Patent ID: 7375240

Claim:
A process comprising bringing a fat or oil containing diglycerides in an amount of 50 mass % or greater and having a transition metal content of 5 ppm or less into contact with steam while forming a thin film of the fat or oil, wherein the fat or oil is brought into contact with steam while forming a thin film by a method of causing the fat or oil to flow downwards in a distillation column filled with a structured packing material and flowing steam so as to countercurrently bring the steam into contact with the fat or oil, wherein the fat or oil and steam are brought into contact with each other under the conditions of the fat or oil temperature of from 250 to 280° C. for 1 to 15 minutes, wherein the fat or oil having a transition metal content reduced to 5 ppm or less is employed, and wherein the transition metal content is reduced by adsorption treatment or a method of adding a chelating agent to the fat or oil and washing the resulting mixture with water.