The Effects of Irradiation and Antioxidants on Myoglobin Derived From Beef Hearts

Abstract

To determine the effect of antioxidants and irradiation on meat color, myoglobin (Mb) was extracted from beef hearts. Mb was treated with one of four antioxidants (control, citric acid (CA), ethylenediaminetetraacetic acid (EDTA) or propyl gallate (PG)) and irradiated at 0.00, 1.25 or 2.50 kGy. Samples were then evaluated for thiobarbituric reactive substances (TBARS), pH, Hunter color, absorbance and reflectance over the visible range (400--700 nm) and absorbance at 280 nm. Protein denaturation, protein concentration, and met- (MMb), deoxy- (DMb) and oxy- (OMb) myoglobin percentages were calculated from reflectance and absorbance data. Antioxidants influenced color, % protein denaturation, and % protein concentration. CA and AA had higher L*, a* and b* values than EDTA, PG and control. AA had larger % protein values pre- and post-irradiation. Irradiation had no effect on pH, TBARS, color, % protein denaturation, % protein concentration, and %MMb, %DMb, and %OMb. These results indicate that antioxidants have more influence on beef color than irradiation.