Brewing conditions impact on the composition and characteristics of cold brew Arabica and Robusta coffee beverages

Abstract

Cold brew coffee preparation is characterized by the use of long extracting periods and low temperatures; however, there are no reports in the literature on the influence of coffee species and preparation conditions during the cold extraction of the beverage. Thus the objective of this study was to evaluate the effect of coffee particle size (coarser and finer grind), water temperature (5 and 15 °C), and infusion time (up to 25 h) on the composition and characteristics of cold brew beverages prepared with Arabica and Robusta coffees. The main extraction of compounds occurred in the first 3–5 h of infusion. Compounds extraction behavior was distinct between different matrices, mainly considering the effect of coffee particle size. Arabica cold brews had a lower content of total chlorogenic acids (CGA) and caffeine and lower antioxidant activity (estimated by reducing capacity and ABTS radical scavenging activity) compared to Robusta cold brews, regardless of the coffee particle size or infusion temperature used. In general, to get cold brews with higher bioactive compounds extraction (CGA, caffeine, and melanoidins) and higher antioxidant activity and acidity, the use of low water temperatures and coarser grind coffee should be avoided.