Coffee by-products derived resources. A review

Coffee is the most common beverage and there are two main different methods to process coffee cherries. Coffee husk is the main by-product of coffee processing by dry method and is available in large quantities throughout the years, but its main application has been limited to animal feeding or energy production. Most of the coffee husk is disposed in landfills or arable land, usually with no care of its fate and changes to the source of pollution, especially in developing countries. Coffee husk can have several re-uses, but it is important to have environment-friendly methods to change it into useable material or material to be recycled in nature because of its important content of organic matter, chemical nutrients, and secondary compounds. The aim of this review is to recollect the amounts and uses of the coffee industry by-products, giving emphasis to its transformation into compost because of their large content of nutrients and the need to introduce high valuable organics into the soil.