Measuring the Oxidation Potential in Foods

Individual components of food, including lipids, pigments, proteins, DNA, carbohydrates,and vitamins (Kanner 1994), are susceptible to oxidation reactions thatgenerate new chemical products. In some cases, such as oxidative cross-linking ofproteins to manipulate viscosity and gelation in dairy products, this is desirable,but usually, oxidative processes are associated with anti-nutritional and adversesensory outcomes. In meat, oxidative cross-linking of proteins causes toughness(Lund et al. 2011), reduced water-holding capacity in processed meat products, off-avors and odors, and unwanted changes in color. The term “antioxidant” (AOX) is widely used in the context of food, being associated with the chemical stabilization of oxidative processes during storage, and AOX-rich foods are linked with a range of putative health benefits for the consumer. However, the concept of oxidation potential (OP) in foods is neither well defined nor in common use. The purpose of this chapter is to propose a definition of OP and propose a framework for measuring the OP of food components and whole foods. For the purposes of this work, OP will be defined as the extent or initial rate of oxidation of a suitable molecular marker present in a given food, which is sensitive to oxygen-mediated chemical change. This concept is distinct from that of oxidative stress in living organisms, which usually elicits an AOX biochemical response that may be supplemented by AOX-rich foods.