Pereira Joana, de Melo Marcelo M R, Silva Carlos M, Lemos Paulo C, Serafim Luísa S
CICECO-Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
LAQV-REQUIMTE, Department of Chemistry, Faculty of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
Bioengineering (Basel). 2022 Aug 3;9(8):362. doi: 10.3390/bioengineering9080362.
Acidogenic fermentation (AF) is often applied to wastes to produce short-chain organic acids (SCOAs)-molecules with applications in many industries. Spent coffee grounds (SCGs) are a residue from the coffee industry that is rich in carbohydrates, having the potential to be valorized by this process. However, given the recalcitrant nature of this waste, the addition of a pretreatment step can significantly improve AF. In this work, several pretreatment strategies were applied to SCGs (acidic hydrolysis, basic hydrolysis, hydrothermal, microwave, ultrasounds, and supercritical CO extraction), evaluated in terms of sugar and inhibitors release, and used in AF. Despite the low yields of sugar extracted, almost all pretreatments increased SCOAs production. Milder extraction conditions also resulted in lower concentrations of inhibitory compounds and, consequently, in a higher concentration of SCOAs. The best results were obtained with acidic hydrolysis of 5%, leading to a production of 1.33 gSCOAs/L, an increase of 185% compared with untreated SCGs.
产酸发酵（AF）常用于处理废弃物以生产短链有机酸（SCOAs），这些分子在许多行业都有应用。咖啡渣（SCGs）是咖啡行业的一种残留物，富含碳水化合物，有潜力通过此过程实现价值提升。然而，鉴于这种废弃物的难降解性，添加预处理步骤可显著改善产酸发酵。在这项工作中，对咖啡渣应用了几种预处理策略（酸性水解、碱性水解、水热法、微波法、超声法和超临界CO₂萃取），并根据糖和抑制剂的释放情况进行评估，然后用于产酸发酵。尽管提取的糖产量较低，但几乎所有预处理都提高了短链有机酸的产量。较温和的提取条件也导致抑制性化合物浓度较低，因此短链有机酸的浓度较高。5%的酸性水解取得了最佳结果，产酸量为1.33 gSCOAs/L，与未处理的咖啡渣相比增加了185%。
