Nitrite reaction with meat constituents

Our objective in this manuscript is twofold — first to describe the biological setting (meat) in which the chemistry of nitrite occurs, and second to provide an analysis of research accomplishments relating directly to what is known about reaction of nitrite with the constituents of meat. In the relatively short time span of the ten years mentioned above, a substantial amount of literature has appeared. It would be duplicative effort to repeat all of the pertinent details here. Rather, the reader is referred to a recent review on reactions of nitrite in meat (1 which provides extensive documentation and enumerates several other pertinent major reviews. 

In fact, as will be indicated later in this manuscript, the proteins of meat are the major constituent with which nitrite reacts and explain the largest proportion of the nitrite lost from analytical detection during curing. While considerable discussion has occurred about this so called protein bound nitrite, little has been substantiated about identification and quantitation of the reaction products. Protein bound nitrite has been of concern in analysis for free nitrite because depending on conditions of analysis, some portion of it may be released and measured. 

It is obvious from the foregoing that to select and quantitate a reaction of nitrite with a given constituent of meat is a tremendous challenge. Another approach has been to conduct bookkeeping type experiments with a label in order to balance nitrite loss from analysis against detection of the label in another form. 

In meat curing, nitrite is traditionally used for developing the pink, heat-stable pigment. Its other important role is the inhibition of the outgrowth of Clostridium botulinum spores in pasteurized products and, in some countries, in several types of smoked fish. Nitrite also serves as an antioxidant and contributes positively to the development of the flavor of cured-meat. The undesirable side-effect, however, is the reaction of nitrite with amino groups of food constituents, leading to the formation of NNCs. 

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