Chocolate derived from cocoa beans contains a small amount of caffeine. The bar is coated in chocolate, made from cocoa and milk solids. Melya is coffee flavoured with cocoa powder and honey. Breakfast drinks include coffee, milk, hot cocoa, or tea. Theobromine is the primary alkaloid found in cocoa and chocolate. In some regions, rice is mixed with salt, condensed milk, cocoa, or coffee. For example, isovalderaldehyde seems to produce a sweet, cocoa, and chocolate-like flavor. Serotonin and tryptophan have been found in chocolate with varying cocoa contents. Nutella (; ) is a brand of sweetened hazelnut cocoa spread. Chocolate is a product based on cocoa solid or cocoa fat or both. Common drinks at breakfast are coffee, tea, milk, cocoa (hot or cold) or fruit juices. The final products are round discs of chocolate made of pure compressed cocoa. This is particularly true in certain sectors, such as coffee, cocoa and sugar. The labour was used on banana, rubber, palm oil, and cocoa plantations. Tropical plants are rich in resources, including coffee, cocoa and oil palm.