An object of the present invention is to provide a method for more strongly preventing oxidation of unsaturated fatty acids using a simple method. In particular, an object of the present invention is to provide a method for suppressing both an unpleasant odor that appears in an initial stage of storage and an unpleasant odor that appears subsequently. The present invention has been accomplished by finding that an unpleasant odor that appears in an initial stage of storage, as well as an unpleasant odor that appears subsequently, can both be suppressed in an unsaturated-fatty-acid-containing water-in-oil composition comprising an aqueous phase A having a pH adjusted to 3.1 to 8 in which at least one member selected from the group consisting of ascorbic acid and polyphenols is dissolved, an aqueous phase B having a pH adjusted to 0.5 to 3 in which at least one member selected from the group consisting of ascorbic acid and polyphenols is dissolved, and an oil phase containing an unsaturated fatty acid, the aqueous phase A and the aqueous phase B, each having a particle size of 500 nm or less, being finely dispersed individually in the oil phase.

[Problem] To provide: a method for improving the stability of an oil or fat composition for frying use by preventing the coloration of the oil or fat composition and also preventing the increase in an anisidine value and the decrease in the content of a tocopherol compound in the oil or fat composition when a food material is fried with the oil or fat composition; and a stabilizer for an oil or fat composition for frying use. [Solution] A method for stabilizing an oil or fat composition for frying use according to the present invention is characterized in that a chlorophyll compound is added at a concentration of 0.05 to 2 ppm by mass inclusive to an edible oil or fat. It is preferred that the chlorophyll compound is added in the form of a chlorophyll compound-rich solution having a chlorophyll compound concentration of 1 to 1,000 ppm by mass inclusive. A stabilizer for an oil or fat composition for frying use according to the present invention contains a chlorophyll compound as an active ingredient.