Dairy drinks are very common consumer products in people’s daily life. Peanut milk, walnut milk and many other beverage containing milk are very popular. Dairy milk is mainly made of fresh milk, which contains a large amount of protein, vitamin and fat. Those nutrients are liable to be oxidized, which should be kept away from light. The packaging materials used for dairy drinks should have sufficient oxygen barrier property. Otherwise, those nutrients may be oxidized and the dairy drinks may get deteriorated.

The packaging for dairy drinks include tetra pak, bottles or cans made of plastics or metals. Different packaging materials may have distinct oxygen barrier property. In this article, we take plastic bottle as an example to explain how to test the oxygen barrier property of the packaging for dairy drinks. The testing instrument is Labthink’s OX2/231 Oxygen Transmission Rate Tester.

In the tests, the pre-conditioned specimen is mounted between the upper and lower chambers at ambient atmospheric pressure. One chamber contains oxygen and the other chamber is slowly purged by a stream of nitrogen. Due to the concentration difference between the two chambers, oxygen molecules permeate through the specimen into the nitrogen side and are taken to the coulometric sensor where proportional electrical signals are generated. The oxygen transmission rate is then obtained by analyzing and calculating the signals. For package samples, high purity nitrogen flows inside the package, and oxygen flows outside.

Figure 1 Common Packaging for Dairy Drinks

Figure 2. OX2/231 Oxygen Transmission Rate Tester

The tests shall be performed according to the following procedures.

(1)   Condition the specimen in a desiccant container at 23℃ for 72 hours.

(2)   Remove the specimen from the desiccant container and fix it on a sample support with rapid transparent adhesive. Make sure the specimen is sealed tightly.

Figure 3. Seal the Specimen

(3)   Place the specimen with sample support into the testing instrument and cover the specimen with an aluminum foil bag.

(4)   Set test temperature, test humidity and other test parameters. Click Start Test to start the tests.

(5)   The test results will be calculated and displayed automatically after tests.

For more details about OX2/231 Oxygen Transmission Rate 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.