effect of smoking on several quality and safety characteristics of the fillets and on their evolution during vacuum-packed storage at refrigeration temperature was commented on. Special attention was paid to shelflife length. It was proved that microorganisms able to produce spoilage oxygenated metabolites did not grow in any of the smoked fillets; however, in those smoked with the oily flavoring the growth of microorganisms able to produce sulphur derivatives was observed after 20-25 days of storage. Among the smoked products, great differences were observed in relation to odor, color, texture, safety, and also in their evolution during vacuum-packed storage at refrigeration temperature; no differences were evidenced regarding oxidation derived compounds. Practical Applications Farmed European sea bass is widely available on the market, its supply being on many occasions greater than its demand. The results of this study could be of great interest for the seafood industry because it was demonstrated that smoking of farmed sea bass fillets with smoke flavorings could be an interesting alternative method of offering ready-to-eat sea bass products to consumers. Nevertheless, it was evidenced that many different aspects of this kind of processing should be carefully addressed to obtain a safe ready-to-eat product with optimized sensory properties, and as long a shelflife as possible. [ABSTRACT FROM AUTHOR]

BACKGROUND Fish shelf-life extension is a topic of great interest. In this study the behaviour of salted and unsalted farmed and wild European sea bass ( Dicentrarchus labrax) fillets during storage was analysed through the evolution of their volatile metabolites. Farmed and wild sea bass fillets were brine-salted for 15 or 75 min, or dry-salted, vacuum-packed and stored at 4 °C for up to 1 month, and their headspaces were studied by Solid Phase Micro extraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). RESULTS At the same storage time, unsalted wild fillets contained, in general, a higher number and abundance of volatile compounds coming from microbiological or endogenous enzymatic activity than unsalted farmed ones. The more intense the salting, the lower the number and abundance of microbiological spoilage metabolites, especially in wild samples. The appearance of oxidation metabolites only in dry-salted wild samples evidences that this kind of salting provokes a certain oxidation in these samples. CONCLUSIONS The better performance of farmed than wild fillets suggests that salted farmed fillets, vacuum-packed and stored under refrigeration conditions, could be a successful alternative to diversify the presence of sea bass in the market. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Farmed and wild European sea bass ( Dicentrarchus labrax) could be distinguished by its volatile metabolites, an issue not addressed until now. The aim of this work was to study these metabolites by solid-phase microextraction followed by gas chromatography/mass spectrometry ( SPME-GC/ MS). RESULTS Both farmed and wild sea bass have a great number of volatile metabolites, most of them being in low concentrations. These include alcohols, aldehydes, ketones, alkylfurans, acids, aliphatic and aromatic hydrocarbons, terpenes, sulfur and nitrogen derivatives, 2,6-di- tert-butyl-4-methylphenol and one derived compound, as well as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, this latter compound presumably resulting from environmental contamination. Important differences have been detected between both types of sea bass, and also among individuals inside each group. Farmed specimens are richer in volatile metabolites than the wild counterparts; however, these latter, in general, contain a high number and abundance of metabolites resulting from microbial and enzymatic non-oxidative activity than the former. CONCLUSIONS Clear differences in the volatile metabolites of wild and farmed sea bass have been found. A great deal of valuable information on sea bass volatile metabolites has been obtained, which can be useful in understanding certain aspects of the quality and safety of raw and processed sea bass. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Farmed European sea bass ( Dicentrarchus labrax) fillets were salted by two methods, brine- and dry-salting. Both salted and unsalted fillets were submitted to thermo-oxidative conditions in order to study the evolution of their lipids and their oxidative stability. Lipids were extracted and studied by proton nuclear magnetic resonance (1H NMR). This technique allowed the evolution of the molar percentages of the different kinds of acyl groups (omega-3, docosahexaenoic, eicosapentaenoic, diunsaturated omega-6, and omega-1) to be followed. In addition, the formation of secondary oxidation compounds, such as aldehydes (alkanals, trans-2-alkenals, trans,trans-2,4-alkadienals), could be monitored and quantified by means of this technique, providing information about the oxidative status of the sea bass fillets. No primary oxidation compounds were detected. Moreover, the concentrations of 1,2-diglycerides and phosphatidylcholine were determined. Equations for all the mentioned quantitative determinations were proposed. It was evidenced that the use of salting methods did not provoke the immediate oxidation of sea bass lipids, but reduced their oxidative stability, this effect being more pronounced in dry-salting. Although oxidation began earlier in brine-salted samples than it did in unsalted ones, these latter reached a degradation level of a similar order to that of the brine-salted samples after a certain period of time under the degradative conditions. Practical applications: The results of this study will be useful for optimizing the conditions of European sea bass salting processes, in order to minimize possible lipid oxidation. This is of great importance for sectors of the seafood industry, which focus on this and other fish species with similar lipid content and acyl group proportions, and which are interested in providing high quality food products. The information given by 1H NMR, a rapid and non-destructive method compared with other conventional chemical ones, is very valuable for other researchers who also study fish lipid oxidation processes. The study of the effect of brine- and dry-salting on the lipid oxidative stability of European sea bass ( Dicentrarchus labrax) fillets submitted to thermo-oxidative conditions (50°C and aeration) was carried out by means of proton nuclear magnetic resonance (1H NMR). [ABSTRACT FROM AUTHOR]

