A nutritional composition including an oxidizable component and a water-soluble plant extract is provided. The water-soluble plant extract includes rosmarinic acid and has a total phenolic content, such that a ratio of the total phenolic content to the rosmarinic acid is between about 1.1:1 to about 3.5:1. A method of reducing off-flavors and aromas in a nutritional composition having an oxidizable component is also provided.