Characterization of heme from tilapias blood extracted by protamex hydrolysis

In order to make the scientificly and effectively use of tilapias blood resources,an innovative method to extract heme from tilapias blood was established. The procedure consists of protamex hydrolysis,acid precipitation,vacuum freeze drying,etc. The results showed that the yield of extracted heme was 80.9%,and the purity was 28.2%. The characterization analysis included spectral characteristics,molecular weight,Fe2 +residual rate and microscopic examination,which demonstrated the sample's characteristic wavelength was 385 nm and the principal component was heme. 20% of the heme was the combination of heme and macromolecular peptides and the molecular weight was 5~10 ku,but 75% of the heme probably was the monomer or combined with small molecular peptides,the molecular weight was less than 5 ku.The Fe2 +residual rate of sample was 37%,indicated that protecting measure was necessary while extraction. The related research results could provide important theoretical basis and technical supports for the development and application of hemoglobin of tilapia blood in the future.