Before you read on, take the six-question quiz and then find out which questions proved the most challenging—and how your knowledge stacks up.
At in-cosmetics Global 2026, we invited visitors to put their knowledge of lipid oxidation to the test by answering six questions as quickly as possible. We continued gathering responses after the event and have now reviewed the results. They reveal several common misconceptions about what really determines the oxidative stability of plant-based oils. Below, we explore the three questions that proved most challenging and explain what the results mean for oil selection and formulation stability.
Misconception 1: crop species or processing alone can predict stability
The first result shows how easy it is to look for a single predictor of oxidative stability. Only 58% of participants recognized both crop and processing matter, while 29% chose processing alone. In reality, the story begins with the oil’s natural composition, particularly its fatty acid profile. Oils with a higher proportion of polyunsaturated fatty acids generally offer more sites where oxidation can begin than oils richer in monounsaturated or saturated fatty acids.
But fatty acid composition is only part of the picture. Oil quality and processing also influence oxidative stability. Carefully controlled purification and processing can reduce oxidation products, impurities and contaminants that may compromise stability, while helping to retain beneficial minor components such as naturally occurring tocopherols. The final stability of an oil therefore reflects the combined effect of its fatty acid profile, minor components and processing history.
For formulators, this means looking beyond the INCI name or crop species. Understanding an oil’s source, composition, and processing methods provides a much clearer picture of how it is likely to perform.
Misconception 2: reducing headspace is the most effective way to slow oxidation
The packaging question revealed a similar tendency to focus on one part of the picture. While 60% of participants correctly identified high-barrier packaging that limits oxygen and light exposure as the most effective option, 31% selected less headspace. Reducing headspace does lower the amount of oxygen initially trapped inside the packaging. However, it does not necessarily prevent more oxygen from entering over time.
What happens throughout the product’s life depends on the overall packaging system, not only the space above the product, but also the barrier properties of the container, closure and seals. Light adds another layer to the challenge because it can accelerate oxidation, particularly in oils or formulations containing photosensitive components. Well-designed high-barrier packaging therefore offers broader protection by limiting both oxygen transmission and light exposure.
Headspace still has a role to play, but it is best viewed as one part of a wider stability strategy. For formulators, the key is to consider how the packaging as a whole helps limit exposure to oxygen and light throughout storage and use. Alongside packaging, storage duration and temperature influence how oxidation develops.
Misconception 3: antioxidants can compensate for an unstable base oil
The final result points to a common hope in formulation: that antioxidants can make up for an unstable base oil. Although 71% correctly identified that inherently stable oils generally contain fewer oxidation-sensitive sites, 25% believed that antioxidants could replace the need for testing, and 4% thought they could stop oxidation altogether.
The reality is more nuanced. An oil’s susceptibility to oxidation is rooted in its fatty acid composition. Double bonds are especially vulnerable, which means oils rich in polyunsaturated fatty acids generally contain more reactive sites than those richer in monounsaturated or saturated fatty acids. Antioxidants can interrupt reactions in the oxidation chain and delay oxidation, but they cannot prevent it completely. How well they work also depends on the antioxidant system and concentration, the composition of the oil, processing conditions, packaging and storage.
Rather than relying on antioxidants alone to compensate for an oxidation-sensitive oil, formulators can build stability from the base upwards by first choosing an oil with the level of inherent stability required for the application and then using antioxidants as an additional layer of protection. Stability testing remains essential for understanding how the combined system performs over time.
From a simple quiz to better stability decisions
The quiz results underline a simple point: lipid oxidation cannot be understood—or managed—through a single indicator. Fatty acid composition, oil quality and processing, naturally occurring antioxidants, exposure to oxygen, light and heat, trace metals and other pro-oxidant impurities, packaging, and oxidation development over time all influence the final outcome. Looking at these factors together supports more informed ingredient selection, more meaningful stability testing and, ultimately, more robust formulations.
Want to deepen your understanding of lipid oxidation? Watch our online masterclass to explore the science behind oxidative stability and learn how oil composition, processing, testing and packaging can inform more robust formulation decisions.
