Method of refining oils with polycarboxylic acids

Claim 1

IN THE CONTINUOUS PROCESSES OF ALKALI-REFINING DEGUMMED GLYCERIDE FATS AND OILS CONTAINING FREE FATTY ACIDS AND ALKALI-REFINING NONDEGUMMED GLYCERIDE FATS AND OILS CONTAINING FREE FATTY ACIDS IN WHICH AT THE SAME TIME THE GUMS ARE DECOMPOSED BY THE ALKALI AND DISSOLVED THEREIN, INCLUDING THE STEPS OF MIXING THE SAME WITH AN AQUEOUS ALKALI SOLUTION IN AN AMOUNT TO NEUTALIZE THE FREE FATTY ACIDS AND DECOMPOSE AND DISSOLVE THE GUMS, IF ANY AND CENTRIFUGALLY SEPARATING AN AQUEOUS PHASE CONTAINING SOAPSTOCK, GUM RESIDUES, IF ANY, AND UNDESIRABLE IMPURITIES FROM A REFINED OIL PHASE, THE IMPROVEMENT WHICH COMPRISES INTRODUCING AT ANY STAGE IN THE ALKALI REFINING STEP A SMALL AMOUNT UP TO A FRACTION OF 1% OF AN ALIPHATIC POLYCARBOXYLIC ACID ON AN ANHYDROUS WEIGHT BASIS RELATIVE TO THE AMOUNT OF OIL TREATED TO REDUCE THE REFINING LOSSES.