Peroxide value (PV) is a common measurement used to assess the oxidation level of oils and fats, which includes krill oil. Oxidation is a chemical reaction that produces peroxides and other reactive species, and it can degrade the quality of oils and fats, altering their taste, smell, and nutritional properties. Oils with a high peroxide value may be rancid or nearing rancidity.
Krill oil is rich in omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are particularly susceptible to oxidation. The PV of krill oil can vary significantly depending on a variety of factors, including the freshness of the krill, the method of oil extraction, how the oil has been stored, and whether any antioxidants (like vitamin E or astaxanthin, a naturally occurring antioxidant in krill) have been added to the oil to help prevent oxidation.
The acceptable limit for peroxide value in edible oils is typically below 10 milliequivalents peroxide per kilogram of oil (meq/kg). However, the lower the PV, the better, as a low PV indicates a low level of oxidation and a fresher, higher-quality oil.
If you're considering using krill oil as a supplement, look for products that provide information about their peroxide value, as this can be a useful indicator of the product's quality and freshness. Remember to store krill oil and other omega-3 supplements as directed, typically in a cool, dark place, to minimize oxidation.