Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body and have other health benefits.

EPA and DHA contained in the fish oil are unsaturated fatty acids. That’s why the fish oil should be kept in a well-closed, light-resistant, cool and dry place to protect those nutrients from oxidization.

How to guarantee the quality of the fish oil within its shelf life? The most effective way is to select suitable packaging materials for the fish oil and store it in proper environment. The packages used for the fish oil should be non-transparent and light-proof. In addition, the oxygen barrier property of the packaging materials used for fish oil should be controlled properly. Otherwise the fish oil may be oxidized by the oxygen permeating through the packaging. Currently the main packages widely used for fish oil include glass bottle and plastic bottle.

This article provides simplified procedures for oxygen permeability test of the plastic bottles for fish oil capsules for your reference. The testing instrument is Labthink’s OX2/231 Oxygen Permeability Tester, which uses coulometric oxygen sensor when measuring the OTR of test specimens.

According to ASTM F1307, The package is mounted in such a way as to provide that the inside of the package is slowly purged by a stream of nitrogen while the outside of the package is exposed to a known concentration of oxygen.  As oxygen permeates through the package walls into the nitrogen carrier gas, it is transported to the coulometric detector where it produces an electrical current, the magnitude of which is proportional to the amount of oxygen flowing into the detector per unit of time.

Figure 1. Common Fish Oil Capsule Bottles

The specimens can be tested in the following procedures.

l  Condition the prepared specimens in the environment specified in the standard.

l  Fix the specimen on the sample support with Araldite adhesive. Mount the sample support with specimen in the instrument. Seal the specimen and its mouth with an aluminum foil cover.

l  Set test temperature, test humidity and other test parameters. Start test.

l  The test results will be given by the instrument automatically.

For more details about Labthink’s OX2/231 Oxygen Permeability Tester, please visit www.labthink.com

About Labthink Instruments Co., Ltd:

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.