Validation of a gas–liquid chromatographic method for analysing samples rich in long chain n 3 polyunsaturated fatty acids: Application to seafood

Seafood, in general, contains high levels of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), and its consumption has been shown to have positive effects on human health. A method previously reported to be highly effective for PUFA analysis in beef, based on saponification, double extraction and methylation by trimethylsilyl-diazomethane, was validated for seafood fatty acid (FA) determination. The method could be highly suitable for FA analysis in marine tissues since it has shown higher effectiveness in PUFA analysis than classic methods, avoids the production of base-catalyzed artifacts and removes non-saponifiable lipids from the sample. The method was evaluated on three seafood matrices: molluscs (Chamelea gallina), crustaceans (Parapenaeus longirostris) and fish (Pagellus bogaraveo), and 10 FAs representative of seafood were used. Overall recovery values from the three matrices ranged from 80% to 107%. Intra-day RSD ranged between 0.5% and 7.2%, with an average value of 3.4%, while inter-day RSD values ranged between 1.1% and 9.7%, with an average value of 5.7%. Consistent recovery and RSD values were obtained and the method was deemed to produce acceptable accuracy. The applicability of the method to the determination of total FAs in samples rich in LC n-3 PUFA, as seafood products, was demonstratedVersión del edito

Biotechnological enhancement of coffee pulp residues by solid-state fermentation with Streptomyces. Py-GC/MS analysis

The ability of three Streptomyces strains to upgrade the nutritional value of coffee pulp residues from Nicaragua in solid-state fermentation (SSF) conditions was analyzed by Py-GC/MS. The presence in these residues of compounds such as polyphenols, tannins, chlorogenic acids and caffeine prevents their utilization as domestic fodder. The characteristic pyrolysis products derived from polyphenols and polysaccharides were identified both in control and treated coffee pulp being remarkable the decrease achieved in the total polyphenols derived compounds after the growth of the strains. The analysis of these compounds demonstrated that both monomethoxy- and dimethoxy-phenols were degraded. In addition, an increase in the microbial treated coffee pulp of protein content was detected by Kjeldahl method. In summary, changes evidenced in coffee pulp treated by Streptomyces through the application of analytical pyrolysis reveal the biotechnological interest of these bacteria to upgrade a usefulness and pollutant residue to be used for feeding purposes. © 2007 Elsevier B.V. All rights reserved.Peer Reviewe