Vegetable oil oxidation and how it affects quality and shelf life
What it found
Vegetable oils react with light, heat and oxygen to form compounds that lower nutritional value, cause off-flavours and may pose health risks.
The paper reviews how this happens, how it is measured, and ways to slow it down.
What they found
How oxidation happens
Oils oxidise through three main routes: photo-oxidation, enzymatic oxidation and auto-oxidation. Photo-oxidation is described as the most harmful to oxidative stability, and it runs much faster than auto-oxidation.
What oxidation produces
Oxidation first forms peroxides and hydroperoxides, which quickly break down into aldehydes, ketones, alcohols and other volatile compounds. These are responsible for the rancid, stale or paint-like smells that put shoppers off.
Nutritional losses
Oxidation reduces the content of unsaturated fatty acids, fat-soluble vitamins such as A, D, E and K, and natural antioxidants like tocopherols. It also produces compounds such as malondialdehyde and 4-hydroxynonenal.
Health concerns
The paper says oxidation products can cause biological reactions in the body and that some, such as 4-hydroxyhexenal, are stable and absorbed from the intestine into the bloodstream. It lists cancer, atherosclerosis, heart disease, allergic reactions and inflammation among the health risks linked to these compounds over time.
Measuring oxidation
Peroxide value and K232 measure early oxidation, while p-anisidine value, K270 and TOTOX measure later stages. The paper notes that a low peroxide value generally means better oil quality.
Slowing oxidation down
The oil industry often adds synthetic antioxidants to slow oxidation, and enriching oils with natural antioxidants is another approach. The paper also describes accelerated tests such as Rancimat and the Schaal oven test for predicting shelf life.
What the authors conclude
“Therefore, understanding and controlling oxidation in vegetable oils is critical to preserving their nutritional benefits and ensuring consumer safety.”
Also in their conclusions
- They say that choosing the right methods, suited to each food type, is crucial for accurately measuring lipid oxidation and antioxidant capacity.
- They advise that understanding and controlling oxidation in vegetable oils is critical to preserving their nutritional benefits and ensuring consumer safety.
- They state that regular monitoring and antioxidant strategies are essential to preserve the sensory integrity of vegetable oils.
How it was done
Vegetable oils are a main source of dietary fats and essential fatty acids, but they are highly sensitive to light and heat, which speeds up oxidation. The authors say this is a major concern for the food industry because it reduces nutritional value, causes off-flavours and can produce potentially toxic compounds.
The authors reviewed published research on vegetable oil oxidation, including its mechanisms, its effects on oil quality, methods for measuring it, shelf-life prediction and ways to prevent it. They also analysed 1810 publications from the Scopus database covering 2000 to 2024.
What it can’t tell you
- This is a review of published research, not a new experiment, so it cannot show cause and effect in people.
- The health concerns described come from other studies and reports, not from a single controlled trial in people.
- The paper does not give a level of oxidation products in everyday diets that would or would not affect health.
Who paid
- Conflicts
- The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Authors work at
- Ibn Zohr University, Morocco; INTI International University, Malaysia; Mohammed V University in Rabat, Morocco
The paper
- Title
- Vegetable oil oxidation: Mechanisms, impacts on quality, and approaches to enhance shelf life
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Summarised from
- Full text
- Cite
- Gharby S, Asbbane A, Nid Ahmed M, et al (2025). Vegetable oil oxidation: Mechanisms, impacts on quality, and approaches to enhance shelf life. Food chemistry. doi:10.1016/j.fochx.2025.102541Free full textPubMed 40491699DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error