Chlorogenic acids, sensory quality and their relationship in global Geisha coffees

The chlorogenic acid (CGA) profile in Geisha green and roasted coffee beans from different sources and their correlation with sensory quality were studied. A total of 27 Geisha samples from global regions were collected (including four post-harvest processing methods: washed, natural, honey, and anaerobic fermentation). Sensory quality is evaluated through the Cup of Excellence cupping test. The qualitative and quantitative analysis of CGAs in coffee beans is conducted using high-performance liquid chromatography. The results showed that anaerobic fermentation Geisha had significantly higher sensory quality (total score: 88.3) and the lowest total CGA content in green beans (63.4 mg/g). Light Roasting led to a 58.3% decrease in total CGA content. The contents of 4, 5-diCQA, 3-CQA, and 4-CQA may increase after roasting. Correlation analysis indicated that the contents of 3-CQA and 4-CQA in green beans were significantly negatively correlated with sensory scores. However, in roasted beans, sensory scores were positively related to monoCQAs (5-CQA, 3-CQA, 4-CQA) and negatively related to two diCQAs (3, 5-diCQA, 4, 5-diCQA). It is supposed that chlorogenic acids may exist in green coffee beans as a precursor of negative flavors for light-roasted Geisha. No evidence showed that monoCQAs in roasted coffee beans have a negative effect on Geisha sensory quality. High-level diCQAs in roasted coffee beans may reduce the sensory quality of Geisha coffee. This study may contribute to the specialty coffee and functional beverages.