2,6-Di-tert-butyl-hydroxytoluene (BHT, E-321) is a synthetic phenolic antioxidant which has been widely used as an additive in the food, cosmetic, and plastic industries for the last 70 y. Although it is considered safe for human health at authorized levels, its ubiquitous presence and the controversial toxicological data reported are of great concern for consumers. In recent years, special attention has been paid to these 14 metabolites or degradation products: BHT-CH2OH, BHT-CHO, BHT-COOH, BHT-Q, BHT-QM, DBP, BHT-OH, BHT-OOH, TBP, BHQ, BHT-OH(t), BHT-OH(t)QM, 2-BHT, and 2-BHT-QM. These derived compounds could pose a human health risk from a food safety point of view, but they have been little studied. In this context, this review deals with the occurrence, origin, and fate of BHT in foodstuffs, its biotransformation into metabolites, their toxicological implications, their antioxidant and prooxidant properties, the analytical determination of metabolites in foods, and human dietary exposure. Moreover, noncontrolled additional sources of exposure to BHT and its metabolites are highlighted. These include their carryover from feed to fish, poultry and eggs, their presence in smoke flavorings, their migration from plastic pipelines and packaging to water and food, and their presence in natural environments, from which they can reach the food chain. [ABSTRACT FROM AUTHOR]

BACKGROUND The lipids of 16 farmed and wild European sea bass ( Dicentrarchus labrax) samples were studied by Fourier transform infrared (FTIR) spectroscopy. The spectroscopic parameters which would be useful when distinguishing between both fish origins were analysed. RESULTS It was shown, for the first time, that the frequency and the ratio between the absorbance of certain bands are efficient and reliable authentication tools for the origin of sea bass. Furthermore, relationships between infrared data and fish lipids composition referring to the molar percentage or concentration of certain acyl groups were also studied. It was proved that some infrared spectroscopic data (the frequency of certain bands or the ratio of the absorbance of others), are very closely related to the composition of sea bass lipids. It was shown for the first time that certain infrared spectroscopic data could predict, with a certain degree of approximation, the molar percentage, or concentration, of omega-3, docosahexaenoic (DHA) and di-unsaturated omega-6 (linoleic) in sea bass lipids. CONCLUSION The consistency of the results confirms the usefulness of FTIR spectroscopy to detect frauds regarding sea bass origin, and to provide important compositional data about sea bass lipids from the nutritional and technological point of view. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Both fresh and slightly oxidized sunflower oils, as models of omega-6 rich lipids, were submitted to in vitro gastrointestinal digestion and studied by 1 H NMR and SPME-GC/MS. Changes in lipolysis degree, lipid composition and oxidative level were studied by 1 H NMR. Three quantitative approaches were used and several equations were newly developed. In oxidized oil digestates slightly lower hydrolysis and a higher advance of oxidation took place during digestion. This latter was evidenced by a greater decrease of lipid unsaturation degree and enhanced generation of oxidation products (cis,trans-hydroperoxy-octadecadienoates, cis,trans- and trans,trans-hydroxy-octadecadienoates). For the first time, the generation of hydroxy-octadecadienoates during in vitro digestion is reported. Furthermore, SPME-GC/MS study of non-digested and digested samples headspaces confirmed that lipid oxidation occurred: abundances of volatile markers increased (including potentially toxic alpha,beta-unsaturated aldehydes), especially in oxidized oils digestates. Markers of Maillard-type and esterification reactions were also detected in the digestates., (Copyright © 2016 Elsevier Ltd. All rights reserved.)