Identify, use and dispose of rancid olive oils

High-quality olive oils give many dishes a special kick. Olive oils are liquid fats that, as flavor carriers, really bring out the aroma. However, if stored incorrectly, oils such as olive oil can also go rancid, which means that they will spoil and are therefore no longer edible. But how do you recognize rancid oil? Can rancid oil still be used? Or how do you properly dispose of the oil?

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— OLIVEOILSEASON (@oliveoilseason) October 14, 2021

How do you identify rancid olive oil?

There are two equally simple methods of identifying rancid oil. For the first method, the olive oil is heated and sniffed. The warmth makes the smells stand out better. Rancid oil smells a bit stale or even musty. The smell is unpleasant compared to fresh and good olive oil. Warming is a method that should be used before tasting by mouth, as the taste of rancid oil is even more objectionable than the smell.

The second method is about implemented by tasting a small amount by mouth. The taste of rancid oil is creamy, strange at first to unpleasant or even unbearable. This cannot be compared to the bitterness or fruity-fresh taste of fresh olive oil.

Once olive oil has gone rancid, it should no longer be used. Not only is the unpleasant taste very annoying and can spoil entire dishes, but health problems can also occur, since rancid olive oil can impede the metabolism due to the changed ingredients.

Is rancid oil harmful to health?

Besides Metabolic restrictions, rancid vegetable oil and thus olive oil can be harmful to health. According to a study in the Journal of Food and Nutrition Sciences, free radicals in rancid vegetable oil can contribute to cellular damage and diabetes.

Rancid oil forms harmful free radicals in the body that are known to cause cellular damage and with Diabetes, Alzheimer’s and other diseases.

Rancid oils can also cause digestive problems and deprive the body of vitamins B and E. For the sake of your health, you should definitely avoid rancid olive oil.

Why and how does oil become rancid?

Heat and light in particular are considered to be the influences that cause oxidation pump and let the oil go rancid. However, according to studies other aspects affect olive oil:

Rancidity is one of the main problems when using vegetable oils. Time, temperature, light, air, exposed surface, humidity, nitrogenous organic matter, and trace metals are known factors responsible for rancidity.

Oil becomes rancid because the The unsaturated fatty acids contained in the oil react with the oxygen in the air. This process is referred to as oxidizing. The contact of oxygen with the fatty acids leads to an exchange of molecules that reconnect. As a result, degradation products such as peroxides, alcohols, aldehydes and carboxylic acids are formed. In the chemical test, the peroxides in particular can be detected, the maximum value of which may be 20 for an extra virgin olive oil (EVOO). Values ​​above this are chemical proof of the rancidity of the oil.

How can I recognize rancid olive oil before buying?

It is impossible to determine rancidity before buying olive oils. However, if they are stored in containers without UV protection and have been exposed to temperatures above 22 °C for a long time, you should not buy them. If older oils, which can still be good if stored correctly, were bought, a smell and taste test can be carried out. If the oil is rancid, this is a reason for an exchange, which good dealers always do without any problems.

The problem can be largely avoided by purchasing high-quality olive oils, which contain many polyphenols. This phytonutrient is considered a natural antioxidant and allows olive oil to remain more stable as it sustainably slows down oxidation. One speaks of a high content of polyphenols when the average value of 250 mg/kg is exceeded. During the taste test, this is reflected in pleasant bitterness and a scratchy on the palate.

What else can you do with rancid olive oil?

Rancid oil can * no longer used for the preparation of food*, but one or the other use is possible in the household. So the oil can still be used for the treatment of wooden boards and other wooden objects, but also for leather shoes. Otherwise, the oil should be disposed of.

How do I properly dispose of old vegetable oil?

Small amounts can be vacuumed up in a sealable container or in cat litter be disposed of in the residual waste. Large quantities, however, should be delivered to the disposal yard. Under no circumstances should oil be disposed of via the sewage system, as this may deposit and clog pipes.