EFFECTS OF pH, TEMPERATURE AND ENZYME TO SUBSTRATE RATIO ON THE ANTIOXIDANT ACTIVITY OF PORCINE HEMOGLOBIN HYDROLYSATE PREPARED WITH PEPSIN

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Abstract

ABSTRACT

The effects of pepsin-assisted hydrolysis conditions on the antioxidant activity (AA) of porcine hemoglobin hydrolysate (PHH) were investigated in this study. Effects of temperature, pH and enzyme to substrate ratio on the AA were evaluated and compared using response surface methodology. Temperature and pH were the major factors affecting the AA. Enzyme to substrate ratio influenced AA to a lesser extent. The model for the AA of PHH was established and it showed a good fit with the experimental data. The PHH (1 mg/mL) showed the strongest AA (65.43%) at 40.4C, pH 1.6, enzyme to substrate ratio = 1.6% (w/w). The degree of hydrolysis (DH) and AA of pepsin-assisted hydrolyzed PHH were significant higher (P < 0.05) than chemical hydrolyzed PHH whatever the hydrolysis time. There was no correlation between DH and AA.

PRACTICAL APPLICATIONS

Blood protein is a by-product of the meat industry with high nutritional and functional value but high pollution power. The proportion of hemoglobin in blood protein is 60–70%. Enzymatic hydrolysis of food proteins generally results in profound changes in the bioactivities of proteins treated. The porcine hemoglobin hydrolysate prepared with pepsin at the optimal hydrolysis conditions was a potent natural free radical scavenger, which would be expected to protect against oxidative damage in living systems and might be potential anti-oxidant for application in food, cosmetic and medicine industries.

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