[Effect of sample storage conditions and treatment on "free nitrite" in meat products]

The aim of the work presented here is to study the effect of different factors on the amount of "free" nitrite in meat products. Two kinds of factors are involved: --factors modifying the amount of "free" nitrite in the product; --factors modifying the amount of nitrite determined as "free". The former are mainly depending on the storage conditions of the products, for instance: low pH, light exposure, high temperature, increase the nitrite losses. The latter are depending on the analysis methodology. A strong physical treatment of the samples, a high temperature during extraction, a long time of extraction, the repetition of the extraction, increase the amount of nitrite determined as "free" by releasing a part of the bound fraction. So, it is very important, for the significance of results in "free" nitrite determination, to know very precisely storage and treatment conditions of the samples.