The present invention relates to an agent for improving the keeping quality of food and drink, comprising a lipase-treated matter of a reaction product obtained by reacting the cells of a lactic acid bacterium with oil and fat in an aqueous medium, a method for improving the keeping quality of food and drink by adding the treated matter, a method for producing food and drink which comprises adding the treated matter to food and drink, and food and drink obtained according to the production method According to the present invention, an agent for improving the keeping quality of food and drink having good flavor, a method for improving the keeping quality of food and drink, food and drink having improved keeping quality, and a method for producing the food and drink can be provided.