Non-haem iron availability from pork meat: Impact of heat treatments and meat protein dose

Pork meat heated at 60, 80, 100, and 120 °C (1 h), raw pork meat, BSA, casein and haemoglobin were examined for their effects on in vitro iron availability measured as Fe2+-dialysability, and on iron-reducing capacity following in vitro protein digestion (IVPD-dialysis). The pepsin-digested samples of meat heated at 80, 100, and 120 °C resulted in increased in vitro iron availability. Generally, the capacity to reduce Fe3+ to Fe2+ was higher in the pepsin digests, whereas Fe2+ decreased significantly after pepsin + pancreatin digestion and only part of the Fe2+ was dialysable. Regardless of protein concentration, casein had no effect on in vitro iron availability, while pork meat protein treated at 120 °C showed dose dependency reaching a plateau at 50 mg protein/ml. In conclusion, the major effects on iron availability in vitro was shown in pepsin digests under conditions mimicking those in the duodenal lumen and heat-treatment of meat at 120 °C showed the most pronounced effects.