Particle size distribution influences on Espresso Coffee extraction.

Espresso coffee (EC) extraction depends with a great extent on coffee particle sizes produced by grinding, and also brewing process. To extract tempting aroma and taste in EC, the grinding process is a crucial step. The taste and flavor change in important manner owing to the particle size of ground coffee. This research aims at optimizing the impact of different particle size on aroma and bioactive compounds. In experimental part, quantitative and qualitative analyses were conducted on two cultivars: Arabica and Robusta [1]. The size of grinded coffee was between 200-400 and 400-1000 microns. EC extraction were in duplicate for each particle size samples with 12 and 14 grams of grinded coffee. The espresso machine settings are maintained at 9 bar and 92±2⁰C. Volatile compounds were divided into family groups and identified by using HS-SPME-GC/MS [2]. Results confirmed a good extraction efficiency of caffeine, which accounted for 170 mg (200-400 microns) and 90 mg per cup (400-1000 microns), respectively. References [1] Caprioli G, Cortese M, Cristalli G, Maggi F, Odello L, Ricciutelli M, Sagratini G, Sirocchi V, Tomassoni G, Vittori S. Optimization of espresso machine parameters through the analysis of coffee odorants by HS-SPME-GC/MS. Food Chemistry. 2012;135(3):1127-1133. [2] Sanchez Lopez JA, Wellinger M, Gloess AN, Zimmermann R, Yeretzian C. Extraction kinetics of coffee aroma compounds using a semi-automatic machine: On-line analysis by PTR-ToF-MS. International Journal of Mass Spectrometry. 2016;xxx:xxx-xxx. [3] Folmer B, Blank I, Farah A, Giuliano P, Sandres D, Wille C. The Craft and Science of Coffee, London, UK: Elsevier, 2017.