Robusta is easier to care for and has a greater crop yield than "C. arabica", so is cheaper to produce. Roasted robusta beans produce a strong, full-bodied coffee with a distinctive earthy flavour, but usually with more bitterness than arabica due to its pyrazine content. Since arabica beans are believed to have smoother taste with more acidity and a richer flavour, they are often considered superior, while the harsher robusta beans are mostly used as a filler in lower-grade coffee blends. However, the powerful flavour can be desirable in a blend to give it perceived "strength" and "finish", noticeably in Italian coffee culture. Good-quality robusta beans are used in traditional Italian espresso blends, at about 10–15%, to provide a full-bodied taste and a better foam head (known as "crema"). It is besides used as a stimulant, diuretic, antioxidant, antipyretic and relieves spasmodic asthma.