Why Should We Be Concerned with the Use of Spent Coffee Grounds as an Organic Amendment of Soils? A Narrative Review
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Pérez Burillo, Sergio; Cervera Mata, Ana Gloria; Fernández Arteaga, Alejandro; Pastoriza de la Cueva, Silvia; Rufián Henares, José Ángel; Delgado Calvo-Flores, GabrielEditorial
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Residue Coffee Re-utilization Organic amendment Biofortification Soil quality
Date
2022-11-07Referencia bibliográfica
Pérez-Burillo, S... [et al.]. Why Should We Be Concerned with the Use of Spent Coffee Grounds as an Organic Amendment of Soils? A Narrative Review. Agronomy 2022, 12, 2771. [https://doi.org/10.3390/agronomy12112771]
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Andalusian Ministry of Economic Transformation, Knowledge Industry and Universities PY20_00585; Plan Propio de Investigacion y Transferencia of the University of Granada under the program "Intensificacion de la Investigacion, modalidad B"Abstract
Spent coffee grounds (SCG) are produced in massive amounts throughout the world as a bio-residue from coffee brewing. However, SCG are rich in carbohydrates, proteins, lipids, bioactive compounds and melanoidins, which are macromolecules with chelating properties. Additionally, SCG have showed potential applications in several fields such as biotechnology (bioethanol, volatile aromatic compounds, carotenoids, fungi and enzymes), energy production (combustion, pyrolysis, torrefaction, gasification, hydrothermal carbonization) and environmental sciences (composting). This review will focus on the last of these applications. SCG improve soil quality by increasing their chemical, physicochemical, physical properties and biological fertility. However, SCG inhibit plant growth at very low concentrations (1%) due to i. the stimulation of microbial growth and consequent competition for soil nitrogen between soil microorganisms and plant roots; ii. the presence of phytotoxic compounds in SCG, such as polyphenols. The SCG transformations that have proven to eliminate these compounds are vermicomposting and pyrolysis at 400 degrees C. However, it has been pointed out by some studies that these compounds are responsible for the chelating properties of SCG, which makes their elimination not recommended. The use of SCG as biochelates has also been studied, generating a residue-micronutrient mixture for the biofortification of edible plants.