Green coffee beans contain chlorogenic acidThe coffee bean is the seed of the coffee plant and is found in the plant’s red or purple fruit. Although they are seeds, they are called beans because they are bean-like in appearance. The fruit, which are often called coffee cherries or coffee berries, usually contain two seeds, with their flat sides against each other. The two most common coffee plants are Arabica and Robusta. 75-80% of all coffee produced is Arabica and 20% is Robusta. The coffee plant grows in a belt, "the bean belt" or "coffee belt" between the tropics of Cancer and the Tropic of Capricorn. South America is the largest exporter of coffee and accounts for about 45% of all exports. Most coffee comes from Brazil. The plants grow to be about 5-10 meters high, and the older they get, the less they branch, and the more leaves and fruit they have. The trees are planted in rows, with plenty of space between each plant. Some farmers plant fruit trees around the plant or plant coffee trees on slopes, as they require very specific conditions to thrive. For Arabica coffee, a temperature between 15-24°C is ideal, and for Robusta 24-30°C, and they must receive between 15-30cm of rain per year. Heavy rain is needed especially in the beginning of the season when the fruit develops, and as the fruit matures, less rain is required. When the fruit has ripened, it is almost always picked by hand, through the so-called selective harvesting where only the ripe fruit is picked, or "strip-picking" in which all the fruit on a stalk is picked in one go. There are two different methods for processing fruit. One is a wet process, where the pulp is separated from the seeds, which are then fermented by soaking in water for about two days. This dissolves any pulp or sticky residue that may still remain on the seeds. The second process is a dry process in which branches and other foreign objects are separated from the fruit, which is then spread out in the sun for 2-3 weeks to dry.Coffee beans are green in colour before they are roasted and become dark brown. These green beans are rich in chlorogenic acid.