Process optimisation of haemoglobin hydrolysis by complex proteases to produce haem‐enriched peptides and its iron uptake property evaluation by Caco‐2 cell model

Abstract

SummaryIn this study, haemoglobin was hydrolysed by compound protease to produce haem‐enriched peptides in order to improve the bio‐absorptivity of haem iron. The hydrolysis process was optimised through an orthogonal experiment. The molecular weight, solubility and absorptivity of haem‐enriched peptides were also investigated. The optimal hydrolysis process was papain/alkaline protease ratio 6:4, enzyme content 9000 U g−1, hydrolysis at 50 °C and pH 8 conditions for 4 h. After hydrolysis at this condition, the haem released amount and haem/peptide ratio were 89.6% and 28.2%, respectively. The molecular weight of the haem‐enriched peptides was mainly distributed in 3–14.4 kD, and the solubility increased significantly with pH increasing. Caco‐2 cell absorption experiment demonstrated that the iron absorption of haem‐enriched peptides was significantly higher (50.25 ng ferritin per mg protein) than haemin chloride, haemoglobin and collagen plus haemin chloride complex. This study provides a very promising way for the development of iron supplement products.