Analysis of Caffeine and Antioxidant Content of Ethiopian Coffee Varieties from Different Growing Areas

Abstract

Quality coffee consumption is increasing nowadays; however, quality can only be achieved through appropriate cultivation and processing techniques. The study is aimed at using high-performance liquid chromatography (HPLC) and spectrophotometric techniques for evaluating different coffee varieties grown in Ethiopia based on caffeine, antioxidant, and polyphenol content. Despite coming from various coffee-growing regions, all of the tested coffee varieties (heirloom, forest coffee, heirloom 2, bourbon, mixed heirloom, and catuai) underwent wet processing. The data revealed that the caffeine content ranged from 0.14 to 0.37 mg/g, total antioxidant content from 63.75 to 78.05 mg AAE/g, and total polyphenol content from 27.08 to 31.04 mg GAE/g in the selected varieties. The findings show that the amount of the identified compounds is significantly ( $p\le 0.05$ ) influenced by the variety type, growing area, and processing (intensity of roasting). The different coffee varieties were also tested for sensory quality, and the findings suggest that the typical coffee drinker prefers fruity flavors in their coffee, along with medium acidity and roasting intensity levels. The cultivation and processing technologies used in coffee production have a significant impact on the quality and sensory enjoyment of coffee.