Oxygen barrier performance of plastic yoghurt cup by ox2 / 230 constant pressure oxygen permeameter

Abstract: yogurt is convenient to carry and easy to be digested and absorbed by human body, which is a common nutritional food in public life But because it contains a lot of fat and protein, it is easy to be oxidized by oxygen in the air Therefore, in order to ensure that yoghurt products are not prone to quality problems within their shelf life, and to obtain a longer shelf life, the yoghurt cup used must have a higher oxygen resistance, generally the lower the oxygen permeability, the better the oxygen resistance This paper mainly introduces the testing method and principle of oxygen resistance of yoghurt cup, details the testing process and other technical information, and provides a solid reference for related industries Key words: yoghurt, dairy product, yoghurt cup, oxygen resistance, barrier, oxygen permeability, oxidation deterioration, vessel oxygen permeability test, oxygen permeability test system test significance: yoghurt is a kind of high nutrition dairy product which is added with special beneficial bacteria (i.e fermentation agent) to pasteurized fresh milk and cooled and filled after fermentation Yogurt contains a lot of protein, fat, vitamins and beneficial bacteria and other nutrients, and it is easy to be digested and absorbed by the human body In view of the processing needs and convenience for consumers, most of the yoghurt products are packed in cups, while most of the yoghurt cups used are plastic ones, mainly made of PP, PS and PE, i.e common white plastic cups, but also paper-based yoghurt cups made of PE / paper / PE composite materials At the same time of filling yoghourt, yoghourt cup also needs to be sterilized in different ways to ensure that yoghourt is not easily caused by other harmful bacteria Meanwhile, in order to prevent the quality problems of yoghurt from oxidation and deterioration, the requirements for oxygen resistance of yoghurt cup are also high If its oxygen resistance is poor, yoghurt is easy to be oxidized by the oxygen infiltrated into the yoghurt from the outside, resulting in such quality problems as yoghurt mildewing, cup swelling and yoghurt being tofu dregs The thicker the plastic yoghurt cup is, or the higher the density of the material used, the higher the barrier of the yoghurt cup, including oxygen resistance and moisture resistance How to monitor the oxygen barrier of the yoghurt cup and whether the oxygen barrier of the yoghurt cup meets the quality requirements of the marked shelf life depends on the indicator of oxygen permeability The smaller the transmittance is, the higher the oxygen barrier is Based on the oxygen transmittance testing instrument for testing containers, this paper introduces the testing process and method principle of the oxygen transmittance of yoghurt cup made of PP in detail, which provides a powerful technical reference for the production and use of yoghurt cup Figure 1 example of yoghurt cup test method: In the world, there are two kinds of methods to measure the oxygen transmittance: the isobaric method and the differential pressure method The isobaric method uses the Coulomb sensor to absorb the oxygen passing through the film, and converts it into the current signal, so as to calculate the oxygen transmittance Its detection limit is low, and it can measure the oxygen transmittance of the high barrier material, and the isobaric method can break through the inevitable pressure difference between the two sides of the plastic container Thus, the oxygen permeability of the test vessel can be expanded Therefore, the constant pressure method (i.e Coulomb electricity sensor method) is mostly used to test the oxygen permeability of container packaging materials at home and abroad However, in recent years, relevant instrument manufacturers have gradually solved the impact of the pressure difference method on the container and developed a low barrier packaging container (i.e high gas permeability) that can be tested The oxygen permeability test of vessels by isobaric method at home and abroad mainly follows the international standard ASTM F 1307 measurement of oxygen transmission rate of dry solid packaging by power consumption sensor, and there is no relevant domestic standard at present We will use the ox2 / 230 oxygen transmittance test system independently developed by Labthink Languang company to test the oxygen transmittance of PP yoghurt cup samples in combination with the above standards 1 The test instrument ox2 / 230 oxygen