A single-serve coffee container, also known as coffee capsule, is a method for coffee brewing that prepares only enough coffee for a single portion.

Single-serve coffee containers can both reduce the time needed to brew coffee and simplify the brewing process by eliminating the need to measure out portions, flavorings, and additives from large bulk containers. They can also help to keep the unused product fresher by individually packaging portions separately without exposing the entire supply batch to air and light.

The coffee capsule is composed of body made of food degree PP and aluminum foil cover. Such package has good barrier property to oxygen, moisture and light. That’s why the shelf life of coffee capsule is up to 2 years. In addition, the fragrance of the coffee can be retained as long as possible by using such package.

It can be easily understood that if the body of capsule does not have sufficient barrier property, the coffee packed inside cannot be protected from oxygen or moisture properly and as a result, the flavor of the coffee may be compromised or even worse the coffee may get deteriorated. Therefore, it is necessary to measure the barrier property of the body of coffee capsule before use.

This article provides a simplified test method of the oxygen barrier property of the body of coffee capsule, which is usually made of PP. The testing instrument used for oxygen permeability tests is Labthink’s OX2/230 Oxygen Transmission Rate Test System. This instrument uses a coulometric detector to determine the oxygen transmission rate. The specimen is mounted as a sealed semi-barrier between two chambers at ambient atmospheric pressure. One chamber is slowly purged by a stream of nitrogen at a given temperature and relative humidity and the other chamber is purged by a stream of oxygen at the same temperature as the nitrogen stream but may have a different relative humidity than the nitrogen stream. In this case the environment would more closely simulate actual shelf conditions. As oxygen gas permeates through the film 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 time. Note: For the package specimens, nitrogen flows inside the package while oxygen flow outside the package.

Figure 1. Coffee Capsules

The tests shall be performed according to the following procedures.

(1)    Paste the body of coffee capsule on the test plate with Aradite Rapid Transparent Adhesive. Place the specimen with test plate into the package hood. Cover the specimen with a bag.

(2)    Set test temperature, test humidity and other test parameters in the software interface. Then click Test to start the test.

(3)    Adjust humidity and carrier gas flow rate as required.

(4)    The system will calculate and display the test results after tests.

For more details about OX2/230 Oxygen Transmission Rate Test System, 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.