Towards the sustainable and circular bioeconomy: Insights on spent coffee grounds valorization

Albuquerque

et al. 2023

IJERPH

Roasting is responsible for imparting the main characteristics to coffee, but the high temperatures used in the process can lead to the formation of several potentially toxic substances. Among them, polycyclic aromatic hydrocarbons, acrylamide, furan and its derivative compounds, α-dicarbonyls and advanced glycation end products, 4-methylimidazole, and chloropropanols stand out. The objective of this review is to present a current and comprehensive overview of the chemical contaminants formed during coffee roasting, including a discussion of mitigation strategies reported in the literature to decrease the concentration of these toxicants. Although the formation of the contaminants occurs during the roasting step, knowledge of the coffee production chain as a whole is important to understand the main variables that will impact their concentrations in the different coffee products. The precursors and routes of formation are generally different for each contaminant, and the formed concentrations can be quite high for some substances. In addition, the study highlights several mitigation strategies related to decreasing the concentration of precursors, modifying process conditions and eliminating/degrading the formed contaminant. Many of these strategies show promising results, but there are still challenges to be overcome, since little information is available about advantages and disadvantages in relation to aspects such as costs, potential for application on an industrial scale and impacts on sensory properties.

Section: Coffeementioning

confidence: 99%

Thermal Contaminants in Coffee Induced by Roasting: A Review

Albuquerque

et al. 2023

IJERPH

“…Moreover, using SCGs as a renewable energy source is relevant for mitigating environmental and climate issues (Gebreeyessus, 2022). The inadequate disposal of SCGs can cause eutrophication of water bodies due to the high organic matter content (Thenepalli et al, 2017).…”

Section: Brazil's Electricity Contextmentioning

confidence: 99%

Exploring Spent Coffee Grounds Energy Potential in the Brazilian Scenario

et al. 2023

Coffee stands out worldwide for being widely traded and consumed. However, this consumption generates a large amount of spent coffee grounds (SCGs) that are typically arbitrarily discarded. This biomass has a high heating value and molecular composition that allows for it to be a raw material for generating heat and energy. The search for renewable energy sources should consider the potential of SCGs. Thus, the objective of this study was to estimate the energy potential of SCGs in Brazil. The methodology consisted of searching for data to represent the generation of SCGs in the country and estimate its energy potential. It was found that the amount of SCGs available for power generation through direct combustion was approximately one thousand tons, and the power generation potential was 6.83 TWh/year in Brazil. This energy is sufficient to meet, for example, the total annual demand for public lighting in the country's Southeast. These results are the first steps towards evaluating the potential use of SCGs as an energy source and its environmental benefits. Additionally, this study explored limitations and barriers, providing valuable information for developing routes for using this energy residue and incentives for public policies.

“…Coffee consumption represents a well-established market, with a global daily consumption of around 3 billion cups . Waste generation and environmental impact are significant concerns, particularly regarding spent coffee grounds (SCGs), packaging materials, and single-use coffee pods. , As SCGs can potentially become environmental pollutants, SCGs byproducts can be valorized by collecting and recycling them, i.e., as food and drug ingredients, in bioenergy recovery, for compost and fertilizers, and as secondary raw material. , Valorizing SCGs aligns with the concepts of circular economy and bioeconomy for value retention of resource flows. Circular economy addresses global challenges, such as climate change, biodiversity loss, and pollution, through waste elimination, product and material circulation, and nature regeneration .…”

Section: Introductionmentioning

confidence: 99%

PLA Feedstock Filled with Spent Coffee Grounds for New Product Applications with Large-Format Material Extrusion Additive Manufacturing

Paramatti,

Romani,

Pugliese

et al. 2024

ACS Omega

Food waste and loss generate significant waste such as spent coffee grounds (SCGs) from coffee consumption. These byproducts can be valorized by following circular economy and bioeconomy principles, e.g., using SCGs in polymer-based composites for 3D printing. Although desktop-size material extrusion additive manufacturing is increasingly adopted for biomass-polymer-based composites, the potential of large-format direct extrusion 3D printing systems remains unexplored. This work investigated the thermal, rheological, and mechanical properties of PLA/SCG composites for applications with a largeformat pellet extrusion 3D printer. The formulations exhibit minimal degradation at typical 3D printing temperatures of PLA, i.e., ∼190 °C, and limited effects on crystallinity by increasing the SCG weight percentage. The decrease in viscosity due to SCGs improves the printability and layer adhesion, as confirmed by the tensile test results, such as higher ultimate tensile strength and elongation at break values compared to those of the state-of-the-art values. Using pellet feedstocks contributes to limiting the effects of thermomechanical degradation by reducing raw material processing, i.e., avoiding filament extrusion. Using PLA/SCGs formulations was demonstrated through 3D printed complex parts with nonplanar slicing techniques, including a large-scale furniture product, validating large-format pellet extrusion 3D printers for scaling up the use of biomass-filled polymers.