Olive Oil: Types, Properties, and Methods for Identifying Pure Olive Oil

As a dietitian, I place great emphasis on the quality and type of fats we use in our diet. Olive oil stands out as a crucial component of a healthy eating plan. However, understanding quality and purity when selecting olive oil is critical. In this article, I will discuss the types of olive oil, their properties, and how to identify genuine, pure olive oil.

Types of Olive Oil

Olive oil is categorized into various types based on different production methods and contents. Here are the most common types of olive oil:

1. Extra Virgin Olive Oil: This is the highest quality type of olive oil. It is obtained entirely through natural methods and undergoes no chemical processing. Its acidity level is below 0.8%, making it the purest and most flavorful olive oil. It is typically ideal for use in salads, cold dishes, and directly on the table.
2. Virgin Olive Oil: This oil is close in quality to extra virgin olive oil and is also unprocessed by chemicals. However, its acidity level ranges between 0.8% and 2.0%. While not as superior as extra virgin, it still retains beneficial health components and has a wide range of uses in the kitchen.
3. Refined Olive Oil: This oil is derived from olive oil whose acidic content has been reduced through chemical and/or physical processes. It generally has a lighter taste and aroma. It is suitable for cooking and frying, but its health benefits are more limited compared to natural olive oil.
4. Olive Pomace Oil: This oil is produced by blending refined olive oil with a small amount of virgin olive oil. Its acidity level ranges between 1-2%. Due to its mild flavor, it is particularly preferred for cooking.

Properties of Olive Oil

Olive oil is a nutrient rich in healthy fatty acids, antioxidants, and other bioactive compounds. Here are some key properties of olive oil:

1. High Antioxidant Content: Olive oil contains powerful antioxidants such as polyphenols and vitamin E. These substances protect the body from the harmful effects of free radicals and provide protection against chronic diseases like heart disease and cancer.
2. Monounsaturated Fatty Acids: A significant portion of olive oil consists of monounsaturated fatty acids like oleic acid. These fatty acids support heart health, lower bad cholesterol (LDL), and increase good cholesterol (HDL).
3. Anti-inflammatory Properties: Compounds like oleocanthal in olive oil have anti-inflammatory effects in the body. This makes olive oil an important part of an anti-inflammatory diet.
4. Flavor and Aroma: Extra virgin olive oil has a distinctive aroma and taste. This not only enhances the flavor of dishes but also highlights olive oil as a natural seasoning.

Methods for Identifying Pure Olive Oil

Unfortunately, the olive oil market is also rife with adulteration and low-quality products. Here are some tips I can offer to help you identify genuine and pure olive oil:

1. Label Information: The label on olive oil provides important information such as the type of oil, acidity level, production location, and date. Extra virgin olive oil generally has an acidity level below 0.8%. Additionally, the production date is crucial for freshness; olive oil offers the best quality when consumed within the first 1-2 years after production.
2. Taste and Smell: Pure olive oil has a fresh, fruity aroma. When you taste it, it may leave a slight peppery sensation on your tongue, which indicates a high polyphenol content. There should be no bitter or rancid taste.
3. Color and Consistency: Olive oil is usually golden yellow or greenish in color, though this can vary depending on the type of olive and harvest time. Its consistency should be slightly dense at room temperature. However, color is not always an indicator of quality; it’s better to consider taste and aroma.
4. Glass Bottle and Storage Conditions: Olive oil can deteriorate when exposed to light and air. Therefore, quality olive oil is typically stored in dark glass bottles. Once opened, it should be kept in a cool, dark place.
5. Cold Storage Test: Pure olive oil may partially solidify or crystallize when stored in the refrigerator. This is a sign that the oil is pure. However, this test is not definitive; the oil not solidifying does not necessarily mean it is not pure.

Conclusion

Olive oil is more than just an indispensable part of our kitchens; it is also of great importance to our health. As a dietitian, I believe that consuming olive oil in its highest quality and purest form is one of the cornerstones of a healthy lifestyle. Choosing and using olive oil correctly provides great benefits both in terms of flavor and nutrition. Therefore, it is essential to pay attention to quality, purity, and proper storage conditions when purchasing olive oil.

Dyt. Aysu Bozbaş
Dietitian and Nutrition Specialist