Abstract: Yogurt is easy to carry and easy to be digested and absorbed by the human body. It is a common nutritious food in the public life. However, because it contains a lot of fat and protein, it is easily oxidized by oxygen in the air to cause deterioration. Therefore, in order to ensure that the yogurt product is not prone to quality problems during its shelf life, and to obtain a longer shelf life, the yogurt cup used must have a higher oxygen barrier property. Generally, the lower the oxygen transmission rate, the better the oxygen barrier property. . This paper mainly introduces the test method and principle of oxygen barrier of yogurt cup, details the technical information of its test process, and provides a solid reference for related industries.
Key words: yogurt, dairy products, yogurt cup, oxygen barrier, barrier properties, oxygen transmission rate, oxidative deterioration, container oxygen transmission rate test, oxygen transmission rate test system
Test significance:
Yogurt is a high-nutrient dairy product that is added to a pasteurized fresh milk by adding a special variety of beneficial bacteria (ie, a starter) to the body after fermentation. Yogurt contains a lot of nutrients such as protein, fat, vitamins and beneficial bacteria, and is easily digested and absorbed by the body. In view of the processing needs and consumer convenience, most yogurt products are cups, and most of the yogurt cups used are plastics. The materials are mainly PP , PS and PE , which are common white plastic cups, but also include Paper-based yogurt cup with PE/ paper /PE composite material. While filling the yogurt, the yogurt cup also needs to be sterilized in different ways to ensure that the yogurt is not easily deteriorated by other harmful bacteria. In order to prevent the oxidative deterioration of yogurt, the oxygen barrier requirement of the yogurt cup is also high. If the oxygen barrier property is poor, the yogurt is easily oxidized by the oxygen permeating from the outside, and the yogurt is mildewed and rises. Cups and yoghurts are quality problems such as bean curd.
The thicker the plastic yogurt cup, or the higher the density of the material used, the higher the barrier properties of the yogurt cup, including oxygen barrier and moisture barrier. How to monitor the barrier of the yoghurt cup to the outside oxygen, whether the oxygen barrier of the yoghurt cup meets the quality requirements of the indicated shelf life, it is necessary to rely on the detection of its oxygen transmission rate. The smaller the transmittance, the oxygen barrier. The higher the sex. Based on the oxygen transmission rate measuring instrument for testing containers, this paper introduces the testing process and method principle of the oxygen permeability of the yogurt cup made of PP , which provides powerful information for the production and use of yogurt cups. Technical reference.
Figure 1 yogurt cup example diagram
Detection method:
The international oxygen transmission rate test method is divided into equal pressure method and differential pressure method. The equal pressure method uses a coulomb electricity sensor to absorb oxygen passing through the membrane and convert it into a current signal, thereby calculating the oxygen transmission rate, and the detection limit thereof. Low, can accurately test the oxygen transmission rate of high barrier materials, and the equal pressure method can break through the pressure difference method due to the inevitable influence of the pressure difference on both sides of the plastic container, thereby expanding the oxygen transmission rate of the test container. Therefore, the oxygen transmission rate of test container packaging materials at home and abroad is mostly tested by the isobaric method (ie, Coulomb electricity sensor method), but in recent years, related instrument manufacturers have gradually solved the impact of differential pressure method on containers. A gas barrier property has been developed to test low barrier packaging containers (i.e., high gas permeability).
The oxygen transmission rate test of the isobaric test container at home and abroad mainly follows the international standard of ASTM F 1307 "Measurement of oxygen transmission rate of dry solid packaging materials by using electricity consumption sensor", and there is no relevant domestic standard. We will use the OX2/230 oxygen transmission rate test system independently developed by Labthink to combine the above standards to test the oxygen permeability of PP cup yoghurt cup samples.
