Abstract:

To achieve scientific and effective utilization of tilapias blood as an abundant resource in China, the extraction
conditions of heme from tilapias blood by enzymatic hydrolysis were studied in this paper. Protamex was found as
the best enzyme catalyst for the extraction of heme from tilapias blood. By using single-factor and orthogonal array
designs, the optimum enzymatic hydrolysis conditions were determined as follows: temperature, 40 ℃; pH, 8.0; substrate
concentration, 6 g/100 mL; enzyme/substrate, 8 000 U/g; and hydrolysis time, 2 h. Under these conditions, followed by heat
treatment, acid precipitation and vacuum freeze drying, heme was obtained with a yield of 80.9% and a purity of 28.2%.
This extraction procedure is simple, practical, cost saving and suitable for industrial production of value-added products with
reduced environmental pollution.

Key words: tilapias blood, heme, enzymatic hydrolysis, extraction