How could coffee contribute to solve environmental and social challanges, for instance greenhouse gas reduction, providing food and job creation?Coffee waste recycling can help creating a sustainable agriculture. Applying an innovative low-waste technolgy, the waste generated from coffee production can be used in cities and coffee farms while less greenhouse gases emitted into the atmosphere.
Usually coffee is a quite wasteful consumer product, because during production, collection, processing, roasting and brewing of coffee, 99.8% of waste is thrown away. Approximately 12 million tons of waste from agriculture in general is left to rot, generating methane gas (CH4) in millions of tons. Methane contributes to greenhouse effect and climate change, and it is 26 times stronger greenhouse gas than carbon-dioxide.
On the other hand agricultural waste from coffee production can be used for growing various species of mushrooms. In case of recycling methane emission can be prevented.
Demand for mushrooms in the world, mainly some tropical varieties such as ganoderma, shiitake, maietake growth for decades. However in US in 2012-2013 the overall mushroom production decreased and the value of mushrooms increased.
Generally mushroom-farming requires bacterial control at high energy cost. On the farm during fermentation, to peal the husks off beans, and through the exposure of ground beans to hot water when brewing a cup, bacteria are reduced to quite a low level permitting the mushrooms to digest fibers. It allows farming mushrooms on coffee. Tihs process is 80 percent more energy efficient on coffee than a conservative technology which prepares substrates for fungi farming and requires a considerable amount of energy while contributes to climate change.
Shiitake and ganoderma are farmed on hardwoods. Hardwood trees, like oak generally are harvested, ground and converted into artificial logs. Usually it takes up to 9 months to fruit mushrooms. By-products from coffee, for example prunings, husks, pulp and grounds are also a type of hardwood. This by-product matrix stimulates the growth of mycelium and mushrooms appear very quickly 3 months after seeding.
There are many other environmentally friendly technologies to convert the methane-generating biomass from coffee production to row material in a low-waste technology avoiding methane emission.
According to a study (Pujol et al.) which analysed the chemical composition of exhausted coffee waste generated in a soluble coffee industry, the exhausted coffee wastes showed characteristics for various potential applications such as biodiesel production, as a source of antioxidants and as a biosorbent of hydrophobic pollutants. It was proved by Al-Zaben and Mekhamer that coffee waste can remove 4-chloro-2-methyl phenoxy acetic acid (MCPA) from aqueous solutions
The use of coffee husks from agroindustries is very economical for the production of mosquito pathogenic bacilli. A new study (Poophati and Many) is important from the perspective of recycling of coffee waste because it possesses the dual benefits of effective use of environmental bioorganic waste and efficient production of mosquitocidal biopesticides.
Coffee waste recycling is a promising environmental friendly technology which can contribute to environmental sustainability.
S. Poopathi, C. Mani: Coffee in Health and Disease Prevention, Chapter 32 – Use of Coffee Husk Waste for Production of Biopesticides for Mosquito Control, 2015, Pages 293-300
D. Pujol, C. Liu, J. Gominho, M.À. Olivella, N. Fiol, I. Villaescusa, H. Pereira : The chemical composition of exhausted coffee waste, Industrial Crops and Products, Volume 50, October 2013, Pages 423-429
L. S. Oliveira, A. S. Franca: Coffee in Health and Disease Prevention, Chapter 31 – An Overview of the Potential Uses for Coffee Husks, 2015, Pages 283-291
G.Pauli: Coffee : Export Crop Provides Food Security, 2010, kekgazdasag.hu
S. Hoyle , Mushrooms profile, Agricultural Marketing Resource Center, March 2014 http://www.agmrc.org/commodities__products/specialty_crops/mushrooms-profile/