酸奶中持久性有机污染物残留影响因素浅析

Pilot Study on Factors Affecting Persistent Organic Pollutants Residue Levels in Yogurt

为探究影响酸奶中POPs残留的因素,采用化学提取预富集与GC-ECD相结合的方法,测定了产自北京六个不同区域以及产自中国不同城市相同品牌酸奶中和酸奶及其原料奶中OCPs、PCBs的残留水平。结果显示:北京地区酸奶中OCPs残留水平呈西南>>南部、城区>>东南、东北的分布,PCBs残留呈城区>>西南>南部、东南>>东北的分布;产自不同城市相同品牌酸奶中OCPs、PCBs残留水平与组成因地而异,表明奶源环境是影响酸奶中POPs残留水平的重要因素之一;酸奶中HCHs、DDTs、PCBs残留水平低于其原料奶,原因可能与酸奶生产过程中的加热灭菌环节和微生物发酵过程有关。

To understand the factors affecting persistent organic pollutants residue levels in yogurt, the concentrations of OCPs and PCBs in yogurt specimens from six production areas of northeast, center, southeast, south, southwest of Beijing and from different Chinese cities with same commercial brand were determined by GC-ECD combined with chemical separation methods. Meanwhile, the levels of OCPs and PCBs in yogurt and their raw milk samples were also analyzed. The results indicated that the concentrations of OCPs in yogurt from Beijing area were in the order of southwest 〉〉 south, center 〉〉 southeast, northeast, and PCBs in the order of center 〉〉 southwest 〉 south, southeast 〉〉 sortheast. Also, both concentrations and compositions of OCPs and PCBs in same commercial brand yogurt samples produced in different regions significantly varied. This fact suggested that the environmental status of raw milk is a key factor to affect the pollutants residues in yogurt. Further, the levels of HCHs, DDTs and PCBs in yogurt were much lower than those in their raw milk, which is likely relevant to the manufacturing technology of yogurt, including heat treatments and microorganisms zymolysis during storage.