PURPOSE: To obtain an oil or fat composition free from ill odor and preservable for a long period suppressing the deterioration of a polybasic unsaturated fatty acid existing in the oil or fat composition, by sterilizing an oil or fat composition containing a polybasic unsaturated fatty acid and aseptically packaging in a sate dipped in a liquid.

CONSTITUTION: An oil or fat composition such as soup is prepared by mixing (A) 2W20wt% oil phase containing ≤10wt% polybasic unsaturated fatty acid such as γlinolenic acid based on the whole oil or fat composition and (B) other components such as dairy products, vegetables, water, etc. The oil or fat composition is sterilized by conventional UHT process and filled and packaged aseptically in a state dipped in a liquid.