龙头鱼甲醛本底含量及其影响因素的研究

目的了解龙头鱼中甲醛本底含量及影响因素,为食品安全监管部门评判市售龙头鱼有无人为添加甲醛提供科学依据。方法在排除外源性甲醛污染的条件下采集龙头鱼共计55份,在冷藏(冰箱4℃)条件下,按存放时间设计不同的梯度进行检测,其中两件样品采取匀浆处理后冷藏。从农贸市场及饭店随机采集31份龙头鱼样品当日检测。结果龙头鱼在活体状态时即可检出甲醛,之后随存放时间的延长,甲醛含量逐渐增高,冷藏5天时达最高值,之后随鱼体腐败变质,甲醛值又逐渐下降。可食状态下检测值范围为(10.40～223.80)mg/ kg,中位数为68.05mg/kg。龙头鱼经匀浆处理后冷藏,甲醛含量可达327.52mg/kg。排除外源性甲醛污染龙头鱼与市场随机采集的龙头鱼甲醛含量两者无显著差异(P=0.400)。结论我国现行的水产品标准中对甲醛的限量值值得商榷。浙江市场销售的龙头鱼未发现有人为添加甲醛的情况。

Objective： The study was conducted to investigate the content of intrinsic formaldehyde in Bombayduck, so as to provide the supervision departments a scientific basis on judging whether formaldehyde is added or not. Methods： 55 samples of Bombayduck were collected and the content of intrinsic formaldehyde was examined at different phases of cold storage. Two samples were homogenized and the content of formaldehyde were determined. 31 samples of Bombayduck were collected from wet markets and restaurants and the content of intrinsic formaldehyde were determined on the same day. All samples were carefully protected against contamination of exogenous formaldehyde in the process from collection to examination. Results：The concentration of formaldehyde was detected in the living fish. In frozen fish samples the concentration was increased as the storage time increased, with the peak value at 5th day. Then it declined with the deterioration of fish. The values of formaldehyde content in edible state were 10. 40 223, 80 mg/kg and the median value is 68.05mg/kg. The content in homogenate was 327.52mg/kg. There was no significant difference between formaldehyde contents of Bombayduck which is excluded of exogenous formaldehyde pollution and that collected from markets （P = 0. 4000）. Conclusions：The national standard which requires zero content of formaldehyde in marine products needs further discussion. No Bombayduck sold in Zhejiang＇s markets was found added formaldehyde artificially.