transmittance test system (Labthink Languang), with three independent chambers and ultra-high precision, can test three identical or different samples at the same time On the basis of ensuring the independent test of samples, the test efficiency is increased by three times Temperature control range is 15 ℃ ~ 55 ℃, humidity control range is 0% RH, 35% RH ~ 90% RH The system can test the oxygen permeability of the container in the range of 0.0001 ~ 60cm 3 / (PKG · d) At the same time, the system can also test the oxygen permeability of the film in the range of (0.01 ~ 6, 500) cm3 / M 2 · 24h and can be extended to (0.07 ~ 65000) cm3 / m2 · 24h The system Zui can support parallel connection of 10 instruments and establish a system for simultaneous test of 30 samples The instrument meets the requirements of ASTM f1307, ISO 15105-2, GB / T 19789, ASTM d3985, ASTM F 2622, ASTM f1927, JIS k7126-2, YBB 00082003 A variety of national and international standards can meet the oxygen permeability test of bottles, bags, cans, boxes, barrels and other containers made of plastic, rubber, paper plastic composite, glass, metal and other materials under different temperature and humidity environment, such as yogurt cup, cola bottle, peanut oil barrel, Tetra Pak packaging, vacuum packaging bag, metal three piece can, plastic cosmetics packaging, toothpaste hose, jelly cup, etc It can also test the oxygen barrier of various plastic films, sheets and other materials Fig 2 preparation of 2 sample for OX2/230 oxygen transmission test system, 3 good yogurt cup samples were placed in the laboratory for 23 hours and 50%RH for 48 hours 3 Place of test conditions: Jinan Languang packaging safety inspection center test temperature and humidity: 23 ℃, 50% RH test method: isobaric method (i.e Coulomb sensor method) 4 Test step 4.1 test principle ox2 / 230 By using the principle of isobaric method, the sample is clamped between the test chambers, oxygen or air flows on one side of the film, and high-purity nitrogen flows on the other side of the film Oxygen molecules diffuse through the film to high-purity nitrogen in the other side and are carried to the sensor by the flowing nitrogen Through the analysis of the oxygen concentration measured by the sensor, parameters such as oxygen transmittance can be calculated For packaging containers, high-purity nitrogen flows in the container, and air or high-purity oxygen surrounds the outside of the container 4.2 the sample clamping shall be sealed on the vessel sealing device with transparent quick fix adhesive; after sealing, it shall be clamped inside the vessel testing device, and then the parts above the tray of the vessel sealing device shall be tightly wrapped with sealing bag Clamp the other 2 samples according to the above method 4.3 automatic test of detection process, simple test process: add distilled water, open system air source, and adjust air source pressure as required According to the test requirements, add a proper amount of distilled water to achieve the required O2 and N2 humidity Turn on the power and run the software Set the test temperature, test parameters and start-up test Test parameters include control parameters (test mode, test cycle times, test time, rezero cycle times, etc.) and sample parameters (type, area, thickness, etc.) Humidity and carrier gas flow shall be adjusted during the test End of test, data processing Turn off the air supply and power supply The average oxygen transmittance of the three yoghurt cups was 0.0571 cm 3 / (PKG · d) Conclusion: when using Labthink blue ox2 / 230 oxygen transmittance test system to test the oxygen transmittance of plastic yoghurt cup, we can get high-precision results of oxygen resistance and accurately reflect the barrier performance of yoghurt cup The testing equipment and standards used in this test are also applicable to the oxygen permeability test of vessels with certain barrier for other purposes Labthink Languang has been committed to providing professional testing services and equipment for customers around the world Over the years, it has provided thousands of barrier testing services for customers around the world and provided reliable data support for customers For more information about related testing instruments, you can visit www.labthink. For more information or call Labthink is looking forward to enhancing technical exchanges and cooperation with enterprises and institutions in the industry Copyright notice: All rights reserved Jinan Languang Electromechanical Technology Co., Ltd no reprint without permission!