What is a peroxide value of EVOO? What is the shelf life of EVOO? Answers to some of your EVOO questions!
Every week I will update this blog in response to questions I frequently get about The Furies and Extra Virgin Olive Oil. Feel free to email me with specific interests or questions. I love hearing from you!
What is a peroxide value of EVOO and what does it indicate?
Like acidity indexes, the peroxide value of extra virgin olive oil is a standard chemical analysis done to determine and validate the quality of the oil. The peroxide index is measured in milliequivalents of active oxygen per kilogram. Olive oil becomes oxidized when it encounters air, resulting in the formation of peroxide. A low peroxide level indicates a high quality EVOO. It is achieved by the extraction process during milling and the storage conditions of the oil immediately after the crush to packaging. Prior to packaging, it is important that olive oil gets stored in stainless steel tanks that are nitrogen flushed and temperature controlled, protecting the oil from light, heat, and oxygen. BPA free tin and dark glass have been shown to be the best packaging material to preserve EVOO quality and freshness.
The maximum peroxide value for extra virgin olive oil is 20. High peroxide levels indicate that oil has been damaged by free radicals and will give rise to aldehydes and ketones that can cause oil to smell musty and rancid. These reactions are accelerated by heat, light, and air. Like with levels of Free Fatty Acids, be wary of refined or blended olive oils. The refinement process uses heat and or chemicals to make oil odorless, tasteless, and colorless, removing all products susceptible to oxidation thereby eliminating peroxide levels. High quality EVOO should have a peroxide value below 12.
The Furies EVOO was tested with a result of 5.9. This is reflective of the freshness of our oil. This very low peroxide value means that it will be more stable and if stored correctly the shelf life will be extended. Oxidation is a natural process. It occurs more slowly, however, in Extra Virgin Olive Oils with the highest levels of oleic acid and polyphenols.
What do acidity levels tell you about your EVOO?
Acidity is a parameter of quality that cannot be detected by taste. The measurement of acidity in EVOO refers to the percentage of free fatty acids per 100 grams of oil. To be labeled as Extra Virgin Olive Oil the limit of free fatty acid is 0.8%. The best EVOOs have acidity levels less than 0.3%.
Olive oil consists of 99.9 percent fat, known as triglycerides. It is a healthy monounsaturated fat primarily composed on oleic acid. When olives are milled, the formation of free fatty acids occurs from the action of enzymes released in the presence of water. Hydrolysis happens as enzymes break some of the fatty acids off the triglycerides and they become free acids or free fatty acids.
The highest quality EVOO has the lowest levels of acidity. Free fatty acid speaks to the condition of the fruit at the time of crush. Levels of acidity increase when olives are damaged, bruised, overripe or heated during production. Increased acidity can also occur when there is a delay between harvest and crush, allowing fermentation. For olive oil to have the lowest levels of FFA, it must be made with the best quality olives, use entirely cold water, state of the art production processes, and handle the olives with the utmost care.
Be incredibly careful when purchasing olive oil. Acidity is only an index applied to virgin olive oils. It can be used as misleading marketing when shown on bottles of olive oil that are blended or refined, sometimes labeled as ‘light’ or ‘pure’. The refining process often takes poor quality oil and removes all free fatty acids by adding caustic soda that converts acids to soap that can be removed.
The Furies EVOO is tested at an independent laboratory at 0.18%. We have the very freshest, premium EVOO available! Use it liberally and Cook with a Vengeance!
Mueller, Tom. Extra Virginity: The Sublime and Scandalous World of Olive Oil. New York, W.W. Norton Co, Inc. 2012.
What is the shelf life of EVOO?
Discussion of acidity and peroxide testing of EVOO, leads naturally into the question of shelf life. We believe it is best to buy the highest quality olive oil and use it generously and quickly. After bottling, EVOO should be consumed withing 18-24 months. An opened can is best used within 1-2 months. We recommend buying a size that fits into this parameter. Proper storage of your EVOO helps to preserve its freshness. It is important to store EVOO away from light and heat. Try not to keep it directly next to the stove. Our tin cans are completely opaque so light will not penetrate, but direct sunlight may increase the internal temperature. The optimal storage temperature is between 60-72 degrees.
We chose BPA free tin canisters with these considerations in mind. Tin has been shown to be effective in preserving EVOO quality on par with dark glass. It is also lighter and experiences less breakage during shipment overseas. Fun fact: tin has been shown to be recycled more frequently than dark glass bottles.
Times have changed since EVOO was used sparingly or only on special occasions. We now know that cooking with EVOO brings out natural antioxidants and polyphenols in vegetables. So, use The Furies with confidence and Cook with a Vengeance!
What are polyphenols?
Polyphenols are phytonutrients found in plant foods, especially in extra virgin olive oil. Polyphenols are shown to have amazing health benefits. The olive tree produces multiple polyphenols including flavonols, lignans, and glycosides. The abundance of polyphenols in EVOO promotes health and longevity. They work to improve cholesterol balance, lower oxidative stress, and enhance the lining of blood vessels. This helps to decrease a person’s risk of cardiovascular disease and lower blood pressure. Phytonutrients act as antioxidants in the body to lower inflammation, strengthen the immune system, improve metabolism, stave off dementia and balance blood sugar levels. Olive polyphenols can also decrease angiogenesis, a process necessary for the spread of cancer cells.
Remember, these power phytonutrients remain when you cook with EVOO and can even heighten the naturally occurring polyphenols in the vegetables that you cook, doubling up on their antioxidant power! Also, quality matters. Careful handling of the olives during harvest, same day milling, young olives, cold water extraction, and first press unfiltered contribute to the highest levels of polyphenols and best quality EVOO. Reach for The Furies with confidence to empower your heath and awaken your food!
Why is The Furies unfiltered?
Because it is the healthiest and freshest EVOO! Unfiltered EVOO preserves additional polyphenols in the small amounts of water that is not removed during milling. Some of these nutrients get lost when oil is filtered. Polyphenols and antioxidants are the key to EVOO’s tremendous health benefits. Unfiltered EVOO is also produced during the early harvest when olives are smaller, greener, and most nutritious. Finally, unfiltered EVOO is often the freshest on the market. Always check for both ‘harvest date’ and ‘best before date’ when purchasing EVOO.
Can I cook with EVOO? Why should I use good EVOO to cook rather than regular olive oil?
Yes, you should most definitely cook with EVOO! EVOO is one of the most stable and healthiest ways to cook food. The myth surrounding the question of not using EVOO to cook has been solidly debunked with research. EVOO’s smoke point of 410’ F is well within normal sautéing temperatures. Cold extracted EVOO produces fewer carcinogens when heated when compared to refined oils. Good quality EVOO has the highest levels of antioxidants that has been shown to contribute to its stability when heated. Research has shown that nutritious polyphenols and antioxidants are not lost when heated thereby increasing the nutritional impact of your food.
Is The Furies EVOO Kosher?
Yes. The Furies EVOO is harvested and milled in small batches. It is never blended with any other EVOO. Our mill has been ISO 22000 certified for International Food Safety Standards. Olive oil is the sole product made onsite. The Furies is entirely cold extracted using state of the art equipment. It is Certified Organic.