QUANTIFICATION OF NICOTINAMIDE HEMOCHROME IN COOKED, UNCURED TURKEY BY REFLECTANCE SPECTROPHOTOMETRY

Abstract

ABSTRACT Nicotinamide hemochrome has been reported as one of the potential pigments involved in the pinking defect of cooked, uncured turkey. Reflectance spectroscopy has been the principle method used to identify this pigment. However, a reliable, easy method to quantify its presence is needed. Cooked turkey samples (containing 0, 0.25, 0.50, 1.0, or 2.0% nicotinamide or 0, 75, or 150 ppm sodium nitrite) were treated with potassium ferricyanide, hydrogen peroxide, sodium dithionite and light (1076 lux; 0 and 2 min). Treated samples were analyzed with a reflectance spectrophotometer in the visible range. Analysis of reflectance wavelength ratios of the nicotinamide pigment and correlations of those values, indicated that the ratio of 537/553 nm best represented the relative quantity of nicotinamide hemochrome (r=0.933) with minimal interference from nitrosylhemochrome (r=0.029).