1 , test equipment
OX2 / 230 oxygen transmission rate test system (Labthink blue light), three independent chambers, ultra-high precision, which can be the same or different three test specimens, on the basis of the tests to ensure independent samples, the test efficiency by 3 Times. The temperature control range is from 15 °C to 55 °C , and the humidity control range is 0% RH and 35% RH ~ 90% RH . The system can test the oxygen transmission rate of the container in the range of 0.0001 ~ 60 cm 3 / (pkg · d) , and the system can also test the oxygen transmission rate of the film, the test range is (0.01 ~ 6 , 500) cm 3 / m 2 · 24h and can be extended to (0.07 ~ 6,5000) cm 3 /m 2 ·24h . Zui system 10 can support multiple instruments are connected in parallel, the establishment of an efficient system 30 test specimens simultaneously.
The instrument meet ASTM F1307, ISO 15105-2, GB / T 19789, ASTM D3985, ASTM F 2622, ASTM F1927, JIS K7126-2, YBB 00082003 a number of national and international standards, to meet the temperature and humidity environment different plastics, rubber Oxygen transmission rate test of bottles, bags, cans, boxes, barrels, etc. made of paper, paper-plastic composite, glass, metal, etc., such as yogurt cup, cola bottle, peanut oil drum, Tetra Pak packaging, vacuum packaging bag , metal three-piece cans, plastic cosmetic packaging, toothpaste hoses, jelly cups, etc. It can also test the oxygen barrier properties of various plastic film and sheet materials.
Figure 2 OX2/230 oxygen transmission rate test system
2. Preparation of samples
The three intact samples placed in a laboratory yogurt cups 23 ℃, 50% RH environment adjustment state for 48 hours.
3. Test conditions
Location: Jinan Languang Packaging Safety Testing Center Test Temperature and Humidity: 23 ° C, 50% RH
Test method: Isobaric method (ie Coulomb sensor method)
4. Test procedure
4.1 Test principle
The OX2/230 uses the isostatic test principle to clamp a pre-treated sample between test chambers, with oxygen or air flowing on one side of the membrane and high purity nitrogen flowing on the other side of the membrane. Oxygen molecules diffuse through the membrane to the high purity nitrogen in the other side and are carried to the sensor by the flowing nitrogen. By analyzing the oxygen concentration measured by the sensor, parameters such as oxygen transmission rate are calculated. For packaging containers, high purity nitrogen flows within the container, and air or high purity oxygen surrounds the outside of the container.
4.2 sample clamping
The sample is sealed on the container sealing device with a transparent quick-setting glue; after the sealing is completed, it is clamped inside the container testing device, and then the sealing bag is used to tightly wrap the above portion of the container sealing device tray. The other two samples were clamped as described above .
4.3 Detection process
- Automated testing, the testing process is simple:
- Add distilled water, turn on the system air supply, and adjust the air supply pressure as required. According to the test requirements, an appropriate amount of distilled water is added to achieve the required O 2 , N 2 humidity.
- Turn on the power and run the software.
- Set test temperature, test parameters, and start test. Test parameters include control parameters (test mode, number of test cycles, test time, number of REZERO cycles, etc.) and sample parameters (type, area, thickness, etc.).
- The humidity and carrier gas flow rate are adjusted during the test.
- End of test, data processing.
- Turn off the air supply and power supply.
The average oxygen transmission rate of the three yogurt cup samples in this test was 0.0571 cm 3 /(pkg·d) .
to sum up:
When using yogurt cups oxygen transmission rate of Labthink OX2 / 230 oxygen transmission rate test system for testing of plastics material, the oxygen barrier properties can be obtained with high accuracy results, accurately reflect the barrier properties of the yogurt cups. The testing equipment and testing standards used in this test are also applicable to the oxygen transmission rate test of containers with certain barrier properties for other purposes. Labthink has been committed to providing professional testing services and equipment to customers around the world. Over the years, it has provided tens of thousands of barrier testing services to customers around the world, providing customers with reliable data support. Learn more testing instruments concerning the information, you can visit . Com to view specific information or call advisory. Labthink is looking forward to enhancing technical exchanges and cooperation with enterprises and institutions in the industry.
Copyright statement: Article Copyright Jinan Languang Electromechanical Technology Co., Ltd., reprinted without permission!
Preservation tubes are swabs with disposable virus sampling tubes to collect DNA tests for disposable nasal flocking sterile medical transport.
swabs with disposable virus sampling tubes , to collect DNA tests for disposable nasal flocking sterile medical transport.
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