Optimization of the Enzymatic Extraction of Heme Iron from Pigeon Blood

In this research, heme iron from meat-type pigeon blood was extracted by enzymatic hydrolysis using papain, neutral protease, alkaline protease, flavourzyme or protamex. Based on heme iron content, papain and protamex were selected for dual-enzymatic hydrolysis. Employing one-factor-at-a-time (OFAT) method and orthogonal array design (OAD) with heme iron content and hydrolysis degree as evaluation indicators, the optimum extraction conditions were determined as follows: papain-to-protamex ratio 2:1, pH 7.0, temperature 50 ℃ , blood-to-water ratio of 1:2, enzyme dosage 8000 U/g, and hydrolysis time 3 h. Under these conditions, the extraction yield of heme iron was 95.43 μg/mL, which was significantly increased compared with that obtained using single enzymes.