Additionally, the authors thank Nicholas Walker for the English review. “
“Coffee is the most consumed food product in the world. Roasting induces severe transformation on coffee’s chemical composition. Additionally, during storage, the roasted beans are susceptible to further chemical and physical changes that may greatly affect the quality and the acceptability of the brew.

Lipids are major coffee components and correspond to approximately 11–20 g/100 g of roasted Coffea arabica composition ( Oliveira, Franca, Mendonça, & Barros-Junior, 2006; Toci, Farah, & Trugo, 2006; Trugo, 2003). Furthermore, triacylglycerols (TAG) comprise the main lipid class in coffee and account for approximately Selleck PD0332991 8–17 g/100 g (75% of total coffee lipids) in freshly brewed coffee, whereas free fatty acids (FFA) account for 0.1–0.2 g/100 g (about 1% of total coffee lipids Metformin only) ( Trugo, 2003). Among the most important unsaturated fatty acids for coffee freshness are oleic (18:1n-9), linoleic (18:2n-6) and linolenic (18:3n-3) acids, which account, respectively, for approximately 0.6–1.1 g/100 g, 2.9–5.4 g/100 g and 0.08–0.15 g/100 g, representing 7%, 36% and 1% of TAG fraction

( Folstar, 1985; Lercker et al., 1996; Nikolova-Damyanova, Velikova, & Jham, 1998; Speer & Kolling-Speer, 2006). Lipids may contribute to loss of sensory quality during storage. TAG can be hydrolyzed either chemically or enzymatically to produce a mixture of diacylglycerols,

monoacylglycerols, FFA, and glycerols molecules (Folstar, 1985; Frankel, 2005). The rate at which these reactions occur depends mostly on factors related to environmental and technological aspects such Thalidomide as availability of oxygen and moisture, exposed surface area, temperature, as well as package material (Manzocco & Lagazio, 2009; Pérez-Martínez, Sopelana, Paz de Peña, & Cid, 2008; Speer & Kolling-Speer, 2006). Since during coffee roasting hydrolytic enzymes are thermally inactivated, moisture and temperature are the main factors that will rule hydrolysis reactions in roasted coffee. The presence of high moisture content in food storage systems reduces the contact between food and oxygen, which tends to cause a decrease in oxidation reactions, but promotes hydrolysis reactions. When moisture in the storage system is low, Entropy decreases in the system, which leads to a decrease in the kinetic energy of the molecules and thus in the rates of all types of reactions. However, when storage temperature is high, Entropy increases, accompanied by a raise in the rate of degradation reactions (Frankel, 2005, Chapter 11; Kim & Min, 2008).