Bomfim Anne Shayene Campos de, Oliveira Daniel Magalhães de, Voorwald Herman Jacobus Cornelis, Benini Kelly Cristina Coelho de Carvalho, Dumont Marie-Josée, Rodrigue Denis
Fatigue and Aeronautical Materials Research Group, Department of Materials and Technology, UNESP-São Paulo State University, Guaratinguetá 12516-410, São Paulo, Brazil.
Bioresource Engineering Department, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada.
Polymers (Basel). 2022 Jan 22;14(3):437. doi: 10.3390/polym14030437.
Spent coffee grounds (SCG) are a current subject in many works since coffee is the second most consumed beverage worldwide; however, coffee generates a high amount of waste (SCG) and can cause environmental problems if not discarded properly. Therefore, several studies on SCG valorization have been published, highlighting its waste as a valuable resource for different applications, such as biofuel, energy, biopolymer precursors, and composite production. This review provides an overview of the works using SCG as biopolymer precursors and for polymer composite production. SCG are rich in carbohydrates, lipids, proteins, and minerals. In particular, carbohydrates (polysaccharides) can be extracted and fermented to synthesize lactic acid, succinic acid, or polyhydroxyalkanoate (PHA). On the other hand, it is possible to extract the coffee oil and to synthesize PHA from lipids. Moreover, SCG have been successfully used as a filler for composite production using different polymer matrices. The results show the reasonable mechanical, thermal, and rheological properties of SCG to support their applications, from food packaging to the automotive industry.
用过的咖啡渣（SCG）是许多研究中的热门课题，因为咖啡是全球第二大消费饮品；然而，咖啡会产生大量废弃物（SCG），如果处理不当会引发环境问题。因此，已经发表了多项关于SCG价值化的研究，强调将其废弃物作为不同应用的宝贵资源，如生物燃料、能源、生物聚合物前体和复合材料生产。本综述概述了将SCG用作生物聚合物前体和用于聚合物复合材料生产的研究。SCG富含碳水化合物、脂质、蛋白质和矿物质。特别是，碳水化合物（多糖）可以被提取和发酵以合成乳酸、琥珀酸或聚羟基脂肪酸酯（PHA）。另一方面，可以提取咖啡油并从脂质中合成PHA。此外，SCG已成功用作使用不同聚合物基体的复合材料生产的填料。结果表明SCG具有合理的机械、热和流变性能，以支持其从食品包装到汽车工业等领域的应用。
