Inhibition of lipoxygenase and blood thinning effects of mackerel protein hydrolysate

Mackerel (Scomber australasicus) muscle was homogenized with deionized water at a ratio of 35: 70 (w/w) for 2 min, boiled for 10 min, and then cooled. Protease N was added to hydrolyze the homogenate at 50C for 2 h, then heated at 90C for 10 min to stop the reaction. The supernatant obtained after centrifugation and filtration was the mackerel protein hydrolysate (MPH). It showed inhibitory effects on both lipoxygenase (LOX)-catalyzed and hemoglobin (Hb)-catalyzed oxidation of arachidonic acid and linoleic acid. Similar inhibitory effects were found on LOX's of soybean, tilapia gill and grey mullet gill. Blood thinning effects were observed in-vitro by mixing MPH with red blood cells. The addition of MPH resulted in a reduced fluid consistency from 0.03 to 0.02, and an increased flow behavior index from 0.67 to 0.87 indicative of a flow behavior becoming closer to Newtonian type and a thinning consistency.