Does Anisakis spp. infestation affect the proximate composition, fatty acids, and minerals contents of its host Merluccius merlucccius?

Fish play an important role in human nutrition. They are not only a great source of protein and healthy fats, but also a unique source of essential nutrients such as omega-3 fatty acids. Moreover, most fish are parasitized, and some of these parasites are able to influence the reallocation of resources in their favor and thus reduce the nutritional quality of the fish. The present study was conducted to investigate the impact of the third stage larvae (L3) of Anisakis spp. on the proximate composition, macro-minerals (potassium, calcium, and sodium), and fatty acids of European hake (Merluccius merluccius Linnaeus, 1758). In parasitized female group, our results revealed a decrease (p< 0.005) in the amount of carbohydrate by 6.5%, of calcium by 17%, and of 2 polyunsaturated fatty acids (arachidonic acid (C20: 4w-6), and eicosapentaenoic acid (C20: 5w-3) with 33% and 15% respectively. Simultaneously, an increase by 25% in the level of a single saturated fatty acid C10:0 was noticed. According to the principal component analysis, the parasitized female was wealthy of saturated fatty acids and monounsaturated fatty acids and contains less of polyunsaturated fatty acids, omega-3 fatty acids, and omega-6 fatty acids than the unparasitized female and male. No significant changes were observed in the biochemical composition of male hake, probably due to the low mean intensity of L3 larvae of Anisakis spp. in this group.

Comparison of methods in the recovery and amplificability of DNA from fresh and processed sardine and anchovy muscle tissues.

An important condition for a successful PCR amplification is an efficient DNA-extraction procedure out of a complex biological matrix such as canned fish. In this study we compared six extraction methods, including commercial kit, in terms of DNA yield, purity and time requirement. Such methods were applied to distinguish small pelagic fish species (Sardina pilchardus and Engraulisencrasicolus) among commercial canned products. The quantity and quality of DNA extracted were evaluated using the ratio A260/A280. Data were submitted to principal component analysis (PCA) in order to assess the differences between PCR results of fresh and processed anchovy and sardine muscles. Two main PC characterised the PCR of sardine and anchovy (70% and 69% of all variance): principal component 1 (PC1) (4% and 60%) and principal component 2 PC2 (66.0% and 9%) for sardine and anchovy, respectively. According to the PC1, the PCI/SDS and Chelex extractions (in decreasing order) were positively correlated with results of PCR for both species. Statistical results confirmed that the quality of DNA, with the highest amplicon length obtained from the fresh and the different canned fish, was best preserved using the SDS/PCI precipitation method.