Olive oil contains powerful polyphenols that may reduce inflammation and disease risk.This study suggests adding EVOO to veggie patties may increase nutritional value.Air-frying and baking showed better nutrition and sensory attributes compared to deep frying.

Olive oil is considered nutritional liquid gold to many. Its plant compounds, including monounsaturated fats (MUFAs) and antioxidants, can help support your overall health, and they may even reduce inflammation and cancer risk. 

Olive oil’s low smoke point—the temperature at which oil begins to smoke and lose its nutritional value and flavor—means that there may be some caveats when it comes to cooking with olive oil. To help add more evidence to the conversation, Chilean researchers recently compared the nutritional composition of veggie patties with and without added extra-virgin olive oil (EVOO), cooked using three different methods.

They also performed a blind taste test with 53 participants to see which patty they preferred based on several characteristics. They published their findings in Foods. Let’s break down what they found.

How Was This Study Conducted?

This study was done in two parts. For the first part, researchers made veggie patties that contained broccoli, carrots, onion, egg white, oat flour, salt, pepper, garlic powder and cumin. In half the patties, they added about half a teaspoon of EVOO during preparation as part of the recipe.

Each type of patty—both those with and without EVOO—was then cooked using various cooking methods: deep frying, air frying and baking. Nutritional values were measured in raw samples of the patties and in each cooked patty to compare nutrient gain or loss to the raw sample.

The second part of this study was a blind taste test. For this part, 53 participants were recruited from a university campus. The tasting panel consisted mostly of women (77%), with 40% of them being young adults ages 18 to 20. Participants were given samples of each of the patties but were not told which ones contained EVOO or what cooking method was used. They rated each sample’s sensory attributes, including taste, texture, aroma and appearance, on a scale of one to seven, one being “dislike very much” and seven being “like very much.”

What Did This Study Find?

After the analyses were performed, a clear winner emerged in both nutritional value and sensory appeal. Patties enriched with EVOO that were air-fried ranked highest overall, with EVOO-enriched baked patties coming in a close second. Both patties had higher MUFA levels, antioxidants and other nutrients compared to deep-fried patties.

The air-fried EVOO patties ranked the highest in all sensory attributes, while the baked EVOO patties were about equal to air-fried in taste, texture and aroma.

How Does This Apply to Real Life?

Olive oil is one of the rockstars in the Mediterranean diet. It’s great as a bread dipper, drizzled over veggies or in marinades and dressings. Cooking with olive oil is a bit controversial, though, as some early studies suggested that heating olive oil may negatively affect its nutritional value. However, more recent research suggests that while cooking with olive oil may reduce some of the beneficial compounds in it, the effect is negligible. As long as the cooking temperature is 375°F (olive oil’s smoke point) or less, olive oil retains most of its nutritional qualities. With that said, heating olive oil might affect its flavor, especially if heated above its smoke point.

Some of olive oil’s nutritional value depends on its quality, which in turn depends on several factors, including the type and health of the olives used, the time and method of harvest, the fertilizers used on the olive trees and the amount of time elapsed between harvest and pressing. These factors can also affect the price of olive oil, with higher-quality EVOOs tending to be higher in cost.

If you want to start using more olive oil in your recipes, go for the best EVOO that’s within your grocery budget—because while any olive oil is probably better than none, you want to get the most nutritional bang for your buck. When choosing your olive oil, look for:

Tinted bottles: The dark tinting helps block out light, and light increases degradation of the oil.Best-by date and/or harvest date: Ideally, olive oil is used within two years of bottling, though the closer to harvest and bottling, the better.Quality assurance seals: Quality assurance seals often indicate that the company producing the olive oil has agreed to random off-the-shelf compliance testing for international standards of quality and purity.

While buying olive oil in bulk might seem like a good idea, especially financially, this probably isn’t the best for most of us. Buy a bottle size that you’ll be able to use up within two or three months, since once opened, the quality starts to slowly degrade. You can slow the process down by storing it in a cool, dark place and using it up within the recommended timeframe.

If you’re ready to add more EVOO to your life and need some recipes to get started with, check out our salad dressings made with olive oil. They’re great drizzled over leafy green salads and roasted veggies or used as a marinade for chicken, beef or salmon. Our Olive Oil Braised Summer Squash is super easy, quick and delicious any time of the year.

Olive oil isn’t just for savory dishes, though. We use it in Apple-Honey Cake and Greek Walnut Spice Cake. And we love Jennifer Garner’s Lemon Olive Oil Cake recipe.

Of course, olive oil is a staple in the Mediterranean diet, and we’ve got lots of meal plans to choose from. If you’re just getting started, try our 7-Day Mediterranean Meal Plan for Beginners. Or if you’re battling the winter blues, give our 31-Day Mediterranean Diet Meal Plan for More Energy in January a whirl. Besides olive oil, it’s loaded with other nutrient- and antioxidant-rich foods and recipes that will help boost your mood and energy.

Our Expert Take

This study suggests that adding olive oil to veggie patties may increase their nutritional value. Participants ranked EVOO-enriched patties that had been air-fried and baked significantly higher in taste, texture, aroma and appearance compared to deep-frying. If you’d like to make your own veggie patties, our Mushroom-Quinoa Veggie Burgers with Special Sauce or Umami Veggie Burgers are good ones to start with. Feel free to add half a teaspoon of EVOO per patty when preparing them, as the researchers did in the study, for an extra boost of nutrition.

Dining and Cooking