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

Nicotinamide hemochrome has been reported as one of the potential pigm ents involved in the pinking defect of cooked: uncured turkey. Reflect ance 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% n icotinamide or 0, 75, or 150 ppm sodium nitrite) were treated with pot assium ferricyanide, hydrogen peroxide, sodium dithionite and light (1 076 lux; 0 and 2 min). Treated samples were analyzed with a reflectanc e spectrophotometer in the visible range. Analysis of reflectance wave length ratios of the nicotinamide pigment and correlations of those va lues, indicated that the ratio of 537/553 nm best represented the rela tive quantify of nicotinamide hemochrome (r = 0.933) with minimal inte rference from om nitrosylhemochrome(r = 0.029).