By Aditi Rungta*
In India, up to 40 percent food is wasted annually according to a study conducted by the United Nations Development Programme. It is alarming to hear about such figures. There is a lot of measures that can be taken to curb such huge amount of losses. Food packaging can play a very important role in reducing losses by enhancing the shelf life of foods by providing a barrier for moisture, oxygen and microorganisms. Be it packaging at the primary level or tertiary processing, packaging can reduce food losses to a great extent. But packaging does come with its flaws if not performed properly. There are chances of pack leakage which can be more detrimental than beneficial. This can lead to food loss, food spoilage and also if undetected can lead to food toxicity if consumed by the customer and can turn out to be fatal. Thus, pack leakage detection is imperative to prevent such losses.
Package integrity can be hampered by one of the following reasons; the film pores might be large by stretching of the material, improper sealing or product caught in the seal of the package. Manual squeeze tests are performed to inspect leak detection. This method is not sufficient as small but significant leaks might not be detected. There are various leak detection methods that can be employed. This way the pack can be recalled if there are any flaws in the package. Few of the leak detection techniques used are:
1. Bubble test
The pack is immersed in a water bath and any leakage will be detected by release of bubbles from the pack visible in the water bath. But, using this method, minor leakage can’t be detected.
2. Vacuum chamber test
Packs placed inside a vacuum chamber are exposed to increasing vacuum and any leakages are detected if the pack loses its airtight condition.
3. Dye penetration test
Empty packs are injected with methylene blue dye and any ink penetration in the seal area by capillary action due to sealing faults is detected.
These and many other methods can be employed in leakage detection depending on the kind of pack, the type of packaging material, limit of leakage rate acceptability etc. Also, caution needs to be taken while filling the pack to avoid contamination of the seal area, sealing temperature should be maintained to ensure proper sealing. Food manufacturers should employ these methods so as to minimize wastage and losses.