Oxidative stability during digestion

This chapter focuses on the oxidative stability of n-3 polyunsaturated fatty acids (n-3 PUFAs) delivery systems and n-3 PUFAs fortified foods during digestion, with specific attention given to the long-chain n-3 PUFAs. The topic is of importance since the formation of reactive lipid oxidation products in the gastrointestinal tract (GIT) can lead to unwanted reactions e.g., with proteins, phospholipids, and DNA of the intestinal epithelial layer as well as decrease the amount of n-3 PUFAs being bioavailable in the GIT. Initially, the use of in vitro digestion models to study lipid oxidation is reviewed, after which available literature about the susceptibility of different n-3 PUFA delivery systems-neat oils, emulsions, capsules, and n-3 PUFA-rich foods-to oxidation in the GIT is summarized. In the next part of the chapter, the link between digestion-induced oxidation and initial oxidative status of the n-3 PUFA system, the degree of lipolysis as well as the presence of different pro- and antioxidants is discussed. Based on available findings, some future directions in the current research area are finally given.