Coffee: One of the Most Consumed Beverages in the World

Abstract From its legendary discovery in Abyssinia (today Ethiopia) to becoming one of the most consumed beverages in the world, coffee has captivated the enthusiasts for centuries due to its unique aroma and taste, as well as its effects as a stimulant in enhancing mental performance (e.g., alertness, concentration, attention). This article provides a brief overview on the production and processing of coffee, focusing on the Coffea arabica and Coffea canephora var. Robusta, also known as Arabica and Robusta, respectively. Differences in chemical compositions (e.g., lipid, sucrose, trigonelline, diterpenes, caffeine, chlorogenic acids) of bean variety contribute to desirable/undesirable sensory attributes, as well as the health implications of the final brew products. Roasting of green beans, which is typically carried out at 170–230 °C for 10–15 min, causes the degradations of polysaccharides, sugars, amino acids, chlorogenic acids, and so on. Concomitantly, a myriad of aroma volatiles and complex condensed products are formed, mainly due to Maillard reaction, Strecker degradation and pyrolytic reactions. The effects of roast time–temperature profiles on a number of key physicochemical phenomena are discussed, including changes in microstructural, formation of aroma species, development of color, and generation of CO2 during roasting. Optimal storage conditions and packaging are important in delaying product staling and to mitigate CO2 degassing issues. These aspects, along with other factors that affect the shelf-life of coffee, are discussed. Finally, a brief literature review on the health implications of coffee consumption is presented, highlighting the importance of several bioactive components (e.g., caffeine, chlorogenic acids, melanoidins, trigonelline, acrylamide, and diterpenes).