水产品中总磷和游离磷酸盐含量及其变化规律的分析与研究

Study on the content and variation of total phosphate and free-phosphate in aquatic products

采用铋磷钼蓝法对水产品中总磷和游离磷含量及其变化规律进行了研究。结果表明，不同水产品中总磷和游离磷的含量差异较大。冻虾仁、冻花蚬子、冻带鱼、冻扇贝、海蜇皮和冻鱿鱼圈六种样品中总磷的含量在0．4318～6．7995g／kg范围内，游离磷的含量在0．1164～4．6107g／kg之间。冻虾仁、冻带鱼、冻煮扇贝、冻鱿鱼圈四种样品分别在冷水和在沸水中浸泡，它们中总磷和游离磷含量均呈下降趋势，但在冷水中下降的速率低于在沸水中的。虾仁在三聚磷酸钠、焦磷酸钠、六偏磷酸钠和复合磷酸盐中浸泡1．5h后发现，为使磷酸盐在虾仁上的残留量不超过10mg／kg，且具有较好的保水性，它们的浸泡浓度应该控制在大于2％，小于3％的范围内。铋磷钼蓝法与磷钒钼黄法比较，具有较高的灵敏度和较好的回收率。

The contents of total phosphate and free-phosphate in aquatic products were studied by bismuth phosphomolybdate blue spectrophotometric method.The results showed that the contents of total phosphate and free-phosphate in six kinds of frozen aquatic products were different.These samples were frozen peeled shrimp, frozen flower clams, frozen octopus, frozen scallops, jellyfish and frozen squid.The contents of total phosphate were between 0.4318g/kg and d.7995g/kg in six kinds of samples.The contents of free-phosphate were between 0.1164g/kg and 4.6107g/kg.After the samples were soaked,the phosphate contents decreased significantly during soaking .The contents of total phosphate and free-phosphate in frozen peeled shrimp, frozen ribbonfish,frozen scallops and frozen squid decreased faster in boiling water than in cool water.The shrimp was soaped for 1.5hours in sodium tripolyphosphate, sodium pyrophosphate, sodium hexametaphosphate and cmpound phosphate solution.The results showed that to make phosphate residues on the shrimp not exceed ]0mg/kg,and has good water--holding capacity,the concentration of four kinds of soak liquid should be more than 2%, less than 3%. Bismuth phosphomolybdate blue spectrophotometric method has better sensitivity and recovery than vanadium- molybdenum- yellow- spectrophotometry.