The effect of processing temperature and addition of mono- and di-valent salts on the heme- nonheme-iron ratio in meat

Heme iron from meat has a superior bioavailability compared to non-heme iron and, from a nutritional point of view, processing of meat should be optimised to maintain high levels of heme iron. The effects of heat treatment and addition of NaCl and other ionic species, on the heme-iron/nonheme-iron ratio (H/NH) in meat, have been studied by measuring heme and non-heme iron in minced, vacuum-packed pork. Heating temperature has a gross effect on H/NH with a decrease in heme iron content of 62% after heating at 80°C for 2 h. The correlation (r2) between heme and non-heme iron determinations was −0.92. NaCl increases H/NH in cooked meat by preventing the heme molecule from liberating iron, probably by an increase in the ionic strength of the meat. Calcium ions have a gross negative effect on H/NH during cooking of meat. These effects of sodium and calcium on H/NH in heat treated meat have not been previously reported.