Comparison of Two Nitrite UV-VIS Spectrophotometric Analysis Methods in Meat Processed Product

Abstract

In most countries, the use of nitrite in meat processed products ei­ther ingoing or the residual amount, is regulated by law. This regulation is continuously updated reflecting the newest and most relevant data after bet­ter understanding nitrite’s potential harmful effects and its transformation pathways in organisms. Sodium nitrite added to meat products is partly con­verted to the heat stable NO-myoglobin and to nitrate by oxidation, acting this way as an antioxidant. These biochemical red ox reactions are not ful­ly understood because they depend on many variables in meat matrixes. Ni­trite residual content is limited at lower than 100 mg/kg product for most of the meat processed products, but because of the abovementioned biochemi­cal often simultaneous reactions, its monitoring should be continuous based on a scientific sampling methodology and accurate methods of analysis. This paper aims to compare two UV-Vis spectrophotometric methods against the reference ISO method for nitrite analysis to recommend their use in specific cases. These methods mainly differ in the nitrite extraction procedures from the meat matrices. The SF UV-Vis AOAC method based on nitrite extraction in natural meat sample conditions and the method proposed by Merino L. in al­kaline conditions are compared to the ISO method by plotting the interaction graph of the data obtained. The results obtained are satisfactory and the au­thor recommends the Merino method when nitrate is to be analyzed in the same sample, otherwise, the AOAC method would be the choice as not much sample handling is required.