Glucose oxidases, EC 1.1.3.4, are flavoenzymes that convert beta-D-glucose into gluconic acid and hydrogen peroxide. Foods and drinks use them to scavenge glucose and oxygen together, protecting colour and flavour in liquid egg white, fruit juices, beverages, beer, wine, mayonnaise, bread dough and cheese. The same oxygen-hunger serves biosensors that measure glucose and packaging systems that strip oxygen to fight oxidative spoilage. Dosing balances benefit against the peroxide formed, which other enzymes or formulation steps manage, often by pairing with catalase that breaks the peroxide down.