Effects of frying oils' fatty acids profile on the formation of polar lipids components and their retention in French fries over deep-frying process

- Oligomeric and dimeric triacylglycerols were preferred to be retained in French fries while oxidized triacylglycerols and diacylglycerols content was higher in deep-fried oils.
- The polar compounds content was positively correlated with the formation of trans-C18:1.
- Linoleic acid, instead of oleic acid, plays a crucial role in the formation of polar compounds in palm oil rather than in palm kernel oil and coconut oil.

The effects of frying oils' fatty acids profile on the formation of polar components and their retention in French fries and corresponding deep-fried oils were investigated in the present study, using oils with different fatty acids composition. Our analysis showed that the total polar compounds (TPCs) content in French fries was only slightly lower than that in deep-fried oils, indicating that there was no significant difference considering the amounts of TPCs in French fries and deep-fried oils. Our further analysis showed that different polar components in TPCs distributed differently in deep-fried oils and oils extracted from French fries. Specifically, the level of oligomeric and dimeric triacylglycerols was higher in French fries while oxidized triacylglycerols and diacylglycerols content was higher in deep-fried oils. The different retention of TPCs components in French fries may be explained by their interactions with carbohydrates, which are shown to enhance with the increase of hydrophobic property. Chemometric analysis showed that no correlation between the polar compounds level and saturated fatty acids profile was observed. Meanwhile, the polar compounds content was highly correlated with the formation of trans-C18:1, and a highly positive association between polar compounds and C18:2 content was also observed in palm oil.