Effect of preparation method and roasting temperature on total polyphenol content in coffee beverages

We evaluated the differences in total polyphenol content (TPC) of beverages prepared by three methods (Hario V60, espresso and pour-over coffee) using single-origin beans roasted at four temperatures. The beans were roasted based on the degree of roasting: the lightest roasting had a final temperature of 204 C (first roasting), a slightly darker roasting had a final temperature of 205 C (second roasting), a dark roasting had a final temperature of 215 C (third roasting) and the darkest roasting had a final temperature of 220 C (fourth roasting). TPC in the beverage was highest for the Hario V60 for all temperatures, ranging from 32.0 to 46.8 mg GAE g -1 (gallic acid equivalent per 1 g of ground beans). The third roasting had the highest TPC, ranging from 34.6 to 46.8 mg GAE g -1 for all methods of preparation, whereas the content for the fourth roasting ranged from 28.6 to 32.3 mg GAE g -1 . Our results indicated that the differences in TPC in the beverage depended on the preparation method (P < 0.001) and the degree of roasting (P < 0.001). The most nutritional coffee was prepared using the Hario V60 with the third roasting.