Tanja Bogdanović

As, Cd, Hg and Pb in four edible shellfish species from breeding and harvesting areas along the eastern Adriatic Coast, Croatia.

Four species of shellfish (Mytilus galloprovincialis, Ostrea edulis, Chlamis varia and Venus verrucosa) were collected during the autumn 2011 and spring 2012 along the eastern Adriatic coast from six shellfish harvesting areas (all species) and 13 breeding sampling areas (mussels) to assess As, Cd, Hg and Pb levels and the human risks of shellfish consumption. The mean metal concentrations (wet weight) in the examined species ranged from 1.420 to 9.575mg/kg for As, 0.034 to 1.270 for Cd, 0.005 to 0.680 for Hg and 0.140 to 2.072 for Pb. Examination of the spatial distribution of As, Cd, Hg and Pb revealed statistically significant differences among the studied areas. Since the concentrations were below the maximum prescribed by the laws of the EU and Croatia (the concentrations slightly exceeded the upper limits for three samples; Pb, Cd and Hg) and the hazard index, (HI) for Cd, Hg and Pb were below 1 and the target cancer risk (TR) for As was lower than 1×10(-6), there is no human health risk of consumption of shellfish from Croatian waters.

Development and Application of Quality Index Method Scheme in a Shelf-Life Study of Wild and Fish Farm Affected Bogue (Boops boops, L.)

UNLABELLED Quality index method scheme was developed for raw bogue (Boops boops) and evaluated it in a shelf-life study, using samples from wild fish aggregations at fish farms (BF) and from area not influenced by the fish farms (BW). Different environment influenced the shelf life of bogues; thus the maximum ice storage, evaluated from cooked samples, was found to be 17 d for BF and 12 d for BW. The calculated quality indexes (QIs) evolved linearly with storage time on ice (QI(BF) = 0.968x + 0.583, R(2) = 0.947, Std. Err. Est. = 1.41; QI(BW) = 1.212x + 0.474, R(2) = 0.972, Std. Err. Est. = 0.95). The multivariable analysis was used to identify the most effective variables during spoilage evolution. The sum of all demerit points showed higher correlation (R > 0.99) then any single parameters itself, indicating that the individual parameters could not replace the usage of 20 demerit points QIM scoring scheme in sensory assessment. The impact of farming cages was observed in fat (BF > 19%; BW < 2%) and water content (BF = 55%; BW = 77%) of bogues, but also in pH, dielectric properties, thiobarbituric acid index, and volatile amine changes. High correlations of these parameters with storage time and sensory assessment were observed. PRACTICAL APPLICATIONS The catch landings of bogue make this species very important in the Mediterranean fishery production. The effect of finfish farms makes individual fish samples of this species different in size and chemical content, thus changing the rate and in which their postmortem changes occur. The practical use of the article is a new developed and species adopted descriptive scheme for bogue, ready to use for scientific and industrial freshness assessment providing the information on fish quality and its remaining shelf life in ice, taking into account the environmental conditions such as catching ground.

Role of biogenic amines in the post-mortem migration of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) larvae into fish fillets.

Infective third-stage larvae (L3) of nematode Anisakis spp. have been recognized as one of the major food-borne threats in lightly processed fish products in Europe, particularly in the Mediterranean region. Therefore, the effect of different storage temperatures of fish on larval post-mortem migration from visceral cavity into fillets is an important parameter to take into account when evaluating the risk for consumer safety. The European anchovy (Engraulis encrasicolus) were caught during fishing season, a subsample of fillets was checked for the presence of Anisakis larvae at capture (mean abundance=0.07), and the rest was stored at four different temperatures (-18, 0, 4 and 22°C) in order to count migrating larvae and measure the production of biogenic amines over a period of time. Larvae were identified by morphological features and molecular tools. Post-mortem migration was observed in fillets stored at 0 and 4°C after three and five days, respectively, but not at 22 and -18°C. In case of storage at 22°C for two days, at the onset of putrefaction of the visceral organs, larvae migrated out of the visceral cavity towards the fish surface. Measured pH and biogenic amine profile during storage indicated that certain biochemical conditions trigger larval migration into fillets. Likewise, migration was observed at pH ~6.4 when sensory degradation of the fish was markedly visible. Although larval migration was delayed for approximately four days at a temperature of <4°C the correlation between pH and abundance of A. pegreffii larvae in the fillet was high and statistically significant at both 0 (r=0.998, p<0.01) and 4°C (r=0.946, p<0.05). Out of eight biogenic amines measured, cadaverine and putrescine levels correlated the most with the post-mortem migration at 4°C, while tyramine levels were significant at both temperatures.

NUTRITIONAL QUALITY OF DIFFERENT FISH SPECIES FARMED IN THE ADRIATIC SEA

We investigated the nutritional quality of commercially important farmed fish species: sea bream (Sparus aurata), sea bass (Dicentrarchus labrax), dentex (Dentex dentex), and turbot (Scophthalmus maximus). The omega-3 fatty acid content of dentex was twice as high as that of any other fish species, and its eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid contents were 2-4 times higher. The recommended n-3/n-6 ratio was present in all the fish species, but the recommended polyunsaturated/saturated fatty acid ratio was not present in the turbot. All the fish species, except turbot, met the recommended atherogenic index, thrombogenic index, and ratio of hypocholesterolaemic to hypercholesterolaemic fatty acids, whereas the highest flesh lipid quality value was observed in the dentex.