Sterilizing method by substituting the dissolved oxygen in milk or the like with nitrogen gas, a product thereof and an apparatus for nitrogen gas substitution

An apparatus for substituting dissolved oxygen present in a protein- or saccharide-containing liquid with a nitrogen gas, which apparatus comprises:

• a material tank;
• a nitrogen gas substituting tank having at least one spray nozzle therein;
• a liquid feed pipe connecting said material tank to said nitrogen gas substituting tank;
• a nitrogen gas mixing means installed in said liquid feed pipe;
• nitrogen gas supply means connected by a nitrogen gas pipe to said liquid feed pipe at a position upstream of said nitrogen gas mixing means in said liquid feed pipe;
• said liquid feed pipe including a branched portion, said nitrogen gas supply means being connected to said liquid supply pipe at a position between said branched portion and said nitrogen gas mixing means, said branched portion connecting said liquid feed pipe to said at least one spray nozzle;
• pump means for pumping protein- and saccharide-containing liquid from said material tank to said liquid feed pipe;
• and
• flow rate control means positioned at each of the liquid feed pipe upstream of said branched portion, said branched portion of said liquid feed pipe, and said nitrogen gas supply means.