Catecholamines are phenolic biogenic amines which occur in tissues of plants and animals. Some, for example adrenaline and noradrenaline, act as hormones, and high preslaughter levels of these compounds as a result of stress may be associated with poor meat quality, including pale, soft, exudative or dark, firm, dry defects. Aerobic oxidation of catecholamines in the presence of catechol oxidases results in formation of melanins, and hence browning of plant foods. They illustrate how stress physiology connects directly to food quality, from farm to fork.