109 學年度學測英文 第 50 題

Probably the most widely used oil in cooking, olive oil is made by crushing olives with stone or steel blades to release the oil. Extra virgin oil, the finest grade, is made from the first pressing of the olives and has a very low acidity rate (under 1%). To be qualified as “extra virgin,” the oil must also pass both an official test in a laboratory and a sensory evaluation by a trained tasting panel. It must be free from impurity, while exhibiting some fruitiness and creating a pleasant bitter flavor along with a peppery sensation in the mouth. Second on the ranking is virgin olive oil. It is also a first pressing, but has a slightly higher acidity level (under 2%). Lastly, pure olive oil is the cheapest olive oil. It is refined to remove its impurities and blended to improve flavor, and is recommended for all-purpose cooking.

Packaging and storage also have an impact on the quality of olive oil. Olive oil spoils quickly when exposed to direct sunlight, so it should be stored in the dark at 16-18°C. Moisture and oxygen promote oxidation and therefore limit its shelf life. Plastic containers usually do not provide adequate protection from light, heat, or moisture; additionally, small particles in plastics can leak into the oil, which further reduces its quality.

Olive oil tasters have long adopted descriptive terms such as “pure” and “light” to evaluate the quality of olive oil. Recently, however, the International Olive Council (IOC) is seeking input on test methods to improve the transparency of the testing process and boost the accuracy of the results. A redefinition of the term “olive oil” is also proposed to make a clear distinction between virgin olive oil and pure olive oil. Industry members of the IOC hope to promote the trade of olive oil by initiating these changes.