黄鳍金枪鱼重金属富集特征及食品安全评估

Heavy metal bioaccumulation and food safety of Thunnus albacares from the South China Sea

为了解南海黄鳍金枪鱼(Thunnus albacares)体内重金属富集特征及其食品安全性,对大、中、小3种体型的南海黄鳍金枪鱼肌肉与肝脏中8种重金属(Cd、Ba、As、Cu、Fe、Cr、Se、Zn)含量进行了测定。结果表明,随着体型的变化,各重金属元素的累积特征不同,肌肉中Fe、Se和Cd的含量随着体型变大而不断增加;Zn与Cu则相反;而As、Ba、Cr的含量在3个体型组中无显著变化。在肝脏组织中,Fe、Se、Cu和Cd的含量随体型变大而不断增加;Cr累积趋势相反;Zn、As、Ba的含量在3个体型组中无显著变化。在3个体型组的肝脏中Cd、As、Cu、Fe、Se和Zn含量均显著高于肌肉对应金属元素含量,而Ba、Cr的含量在肌肉与肝脏中无显著差异。在重金属食品安全方面,可食用部分(肌肉)中各重金属元素含量均低于我国食品安全国家标准,但Cd与iAs的单因素污染指数表明南海黄鳍金枪鱼存在轻微的重金属安全风险,因此,建议成人和儿童每日摄入南海黄鳍金枪鱼应分别小于120.00和37.71 g。

Yellowfin tuna(Thunnus albacares) is one of the most popular fish consumed worldwide. It is crucial to determine the risk of yellowfin tuna that heavy metals pose to consumer health. In order to understand the heavy metal bioaccumulation characteristics and food safety in yellowfin tuna from the South China Sea, eight heavy metals(Cd, Ba, As, Cu, Fe, Cr, Se, and Zn) in muscle and liver tissues of the yellowfin tuna were determined. The yellowfin tuna were divided to three groups with different body sizes(large,medium, and small). The findings showed that the bioaccumulation of heavy metal elements in the yellowfin tuna varied significantly with body size. Specifically, the levels of Fe, Se, and Cd in muscle increased with body size(P<0.05), while the levels of Zn and Cu decreased with body size, and the levels of As, Ba, and Cr did not vary significantly with body size(P>0.05). The levels of Fe, Se, Cu, and Cd in liver increased steadily with body size(P<0.05), the Cr level decreased with body size(P<0.05), and the contents of Zn, As and Ba in the tuna with all the body sizes had no significant changes(P>0.05). The levels of Cd, As, Cu, Fe, Se, and Zn were substantially higher in liver than in muscle in the groups of all the three body sizes(P<0.05). In terms of food safety, the concentration of each heavy metal element in muscle was lower than that in the National Food Safety Standards of China(GB 2762-2017). The single-factor contamination index of Cd and iAs suggested the yellowfin tuna from the South China sea have a slight risk of heavy metals to human health, and it is hence recommended that the daily intake of the yellowfin tuna caught in the South China Sea be less than 120.00 g for adults and 37.71 g for children.