Abstract

This study aims to determine and obtain the total polyphenolic and caffeine content from coffee beans (Coffea arabica L) with some combination of factors. The extraction process was performed using natural deep eutectic solvent-based ultrasonic-assisted extraction (NADES–UAE) method with the different condition including extraction time, NADES ratio, and liquid-solid ratio. The total polyphenolic content was calculated using a microplate reader 96 well. The caffeine content was examined using high-performance liquid chromatography. Based on the results demonstrated the effect of different NADES components (namely lactic acid–sucrose and citric acid–glucose) on the total polyphenolic and caffeine content. The highest total polyphenolic content was 87.01 mg GAE/g sample (2 g/g lactic acid–sucrose ratio and 10 mL/g liquid-solid ratio for 15 minutes) and 62.91 mg GAE/g sample (5 g/g citric acid–glucose ratio and 15 mL/g liquid-solid ratio for 15 minutes). Whereas, the highest caffeine content was 4.45 mg/g (4 g/g lactic acid–sucrose and 15 mL/g liquid-solid ratio for 35 minutes) and 1.30 mg/g (2 g/g lactic acid–sucrose and 30 mL/g liquid-solid ratio for 5 minutes), respectively. These results were obtained the green extraction method with rapid, easy, inexpensive, and environmentally friendly.

Key words: Caffeine content, Coffea arabica L, natural deep eutectic solvent, total polyphenolic content, ultrasonic–assisted extraction