Vegetable fats and oils

A vegetable oil is a triglyceride extracted from a plant. The term "vegetable oil" can be narrowly defined as referring only to plant oils that are liquid at room temperature, or broadly defined without regard to a substance's state of matter at a given temperature. For this reason, vegetable oils that are solid at room temperature are sometimes called vegetable fats. In contrast to these triglycerides, vegetable waxes lack glycerin in their structure. Although many plant parts may yield oil, in commercial practice, oil is extracted primarily from seeds.

On food packaging, the term "vegetable oil" is often used in ingredients lists instead of specifying the exact plant being used, especially when the oil used is less desirable to the consumer or if a mix is used.

Oils extracted from plants have been used since ancient times and in many cultures. As an example, in a 4,000-year-old kitchen unearthed in Indiana's Charlestown State Park, archaeologist Bob McCullough of Indiana University-Purdue University Fort Wayne found evidence that natives used large slabs of rock to crush hickory nuts, then boiled them in water to extract the oil. Archaeological evidence shows that olives were turned into olive oil by 6000 BC and 4500 BC in present-day Israel and Palestine.

Many vegetable oils are consumed directly, or indirectly as ingredients in food – a role that they share with some animal fats, including butter, ghee, lard, and Schmaltz. The oils serve a number of purposes in this role:

Secondly, oils can be heated and used to cook other foods. Oils suitable for this objective must have a high flash point. Such oils include the major cooking oils – soybean, rapeseed, canola, sunflower, safflower, peanut, cottonseed, etc. Tropical oils, such as coconut, palm, and rice bran oils, are particularly valued in Asian cultures for high-temperature cooking, because of their unusually high flash points.

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