Respiration

Respiration is the metabolic process by which living cells release energy from nutrients, typically consuming oxygen and producing carbon dioxide and water. In foods it matters in several ways: harvested fruits and vegetables keep respiring, burning sugars and generating heat, and their respiration rate largely sets their storage life, which is why cooling and controlled atmospheres slow it. Microbial respiration drives both desirable fermentations and spoilage, while reaction of foods with oxygen causes oxidative defects such as rancidity in fats and oils and browning in cut produce. Managing oxygen exposure is therefore central to preservation.