How cooking oil processing kills its healthy stuff
Influence of refining processes on the bioactive composition, in vitro antioxidant capacity, and their correlation of perilla seed oil
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When they clean perilla seeds to make oil, some good nutrients get lost. The study checked how each cleaning step removes these nutrients and how that affects the oil’s ability to fight free radicals in a test tube.
Surprising Findings
Phenolic compounds and phytosterols showed no significant correlation with any antioxidant measure, despite being widely assumed to be antioxidants.
Most nutrition content claims focus on phenolics and phytosterols as key antioxidants—this study says they played no measurable role in antioxidant activity in this test system.
Practical Takeaways
If you buy perilla oil for its antioxidants, choose cold-pressed, unrefined versions to preserve tocopherols and lutein.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When they clean perilla seeds to make oil, some good nutrients get lost. The study checked how each cleaning step removes these nutrients and how that affects the oil’s ability to fight free radicals in a test tube.
Surprising Findings
Phenolic compounds and phytosterols showed no significant correlation with any antioxidant measure, despite being widely assumed to be antioxidants.
Most nutrition content claims focus on phenolics and phytosterols as key antioxidants—this study says they played no measurable role in antioxidant activity in this test system.
Practical Takeaways
If you buy perilla oil for its antioxidants, choose cold-pressed, unrefined versions to preserve tocopherols and lutein.
Publication
Journal
Journal of Food Science
Year
2020
Authors
Fengguang Pan, Baoli Wen, Xiangdan Luo, Chunshuang Wang, Xiaoqing Wang, Xinrui Guan, Yufei Xu, Wenjun Dang, Mingdi Zhang
Related Content
Claims (6)
Even though phenols and phytosterols are often thought to be healthy antioxidants, in this lab test of perilla oil, they didn’t seem to help at all in fighting free radicals.
When perilla seed oil is processed for commercial use, it loses most of its natural antioxidants—especially lutein, which disappears entirely during one step—and other important compounds like phenols and tocopherols are also reduced.
In lab tests, the vitamin E-like compounds (tocopherols) in perilla oil are strongly linked to its ability to fight free radicals in two different ways, while the yellow pigments (carotenoids) are only linked to one of those tests.
When perilla oil is treated with alkali (neutralization), it loses the most phytosterols—more than any other step—meaning this part of processing really strips away a valuable nutrient.
This is the first time anyone has tracked how the yellow pigments in perilla oil change during processing—and they found that the main one, lutein, vanishes completely when the oil is bleached.