The effects of heating and chemical treatment on the haem and non-haem iron content of heat-induced porcine blood curd

Abstract

The effect of heating temperature (40–80°C), time (0–50 min), additions of ascorbic acid (0–5 g litre−1) and sodium nitrite (0–200 mg litre−1) on total, non-haem and haem iron of heat-induced porcine blood curd (a famous edible blood food in Taiwan) was investigated. The results show that non-haem iron content increased significantly (P < 0.05) when heated at above 55°C and was enhanced linearly (r = 0.96) with heating time at 80°C, while haem iron decreased relatively. In addition, a non-haem iron increase was observed in ascorbic acid, the maximum found with treatment at 4 g litre−1. On the contrary, haem iron content increased with the presence of sodium nitrite and there was a significant change with addition above 50 mg litre−1.