Determination Of Content Of Polyphosphate In Seafood And Risk Assessment

Polyphosphate is a kind of important food additives in the food industry, they can keep food moisture, regulate pH, buffer and chelate metal ions.In the storage and transportation of aquatic products, adding a certain amount of polyphosphate can increase weight of products. In light of the present status that the concentration of polyphosphates in aquatic products were high, an ion chromatography method for the determination of polyphosphates was established, the residue levels of phosphates in aquatic products of Qingdao were investigated, the risk assessment of phosphate was carried out according to the food safety riskanalysis theory, and the influence of sodium tripolyphosphate on the body weight and bone development of growing rats were investigated.Ion chromatography method was established for the determination of orthophosphate, pyrophosphate, tripolyphosphate and trimetaphosphate in aquatic products. The chromatographic conditions include AS11-HC column, a mobile phase of KOH in gradient elution mode. The flow rate was1.0mL/min and they were detected by suppressed conductivity detector. The four compounds were separated well. The linears were well, and the average recoveries were80.3-106.9%. This method is sensitive, accurate and time-saving. It can be used for the determination of polyphosphates in aquatic products.In order to provide scientific basis for the safety and risk assessment of aquatic products, the residue levels of phosphates in aquatic products of Qingdao from different market sources were investigated. The concentration of phosphates in506aquatic products, which including91samples of14species of frozen marine fishes,64samples of frozen shrimps,201samples of frozen shrimp meat,50samples of surimi products and100samples of grilled fishes, were determined by ion chromatography method. The results showed that most aquatic products had high orthophosphate contentration, and the levels of pyrophosphate, and tripolyphosphate were higher than other polyphosphates. Significant differences on types showed that the four kinds of phosphates conerntration in aquatic product samples were great(P<0.05). The grilled fishes, frozen marine fishes, frozen shrimps, frozen shrimp meat and surimi products were arranged respectively according to the orthophosphate concentration from high to low. The frozen shrimp meat, grilled fishes, surimi products, frozen shrimps and frozen marine fishes were arranged respectively according to the pyrophosphate concentration from high to low. The frozen shrimp meat, surimi products, frozen shrimps, grilled fishes and frozen marine fishes were arranged respectively according to the tripolyphosphate concentration from high to low. The trimetaphosphate concentrations of most of the aquatic products were lower than the detection limit. According to the production of differem kinds of fishery products in2010China Fisheries Statistical Yearbook, the data of total phosphates concentration in fishery products was weighted.The results showed that the range of total phosphates was665.77-19938.02mg/kg, the median was2967.78mg/kg, the mean value was2337.82mg/kg, and the distribution of total phosphates concentration was not normal(.P<0.05).According to the food safety risk analysis theory, risk assessment of phosphates in aquatic products was carried out. The results showed the average daily dose of residents was6.97mg/(kg-d), the mean value of the hazard quotient was0.03, below1, which suggested that there was little risk to residents only by dietary intake of fishery products.The influence of sodium tripolyphosphate on the body weight and length, the tibia and femur length and weight, and minerals of serum, jejunum femur of rats were investigated. The results showed sodium tripolyphosphate had an inhibitory effect on rat growth and bone growing, and there were certain dose-effect relationship. Calcium carbonate was helpful to reduce the inhibitory action.