Poultry

trient cycling and efficient utilisation of all products and maintain genetic diversity. Smallholder poultry production has an important role to play in feeding the world and, to maximise the benefits, it should be accompanied by improvements to local health services and holistic programs that highlight the links between poultry production, human health and nutrition and sustainable ecosystem services. Poultry production remains at the top of worldwide meat production (right after the pig industry) and the increasing demand for quality by consumers challenges the industry to produce safe, nutritive, appealing, and healthy poultry foods. Oxidative reactions occur throughout the entire food chain, from the living animal at the farm to the final consumer, and at all intermediate stages in between (Estévez, 2015). The genetic pressure toward fast growth rates and large breast muscles has made domestic birds particularly vulnerable to oxidative stress (Petracci et al., 2015; Kuttappan et al., 2016). The occurrence of oxidative damage in tissues leads to impaired biological functions and organic damage that may turn into health problems, compromised poultry performance, and altered meat quality (Fellenberg and Speisky, 2006). Of increasing concern are specific quality defects in poultry meat that have been associated with assorted causal factors, including impaired oxidative metabolism such as wooden breast and white striping (Estévez, 2015). Upon slaughter, the collapse of the endogenous antioxidant defences and the biochemical changes occurring in meat create a pro-oxidative environment that promotes subsequent oxidative reactions (Bekhit et al., 2013). Lipids, proteins, and other food constituents such as heme pigments are oxidized during processing, storage, and culinary preparation of poultry products, causing modifications in their sensory properties and nutritional value (Estévez, 2015). Poultry meat is recognized as highly sensitive to oxidative reactions owing to the high unsaturation degree of the muscle lipids (Min et al., 2008). The onset of rancidity and off-flavors in processed poultry products has been identified as a major concern of lipid oxidation (LOX) (Min and Ahn, 2005). Other studies have also documented the negative influence of protein oxidation (PROTOX) on the functionality, rheological properties and digestibility of muscle proteins (Lund et al., 2011; Estévez, 2011). The oxidation of pigments leads to color modifications with this attribute being critical for consumers when selecting poultry products at the market (Droval et al., 2012). Poultry meat color depends on myoglobin (Mb) concentration and chemical state, while it is affected by numerous factors such as bird age, gender, genetic background, diet, intramuscular fat, meat moisture content, preslaughter conditions, and processing variables (Totosaus et al., 2007). Color defects may appear by mechanisms in which oxidation may not have a direct implication such as bruises, altered postmortem glycogen metabolism, and assorted pathological conditions (Fletcher, 2002). As long as these chemical modifications are major threats to the quality of the poultry meat and processed poultry products, the application of antioxidant solutions seems to be unavoidable (Lund et al., 2011; Bekhit et al., 2013; Estévez, 2015). The growing industrial interest and a prolific scientific production have led to a large variety of antioxidant strategies with a high degree of innovation. In addition to the manipulation of animal feeds, the strategies involving muscle food formulation and innovative packaging solutions have gained considerable popularity (Gallo et al., 2012; Duthie et al., 2013; Bekhit et al., 2013; Delles et al., 2014; Falowo et al., 2014). The present chapter reviews the most recent advances in the field of color and oxidation in poultry and poultry products, emphasizing current concerns and future challenges in relation to consumer perception of these muscle foods.