市售核桃油氯丙醇酯、缩水甘油酯和邻苯二甲酸酯 污染水平及来源分析Pollution levels and source of chloropropanol esters, glycidyl esters and phthalates in commercial walnut oil

为了调查市售核桃油中氯丙醇酯、缩水甘油酯（GEs）以及邻苯二甲酸酯类塑化剂（PAEs）等污染物的污染水平和来源，对30个市售核桃油样品中3-氯-1，2-丙二醇酯（3-MCPDE）、2-氯-1，3-丙二醇酯（2-MCPDE）、GEs以及18种PAEs含量进行测定，并进行膳食暴露评估，同时，通过测定核桃油精炼过程中这些污染物的含量变化分析其来源。结果表明：30个市售核桃油样品中有22个样品检出氯丙醇酯或GEs，28个样品检出PAEs；3-MCPDE含量范围为未检出~1 259.86 μg/kg，检出率为70.00%，平均值为414.34 μg/kg，中位数为37276 μg/kg；2-MCPDE含量范围为未检出~717.82 μg/kg，检出率为6.67%；GEs含量范围为未检出~803.64 μg/kg，检出率为3.33%；PAEs中邻苯二甲酸二正丁酯（DBP）含量范围为未检出~3.39 mg/kg，平均值为056 mg/kg，中位数为0.47 mg/kg，超标率为56.7%，邻苯二甲酸二(2-乙基)己酯(DEHP)含量范围为未检出~11.64 mg/kg，平均值为1.53 mg/kg，中位数为0.60 mg/kg；超标率为30.0%，邻苯二甲酸二异壬酯(DINP)含量范围为未检出~6.10 mg/kg，无超标情况。膳食暴露评估结果表明，目前市售核桃油中3-MCPDE、DBP、DEHP的含量均处于安全水平，引起健康危害的风险较低。通过对核桃原油及精炼过程中核桃油的氯丙醇酯、GEs以及PAEs含量检测分析发现，PAEs主要来源于制油过程的外源迁移，氯丙醇酯以及GEs是精炼过程中的产物。随着脱臭温度的提高，PAEs含量降低，而氯丙醇酯以及GEs含量却急剧升高，说明精炼工艺与这些污染物的水平密切相关。综上，在核桃油生产中需要严格把控核桃原料的质量，同时改进和优化精炼工艺，以控制核桃油中氯丙醇酯、GEs以PAEs等污染物水平，提高核桃油品质。In order to investigate the pollution level and source of chloropropanol esters, glycidyl esters (GEs) and phthalates (PAEs) in commercial walnut oil, the contents of 3-chloro-1,2-propanediol ester (3-MCPDE), 2-chloro-1,3-propanediol ester (2-MCPDE), GEs and 18 PAEs in 30 batches of commercial walnut oil were analyzed and detected, and dietary exposure assessment was performed. The sources of these pollutants were analyzed by measuring the changes in the contents of these pollutants during the refining process. The results showed that among 30 commercial walnut oils, chloropropanol esters or GEs were detected in 22 samples, and PAEs were detected in 28 samples. The range of 3-MCPDE content in commercial walnut oil was from undetected to 1 259.86 μg/kg, with an detection rate of 70.00%, an average of 414.34 μg/kg and a median of 372.76 μg/kg. The content of 2-MCPDE ranged from undetected to 717.82 μg/kg, with an detection rate of 6.67%. The content range of GEs was from undetected to 803.64 μg/kg, with an detection rate of 3.33%. The content of di-n-butyl phthalate (DBP) in PAEs ranged from undetected to 3.39 mg/kg, with an average of 0.56 mg/kg, a median of 0.47 mg/kg, and an exceeding rate of 56.7%. The content of di (2-ethylhexyl) phthalate (DEHP) ranged from undetected to 11.64 mg/kg, with an average of 1.53 mg/kg, a median of 0.60 mg/kg, and an exceeding rate of 30.0%. The content range of diisononyl phthalate (DINP) was from undetected to 6.10 mg/kg, and there was no exceeding standard. The results of dietary exposure assessment showed that the contents of 3-MCPDE, DBP and DEHP in commercial walnut oil were at a safe level, and the risk of health hazards was low. Through the detection and analysis of the content of chloropropanol esters, GEs and PAEs in crude walnut oil and refined oil in different refining stage, it was found that PAEs were mainly derived from the exogenous migration of the oil production process. In contrast, chloropropanol esters and GEs were products in the refining process. With the increase of deodorization temperature, the content of PAEs decreased, while the content of chloropropanol esters and GEs increased sharply. The refining process was closely related to the level of these pollutants. To sum up, it is necessary to strictly control the quality of walnut raw materials, improve and optimize the refining process, so as to control the levels of chloropropanol esters, GEs and PAEs, and improve the quality of walnut oil.