Valorisation of the Residues of Coffee Agro-industry: Perspectives and Limitations

Abstract

Abstract:Over ten million tonnes of solid residues are generated yearly from coffee agro-industry worldwide, along with larger amounts of wastewaters and cultivation residues. Both wastewaters and solid residues, such as defective coffee beans and spent coffee grounds, along with coffee husks (pulp and mucilage) that constitute around 60% of the wet weight of the fresh fruit, represent a relevant source of pollution and environmental threat, particularly from the widely adopted wet processing of coffee berries. Several attempts have been done to re-use the coffee processing solid residues, which include direct use as fuel in farms, animal feed, fermentation studies, adsorption studies, biodiesel production, briquetting, pelletizing, tannin extraction and production of specialty commodities. For the re-use of wastewaters, biogas production and direct delivery on plantations have been proposed or adopted, along with the treatment through infiltration, irrigation or (anaerobic) lagooning, reed bed and aerobic lagooning. In this study, the possible alternatives for the re-use and valorisation of the coffee processing and plantation are critically reviewed, taking into account the experiences with other agro-industrial residues and wastewaters, in the frame of a sustainable agro-industrial development.

The Solid Wastes of Coffee Production and of Olive Oil Extraction: Management Perspectives in Rural Areas

“…Various attempts have been made to circumvent these environmental problems and minimize the toxicity levels, e.g. improving production systems, reducing the volume of wastewater or recycling wastes to obtain value-added compounds such as enzymes and caffeine [1]. Out of the alternatives, only a few have been implemented in rural areas because of the costs and unavailability of the technology in these small communities.…”

“…The rural areas where coffee is cultivated are located mainly in the equatorial and sub-equatorial zone in Africa, Asia and South America. The top ten producing countries are Guatemala (224,871 tonnes/year), Mexico (257,940), Uganda (314,489), Honduras (380,296), India (385,786), Ethiopia (423,287), Indonesia (814,629), Colombia (892,871), Vietnam (1,818,811) and Brazil (2,859,502) [1]. Coffee production and processing, the latter step often taking place in locations distant from the beans production sites, generate yearly over 20 million tonnes of liquid and solid waste to be disposed of by farmers and processing plants.…”

“…In general, we can assume that coffee farm economics is dependent upon a wide variety of factors, including productivity, quality, costs of production and waste disposal, price premiums, the latter to achieve quality or sustainability standards. The options for the valorization of the coffee residues, not focusing on waste management in rural areas, have been recently reviewed [1,[3][4][5][6].…”

Composting and co-composting of coffee husk and pulp with source-separated municipal solid waste: a breakthrough in valorization of coffee waste

“…The environmental impacts of coffee production and processing are vast, with large quantities of solid and liquid wastes generated globally (Hue et al 2006). Over 10 million tonnes of solid residues are generated yearly from the coffee agro-industry worldwide, along with large amount of wastewater and cultivation residues (Echeverria and Nuti 2017).…”

Coffee pulp supplementation prior to breeding improves oxidative status without affecting fertility of primiparous ewes

“…Around 10 million tons of coffee residues are generated in the main producing countries (Echeverria and Nuti, 2017). Several studies have been conducted with the aim of using this residue in animal feeding (Lima de Souza et al, 2010;Salinas-Rios et al, 2015).…”