The following table summarizes the lipid fraction composition generally found in green coffee.
Lipids in Green Coffee:
In terms of quality, arabica contains almost 60% more lipids than robusta which may play an important role in aroma retention. In one study of Central American coffees it showed a direct correlation between lipid content and beverage quality by a panel of cupping experts.
Studies on coffee storage have also shown that fatty acid concentrations increase when coffee is stored for an extended period of time at subtropical temperatures. As a result, it is believed that decomposition of lipids during elevated temperate storage may lead to the formation of flavors in the coffee.
But interestingly during roasting lipids (as well as caffeine) remain virtually unchanged owing to their relatively high melting points.