Optimization of Hydrolysis Conditions for the Production of Iron-Binding Peptides from Scad (Decapterus maruadsi) Processing Byproducts

The scad (Decapterus maruadsi) processing byproduct (SPB) was hydrolyzed by four commercial enzymes, namely, trypsin, flavourzyme, protamex and alcalase, for preparing high Iron-Binding Capacity (IBC) hydrolysate. Alcalase was the best choice for obtaining high IBC hydrolysate from SPB. Response surface methodology using a central-composite design was employed to optimize the enzymatic hydrolysis conditions with alcalase to obtain a maximum hydrolysate yield from the SPB with high iron-binding capacity. The best alcalase hydrolysis conditions were as following: Hydrolysis temperature of 46°C, enzyme substrate ratio of 6040 U/g-protein and hydrolysis time of 66 min, respectively. Under these optimal hydrolysis conditions, the predicted iron-binding capacity was 317.2 µg g^-1, which was consistent with the average of three replicates of 296.2 µg g^-1 obtained in the validation experiments. The IBC of hydrolysate did not displayed linear relationship with antioxidative ability or the Degree of Hydrolysis (DH). Results indicated that the alcalase hydrolysate from scad processing byproduct can be developed into iron supplant ingredients in functional foods.