The leaves, both fresh and dried, are used in traditional Mediterranean cuisine. They have a bitter, astringent taste and are highly aromatic, which complements a wide variety of foods. A tisane can be made from the leaves. When burnt, they give off a mustard-like smell and a smell similar to burning wood, which can be used to flavor foods while barbecuing. Rosemary is high in iron, calcium and vitamin B6. Rosemary extract has been shown to improve the shelf life and heat stability of omega 3-rich oils, which are prone to rancidity.