Lead in maple syrup produced in Connecticut
1996
Stilwell, D.E. | Musante, C.L.
The lead content of 44 maple syrup samples from 23 Connecticut producers was determined over a period of two seasons. The results ranged from 38 to 948 micrograms/kg and averaged 291 micrograms/kg. In addition, sap and syrup-processing samples were taken from two producers. The lead content (micrograms/L) in all maple grove site sap samples (n = 48) ranged from <0.5 to 19 and averaged 2.6, while those taken exclusively from plastic grove site tanks (n = 35) ranged from <0.5 to 5.4 and averaged 1.1. The higher values were associated with samples taken from galvanized containers. Further contamination of the sap, shown to be caused by the use of a bronze gear pump employed in sap transfer steps, resulted in an average lead content of 19 micrograms/L in sap samples (n = 7) from the final stainless steel storage tanks. These data indicate that contact of any lead-bearing metal by the acidic sap should be avoided. Lead and phosphorus analyses of the syrup-processing samples showed that during the processing of the sap into syrup, significant amounts of lead precipitate out of solution in a form consistent with lead phosphate. Due to the formation of this precipitate, the importance of distinguishing between mixed phase and solution phase samples is emphasized. Finally, on a dry weight basis, the final syrup was no higher in lead content than the incoming sap.
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