Analysis of antioxidant profiles in cold-drip and hot-brew coffee

Coffee is the second most traded commodity in the world. With such a high popularity throughout the world, there have been many variations in the beverage. Cold-drip coffee is prepared by slowly filtering cold water through a bed of ground coffee. This study aims to identify differences in antioxidant profiles between coffee prepared through cold-drip and standard hot-brew methods. While specific studies have been undertaken on the antioxidant capacity of coffee, many were benchtop analyses with the inability to study individual compounds. In this study, taking advantage of post-column derivatisation in specially designed chromatography columns coupled with the cupric reducing antioxidant capacity (CUPRAC) assay, it was observed that there is indeed a difference in antioxidant profiles as a result of the method of preparation. Further, while many core components were similar between different preparation methods, cold-drip coffee yields a lower concentration of antioxidants than the same coffee prepared as a hot brew. The reproducibility and variation between different coffee brands were also explored.