- Unsaturated Fats, including polyunsaturated
and monounsaturated fats
are susceptible to rancidity
- There may be possible negative health effects from ingestion
of oxidized lipids from fish oils and cooking oils (Halvorsen
- Auto-oxidation and photo-oxidation during processing and
storage (Halvorsen 2011)
- Undesirable taste, decomposing nutritional quality, production
of toxic compounds
- Depends on fatty acid composition (degree of unsaturation),
processing, exposed heat, light, metals, and antioxidants.
- Plastic containers
- Placicides can contaminate food with Bisphenol A (BPA)
- BPA from plastics links to lipid molecules
- BPA is found in:
- certain plastic containers
- plastic coating in some metal cans
- and other plastics
- See Hormone Disrupters:
Bisphenal A (BPA)
- Shelf life for cooking oils vary from 2 to 12 months
- 3-6 weeks
- Flax and hemp oils
- May be kept up to a year in the freezer
- 2-4 Months
- 3 Months
- 3-6 Months
- 6 Months
- Safflower, Soybean, and Peanut oils
- 6-12 months
- Olive, Macadamia, and Almond Oils
- 9-12 months
- 12 months
- Coconut, Palm, Avocado, and Canola Oil
- Refined oils will keep refrigerated for 6 months to a year.
- Unrefined oils are less stable and will only keep for 4 or
- purchase them in small quantities
Grootveld M, Silwood CJL, Addis P, Claxson A, Serra BB,
Viana M (2001). "Health effects of oxidized heated oils".
Foodservice Research International 13: 4155.
Guillén M, Uriarte P (2012). Aldehydes contained
in edible oils of a very different nature after prolonged heating
at frying temperature: Presence of toxic oxygenated a,ß
unsaturated aldehydes. Food Chemistry 131 (3), 915926.
Halvorsen BL, Blomhoff R (2011). Determination of lipid
oxidation products in vegetable oils and marine omega-3 supplements.
Food Nutr Res. 2011;55. doi: 10.3402/fnr.v55i0.5792.
Przybylski O, Aladedunye FA (2012). Formation of trans
fats during food preparation. Can J Diet Pract Res. 2012 Summer.