The Keeping Quality of Dry Whole Milk Spray Dried in an Atmosphere of an Inert Gas

Summary The drying of whole milk or other oxygen-labile materials in an atmosphere of nitrogen or carbon dioxide has been shown to be entirely practical. Drying of the gas to permit re-use can be affected by cooling at an expenditure of not more than 20 gallons of 50° F. water per lb. of water removed. The amount of gas required would be excessive with the conventional spray driers now available. The keeping quality of dry whole milk is influenced materially by the amount of oxygen left in the container, but not by whether the milk is dried in inert gas or in air. At oxygen levels of 1 per cent or below, dry whole milk of low moisture content deteriorates very slowly, even at 100° F.