Review on Post-harvest and Green Bean Coffee Processing in Ethiopia

摘要

Coffee (Coffea Arabica L.) is the major source of currency for Ethiopia and contributes more than 35% of the total export earnings. It is originated in Ethiopia. Coffee belongs to the family Rubiacea and the genus Coffea. The two main species of Coffee cultivated on a world scale are Arabica Coffee (Coffea arabica L.) and Robusta Coffee (Coffea canaphora L.), which account for about 98-99% of the world Coffee production. Even if the high production potential and economic importance of Coffee production and productivity of crop is still limited due to post-harvest handling and processing problems. Coffee processing is aimed to lower the water content of fresh cherries to a level which allows the preservation of beans (about 11-12 %), removing all the covering which surround the beans and preparing the beans according to market requirements. Unintentional or intentional harvesting of cherries at several stages of maturation may have adverse impacts on coffee quality if these materials are processed together. Cherries at different stages of maturation should be separated and processed using different techniques in order to retain as much quality as possible. Cherries must undergo dry, semi-dry or wet processing as soon as possible after harvesting. The storage of fresh cherries in bags, heaps, hoppers or silos should not last more than eight hours. Otherwise unwanted fermentation will generate the dreaded “stinker” beans, which appear when the temperature before pulping exceeds 40-42°C. Even if the temperature does not rise to the point of creating stinkers, uncontrolled fermentation may have other negative impacts on the cup. Coffee cherries should not be kept in plastic bags. The damp airtight atmosphere that develops inside plastic bags favors unwanted fermentation that damages coffee quality. Therefore, the main objective of this paper is to review on post-harvest and green bean coffee processing in Ethiopian.