Studies On Migration And Control Of Food Contaminations In Three-piece Metal Cans

The migrations of various contaminations such as melamine(MEL) and bisphenol compounds(BPA, BADGE, BFDGE) from the coating of three-pieces metal cans as food packaging would pose a potential harm to health, which has attracted wide concerns. Based on the dectection methods established, the migration of contaminations from inner coating of intermediates produced during the whole production process of three-piece cans were tracked to determine the control points and the control measures was then proposed accordingly; the stabilities of migration compounds were further explored; besides, the migration models of these compounds were established according to the migration rules. All these studies provided effective supports to ensure the safety of three-piece metal cans applied in food packaging.The determination methods with liquid chromatography tandem mass spectrometry(HPLC/MS-MS) for MEL, BPA, BADGE, BFDGE and their derivatives were established.Hilic Plus RRHD chromatographic column was used for the separation of MEL, the validation data showed the linear ranges were 0.5~50 μg/L, and the detection limit was 0.2μg/L. Eclipse Plus C18 column was for the separation of 10 kinds bisphenol compounds,the linear ranges and the detection limit were 1~200 μg/L and 0.5 μg/L. The methods were extended to detect these chemicals in acidic beverages and water-based simulants with recoveries and relative standard(RSD) of 92.2%~102.3% and less than 10%.The migration levels of MEL and bisphenol compounds from internal coating of intermediates of three-piece cans were investigated. Results showed that the amounts of these contaminations increased significantly after the process of full spraying, which therefore was deemed as a critical control point. The material acceptance of full spraying lacquers was more effective than process optimization to control contaminations.The stabilities and transformation rules of BADGE and its derivatives in simulants after heat treatment in accordance with the sterilizing and storage conditions of cans were studied.Results showed that after atmospheric pressure sterilization and during the storage, BADGE,BADGE·H2O and BADGE·HCl hydrolyzed and transformed to their hydrates,BADGE·H2O·HCl, BADGE·2H2O and BADGE·2HCl were stable under the same conditions,However, the chloride of BADGE in ethanol transformed into BADGE and its hydrates after high pressure sterilizing.Finally, the migrations of MEL and bisphenol compounds into acidic beverages under different storage conditions were investigated. On the basis of experimental data, migration models were established to predict the migration trend of these compounds. Results showed that the predicted data of established model and experimental data matched well.