Identification of six canned tuna species using DNA-based methodology was studied. DNA was degraded during the canning process of fish muscle:  DNA fragment sizes that ranged from <100 up to 200 bp were obtained from canned tuna muscle, whereas DNA sizes for frozen tuna muscle ranged from <100 up to 20 000 bp. Amplification of DNA from canned tuna muscle was carried out using primers flanking a region of cytochrome b gene of 126 bp. Sequences from PCR-amplified DNA of six tuna species were studied for polymorphic sites; seven diagnostic positions were identified in this fragment for the species studied. The suitability of a genetic distance measurement with phylogenetic tree construction method for the identification of canned tuna species using two cytochrome b sequences (299 and 126 bp) was studied. PCR-amplified DNA from canned tuna was also analyzed by using three restriction endonucleases, BsiYI, MboI, and MnlI. The restriction fragments allowed for the identification of the six tuna species studied. Keywords: Canned tuna; species identification; cytochrome b; genetic distance; RFLP−PCR

Nanoparticles (NPs) have emerged as a potential tool to improve cancer treatment. Among the proposed uses in imaging and therapy, their use as a drug delivery scaffold has been extensively highlighted. However, there are still some controversial points which need a deeper understanding before clinical application can occur. Here the use of gold nanoparticles (AuNPs) to detoxify the antitumoral agent cisplatin, linked to a nanoparticle via a pH-sensitive coordination bond for endosomal release, is presented. The NP conjugate design has important effects on pharmacokinetics, conjugate evolution and biodistribution and results in an absence of observed toxicity. Besides, AuNPs present unique opportunities as drug delivery scaffolds due to their size and surface tunability. Here we show that cisplatin-induced toxicity is clearly reduced without affecting the therapeutic benefits in mice models. The NPs not only act as carriers, but also protect the drug from deactivation by plasma proteins until conjugates are internalized in cells and cisplatin is released. Additionally, the possibility to track the drug (Pt) and vehicle (Au) separately as a function of organ and time enables a better understanding of how nanocarriers are processed by the organism.

Skin collagen of six discarded fish species was analyzed and compared. Acid soluble collagen (ASC) was extracted; a characteristic sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profile for type I collagen was obtained, except for Chimaera mostrosa. Contents of collagen calculated from HPro (31.85% average) were higher than those determined from ASC extracts (17.75% average), with Galeus spp. being the species with the higher percentage. Amino acid analysis revealed the typical composition of collagen, with very few differences among species. Specific profiles were obtained after protease digestion. Denaturation temperature of ASC correlated well with imino and hydroxyproline contents.Results demonstrate the feasibility of using the obtained collagens in different industrial applications.

Present production of wild fish resources is around 85 millions tonnes per year, and the maximum long-term potential of marine capture fisheries of some areas and fisheries has been reached. However, not all that is obtained from the sea is adequatelly used and three clearly differentiated factors can be taken into account to explain this fact: discards, wastes on board and byproducts and wastes ashore. Although some efforts has been employed for changing this situation a more efficient and inteligent use of the natural resources extracted from sea and wasted is needed. In this article the present utilization of discards and fishery wastes and the future trends and the expected future of fishery industry are presented.

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The formation of fluorescent compounds was tested as a quality assessment during the frozen storage of sardine at -18°C (up to 24 mon) and at -10°C (up to 120 d). The fluorescence ratio between two excitation/emission maxima (393/463 and 327/415 nm) was studied in the aqueous (δF aq ) and organic (δF or ) extracts after Bligh and Dyer extraction of the white muscle. Fluorescence results were compared to common quality indices [total volatile base-nitrogen (TVB-N); conjugated dienes; thiobarbituric acid index (TBA-i); and free fatty acids (FFA)]. δF aq showed good correlations with storage time (r = 0.80 and r = 0.72 at -18 and -10°C, respectively) and TBA-i (r = 0.92 and r = 0.81). Principal-component analysis grouped δF aq with quality indices that are sensitive for the assessment of fish damage during frozen storage at both temperatures . According to these results, fluorescence detection of interaction compounds in the aqueous phase can provide an accurate method to assess quality differences during frozen storage of fish. JAOCS 75, 575-580 (1998).

Sardine alterations during chilled storage (0ЊC) were investigated by measuring the fluorescence ratio between two excitation/emission maxima (393/463 nm, 327/415 nm) and compared with common quality indices. Sardines were also maintained at 15ЊC to accelerate all reactions occurring at 0ЊC. Other quality indices (total volatile base-nitrogen, free fatty acids, formation of conjugated dienes, and thiobarbituric acid values) were determined and the use of the fluorescence ratio (fluorescence shift, ␦F) was analyzed. A high correlation was found between the ␦F and the total volatile base-nitrogen (r ϭ 0.93, at 0ЊC; r ϭ 0.92, at 15ЊC).

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