Coffee beans are produced and exported by more than 50 countries, however, most consumers are in industrialized countries such as the US, European Union and Japan.

Coffee beans are the second most traded product in the world and are of vital importance for the trade balance between developed and developing countries. It is one of the most widespread beverages in the world, giving the producing countries an average income of eight billion dollars / year.

Coffee Beans

According to COFFEA, in Brazil, the main coffee region covers the states of Minas Gerais, Espírito Santo, São Paulo and Paraná, with more than 90% of the national production. Historically, coffee produced in Brazil is destined for exports and domestic consumption.

One of the options in the coffee harvest is to harvest the fruits produced by the plant in different stages of maturation and separate them in a processing unit by cleaning, washing and peeling. For processing, there can be two forms: wet and dry processing.

Coffee Maturation Stages

Dry way

The humid processing of coffee drying is quite common among Central American and African producers, achieving good market prices for generally producing soft drink production.

Although Brazil is known as a producer of dry coffee beans (90% of its total production), it is well known that there is a tendency for producers to opt for this method, which adds value to the product according to the quality obtained from the beverage.

However, although humid processing offers numerous advantages, it generates large volumes of wastewater rich in organic materials highly polluting to the environment and human health, requiring prior treatment for discharge into watercourses. The conditions and standards for the launch are described in Resolution No. 430 of CONAMA.

Coffee Wastewater

Wet way

It consists in the use of water in the process of washing, separating and removing the bark (exocarp) and the mucilage (mesocarp), giving rise to the coffee peeled, pulped and demucilled. The pulping of the coffee consists in the removal of the bark of the ripe fruit by means of a mechanical peeler and subsequent fermentation of the mucilage and washing of the beans. Pulled coffees have the advantage of considerably decreasing the terreiro area (30%) and the time required for drying (1/3 of the dry process), in addition to generally providing soft drink production.

Pulpy Coffee

Reinforcing, ARCs are rich in organic and inorganic compounds and pollutants that cause degradation of soils, streams and air pollution by the emission of gases such as methane, carbon dioxide, hydrogen sulfide and ammonia, among others , as a result of bacterial activities.

Thus, technologies must be developed to reduce the expense of water in the processing of coffee fruits and / or methods for the removal of polluting organic products, so as not to compromise the sustainability of peeled coffee production.

Patricia Rodrigues Gonring

Student of Chemical Engineering, Federal University of Espírito Santo – Alegre, ES