Mutagenic heterocyclic amine content in thermally processed offal products

Heterocyclic amines (HAs) are potent mutagens formed during heat-processing of proteinaceous food. PhIP is the most ubiquitous and abundant mutagenic HA. In this study several offal products (beef liver, lamb kidney and beef tongue) have been thermally processed and analysed for HAs for the first time. Norharman and harman were the amines most abundant, found at concentrations below 2 ng g-1. PhIP was only formed up to 0.12 ng g-1. Among the rest of HAs analysed, only DMIP, MeIQx and 4,8-DiMeIQx were detectable in cooked kidney and tongue up to 0.25 ng g-1. The influence of cooking additives on HAs formation was evaluated, finding higher levels of norharman and harman, up to 8.87 ng g-1, in liver processed with additives, whereas similar levels of the rest of HAs were found in these samples. The low amounts of HAs found after the prolonged thermal treatments over 200 °C indicates that offal products are among the types of meat that produce lowest exposure to HA.