Risk-Benefit Assessment Of Intake Of Marine Fish From Zhoushan

Objectives1Analysis of content and composition of fatty acids of marine fish from Zhoushan(1) To survey the content of the main fatty acids of edible part of common marine fish from Zhoushan.(2) To analyse the relationship between contents of total lipids and main long chain n-3polyunsaturated fatty acids in edible part.2Analysis of content of methylmercury of marine fish from Zhoushan(1) To survey the content of methylmercury of edible part of common marine fish from Zhoushan.(2) To analyse the relationship between contents of total lipids and methylmercury in edible part.3Analysis of content of dioxin like compounds of marine fish from Zhoushan(1) To survey the content of dioxin like compounds of edible part of common marine fish from Zhoushan.(2) To analyse the relationship between contents of total lipids and dioxin like compounds in edible part.4Risk-benefit assessment of marine fish from Zhoushan(1) To analyse the net healthy effect by consumption of common marine fish from Zhoushan.(2) To provide preliminary guideline of marine fish consumption for public.Methods1Samples collection31local common edible species of marine fish were collected from Zhoushan archipelago. All samples (6samples/species) were purchased from local piers or markets between September and October,2011. The edible part of all samples were prepared and then homogenized.2Analysis of content and composition of fatty acids of marine fish from ZhoushanTotal lipid in sample was extracted by Folch’s method, fatty acids were separated by gas chromatography and contents of fatty acids were quantified by internal standard.3Analysis of content of methylmercury of marine fish from ZhoushanMethylmercury in samples was transformed into inorganic mercury by K2S2O8and quantified by liquid chromatography-atomic fluorescence spectrometry.4Analysis of content of dioxin like compounds of marine fish from ZhoushanAll samples of same species were mixed equivalently. Total fat in mixed samples was extracted by hexane-dichloromethane (1:1v/v), in which dioxin like compounds were quantified by gas chromatography-mass spectrometry.5Risk-benefit assessment of marine fish from ZhoushanThe net healthy effect of samples were assessed by BRAFO (Benefit-Risk Analysis of Foods)-tiered approach. Its third tier was carried out by FAO/WHO method for deterministic computation of benefit-risk assessment in accordance with the contents of long chain n-3polyunsaturated fatty acids, methylmercury and dioxin like compounds in samples, respectively.Results1Analysis of content and composition of fatty acids of marine fish from ZhoushanThe distribution of mean of fat content (g/100g edible part) was from0.6(Thamnaconus modestus) to13.2(Auxis thazard). Trachinotus ovatus had the highest content of SFA (3014.9±379.0mg/100g edible part) and Seriola quinqueradiata had the lowest content of SFA (89.7±5.8mg/100g edible part). Coilia nasus had the highest content of MUFA (3335.7±383.5mg/100g edible part) and Thamnaconus modestus had the lowest content of MUFA (32.1±16.9mg/100g edible part). Mugil cephalus had the highest content of total n-6PUFA (875.7±506.4 mg/100g edible part) and Seriola quinqueradiata had the lowest content of total n-6PUFA (2.1±1.9mg/100g edible part). Auxis thazard had the highest content of total n-3PUFA (2623.8±426.1mg/100g edible part) and Scoliodon sorrakowah had the lowest content of total n-3PUFA (82.0±13.9mg/100g edible part). Content of total n-3PUFA (r=0.834, P<0.0001), EPA (r=0.734, P<0.0001), DPA (r=0.800, P<0.0001) and DHA (r=0.738, P<0.0001) was positively correlated with content of total lipid in edible part, respectively.2Analysis of content of methylmercury of marine fish from ZhoushanMugil cephalus had the lowest content of methylmercury (7.7±5.3μg/kg edible part) and Seriola quinqueradiata had the highest content of methylmercury (166.6±29.4μg/kg edible part). There is no statistical correlation between contents of methylmercury and total lipid in edible part (r=0.011, P=0.880)3Analysis of content of dioxin like compounds of marine fish from ZhoushanDioxin like compounds were not detected in10species. The distribution of dioxin like compounds content in another21species (ng WHO-TEQ/kg edible part) was from0.011(Collichthys lucidus and Thamnaconus modestus) to2.642(Auxis thazard). Content of dioxin like compounds was positively correlated with content of total lipid in edible part (r=0.485, P=0.006).4Risk-benefit assessment of marine fish from ZhoushanNo intake of marine fish was defined as reference scenario and intake of marine fish of175g per week was defined as alternative scenario in tier1and2.The content of EPA+DHA of3species (Scomber japonicus. Auxis thazard and Coilia nasus) was more than250g/d from reference scenario to alternative scenario in the tier1assessment. The intake of methylmercury/dioxin like compounds of all species was lower than provisional tolerable weekly intake (1.6μg/kg bw/week)/provisional tolerable monthly intake (70pg/kg bw/month) from reference scenario to alternative scenario in the tier1assessment.The intake of long chain n-3polyunsaturated fatty acids from reference scenario to alternative scenario could decrease the risk of coronary heart disease to general population, but it is still no clear dominance about benefit and risk. The tier3assessment carried out by FAO/WHO method:the intake (200g/week) of all species would decrease the mortality. Maternal intake (200g/week) of all species would increase the IQ points of their newborns/infants.Conclusion1Analysis of content and composition of fatty acids of marine fish from ZhoushanThere are significant differences of content of total lipids and of fatty acids among species. Oily fish intake could cause more n-3PUFA related beneficial effect to consumer.2Analysis of content of methylmercury of marine fish from ZhoushanThere are significant differences of content of methylmercury among species. Oily fish intake could not cause increment of exposure of methylmercury to consumer.3Analysis of content of dioxin like compounds of marine fish from ZhoushanThere are significant differences of content of dioxin like compounds among species. Oily fish intake could cause more exposure of dioxin like compounds to consumer.4Risk-benefit assessment of marine fish from ZhoushanAccording to BRAFO-tiered approach, it could be considered that benefit and risk coexist by fish intake, and it is still no clear dominance about benefit and risk. The tier3assessment according to FAO/WHO method indicated that maternal intake of all species would contribute to neurodevelopment in newborns and infants. All species intake would decrease the mortality of general population, but further research of all marine species is needed for more accurate assessment.