The stable isotope ratio analysis of bulk oil allows the detection of the addition of C4 plant oil, such as maize oil, to other edible vegetable oils. Using compound specific carbon stable isotope ratio analysis, it is possible to identify other types of adulteration, such as the addition of pomace oil to virgin olive oil, or to distinguish different types of edible vegetable oil. Edible oils are lipid products that are typically liquids at room temperature whereas animal-derived fats tend to be more saturated and are therefore solid at room temperature. The chemical composition of vegetable edible oils is predominantly triacylglycerides of fatty acids mixed with minor quantities of other lipid. Edible vegetable oils are mainly derived from oily nuts and seeds but can also be obtained from other parts of a plant, such as flowering tops, leaves, flowers, fruits, roots, and rhizomes. Sesame oil is obtained from sesame seeds that are roasted before pressing.