Iron, heme, and nitrosyl-heme content in Spanish meat derivatives

Heme and nitrosyl-heme have been pointed out as responsible for the association between processed meats and cancer. The objective of this study was to obtain reliable data on the current proximate composition, total iron, total heme, zinc-protoporphyrin, and nitrosyl-heme content in 40 meat derivatives consumed in Spain. The determination of heme and nitrosyl-heme was achieved using the classical spectrophotometric determination of the acetone extracts and compared with the chromatographic determination of these extracts which enables the separation of other porphyrins. Results revealed a high variability of heme and nitrosyl-heme contents in meat derivatives which may reflect differences in meat derivatives ingredients and formulations, manufacturing processes, storage, and cooking conditions. In addition, certain derivatives contain considerable amounts of nitrosyl-heme despite the fact there was no addition of nitrite or nitrate. Although the comparison of both methodologies for heme and nitrosyl-heme determination were in good agreement, the chromatographic method is advisable as some interfering compounds may lead to an overestimation when using the classical spectrophotometric determination. In the Spanish adult population and based on the obtained data the estimated total iron, nitrosyl-heme, and total heme intakes resulting from meat derivatives consumption, were 14.6 mg/day, 528.6 µg/day, and 1676.2 µg/day, respectively.