The lemon is both a small evergreen tree (Citrus × limon, often given as C. limon) native to Asia, and the tree's ellipsoidal yellow fruit. The fruit is used for culinary and non-culinary purposes throughout the world – primarily for its juice, though the pulp and rind (zest) are also used, mainly in cooking and baking.
Nomilinate was found to be the major acidic limonoid present in seedlings of Citrus limon. Nomilin was converted to at least six acidic metabolites in C. limon, one of which was identified as nomilinate. Lemon juice is about 5% to 6% (approximately 0.3 M) citric acid, which gives lemons a sour taste, and a pH of 2–3. Many lemon flavored drinks and foods are available, including lemonade and sherbet lemons, as well as lemon and seasoning salt as a snack. The distinctive sour taste of lemon juice makes it a key ingredient in many dishes across the world.