Barberries are rich in vitamin C and have a sharp acid flavour. In Europe for many centuries the berries were used for culinary purposes in ways comparable to how citrus peel might be used. The country in which they are used the most, is Iran where they are referred to as "Zereshk" . The berries are common in Iranian (Persian) cuisine such as in rice pilafs (known as "Zereshk Polo") and as a flavouring for poultry meat. Due to their inherent sour flavor, they are sometimes cooked with sugar before being added to Persian rice.