banana - Is the most well known and eaten (tropical) fruit. In eastern africa you can buy banana beer. This beer is brewed from bananas. Tropical fruit is usually picked unripe and has to ripen in the land of arrival.To make this process go faster bananas are treated with ethylene-gas.Normal bananas also ripen through ethylene-gas but exposing it to additional gas accelerates the process. Bananas are a good source of fiber,potassium adn vitamin c.