Determination of rancidity in meat

Abstract

One of the main factors that affect the quality and the acceptance of meat and meat products and other foods is the oxidation of lipids, known commonly as rancidity, that takes place by reactions of these with atmospheric oxygen. This process leads to the appearance of disagreeable flavors and odors and also to decoloration, nutritional losses and production of potentially toxic compounds. The lipid oxidation can be measured by chemical and physical methods. Diverse analytical tests are used, from simple sensorial evaluation to complex methods to determine volatile compounds related to the rancid aroma. There is no generally applicable method for measuring the degree of lipid oxidation, so that it can accurately measured in all oxidation stages and allows prediction with objective measurements of the moment at which the meat or meat product is made sensorially unacceptable. In spite of its limitations, the TBA test is useful to follow the oxidation of a sample of meat or meat product in different stages. The TBA values must correlate well with the results of the sensorial analysis of a product to be used as oxidation indicators. At the moment, the application of electronic noses seems promissory to determine, easily and quickly, both the global aroma and the specific volatile compounds of the sample, which grants it a great potential for its use in the evaluation of lipid oxidation and in several aspects of the quality control of the meat and meat products.