Fats that remain liquid at ambient temperatures. They can be extracted from seeds, nuts and fruit by crushing and pressing, or by using heat or chemicals. Cold–pressed oils and extra virgin olive oil tend to have the best flavour as the more refined oils lose their natural characteristics. Oils can be divided into three categories depending on which fatty acids they contain: saturated, monounsaturated or polyunsaturated. All vegetable oils are cholesterol–free as they are derived from plants.