Quality and Quantity of Organic Acid, Lipids and Acid Value Influence the Quality of Specialty Coffee

Abstract

　The quality of specialty coffee (SP) is evaluated based on the grading system (number of defects of green beans and sensory evaluation of roasted beans) of the Specialty Coffee Association of America, while the quality of commercial coffee (CO), which is a product with a wide variety of uses, is evaluated based on the export standards (number of defects and altitude) of its country of origin. Nevertheless, a physicochemical quality-based evaluation method has not yet been established. In this study, the pH, titratable acidity, organic acid content, total lipid content, and acid values of Kenyan, Guatemalan, and Columbian SP and CO samples were analyzed and evaluated to correlation with sensory scores to find new indicators for quality evaluation of coffee. Significant differences were shown to the pH and acid values of all SP samples, and in the titratable acidity and total lipid contents of some SP samples. In addition, the sensory evaluation scores for all the SP samples were more than 80, and were significantly higher than those for the CO samples. The significance of values obtained from the physicochemical analysis is reflected in the sensory evaluation scores, and it was suggested that they affect the coffee quality.