1. THE METHOD OF PACKAGING SPRAY DRIED POWDERED MILK HAVING AIR ASSOCIATED THEREWITH BOTH BETWEEN THE PARTICLES OF SAID POWDERED MILK AND IN THE INTERIOR OF SAID PARTICLES SO AS TO REDUCE THE OXYGEN CONTENT OF SAID POWDERED MILK, WHICH METHOD COMPRISES THE STEPS OF, INTRODUCING THE POWDERED MILK INTO A CONFINED SPACE TO FORM A BULK MASS THEREIN, DISPLACING THE AIR BETWEEN SAID PARTICLES IN SAID SPACE WITH INERT GAS, WHEREBY THE INERT GAS DIFFUSES INTO THE EXTERIOR OF THE PARTICLES TO REPLACE OXYGEN THEREIN AND THE REPLACED OXYGEN DIFFUSES INTO THE INERT GAS BETWEEN THE PARTICLES TO INCREASE THE OXYGEN CONTENT OF THE INERT GAS BETWEEN SAID PARTICLES, FURTHER DISPLACING THE GAS BETWEEN SAID PARTICLES WITH FRESH INERT GAS TO CAUSE FURTHER DIFFUSTION AND REPLACEMENT OF OXYGEN WITH INERT GAS IN THE INTERIOR OF SAID PARTICLES WHILE DISCHARGING THE DISPLACED GAS FROM SAID SPACE, CONTINUING THE FURTHER DISPLACEMENT OF THE GAS BETWEEN THE PARTICLES WITH FRESH INERT GAS AND THE DISCHARGE OF DISPLACED GAS FROM SAID SPACE AT LEAST UNTIL THE OXYGEN CONTENT OF THE DISCHARGED GAS IS REDUCED TO BETWEEN APPROXIMATELY 1 AND 3% WHEN CALCULATED RELATIVE TO A DISCHARGE FLOW OF .01 TO .15 CUBIC FEET PER HOUR PER 100 POUNDS OF POWDERED MILK, AND THEREAFTER REMOVING THE RESULTING POWDERED MILK FROM SAID SPACE AND PACKAGING THE SAME IN SEALED PACKAGES UNDER NON-OXIDIZING CONDITIONS.