In the world of manufacture, the importance of monitoring for microbiological content of foods, cosmetics, and pharmaceuticals is well known; however, the packaging in which these items are contained is often overlooked
The Unseen Effects of Microbiology in Packaging
In the world of manufacture, the importance of monitoring for microbiological content of foods, cosmetics, and pharmaceuticals is well known; however, the packaging in which these items are contained is often overlooked
Image 1: Aspergillus sp. isolated from secondary packaging of a seasonal box-set
Accrediting bodies such as BRCGS are increasing their requirements regarding environmental monitoring, sixth issue, clause 4.8.5, released 2019. This can be seen as both a blessing for the consumer due to higher quality demands on products, and a curse for manufacturers as demands on quality control grow.
Areas of risk should always be considered for monitoring. An example of high-risk packaging is something that is in direct contact with a final product, such as the card box containing a ready-to-eat wrap. The main concern in this instance is the transfer of pathogens from the packaging to the product inside. A lower risk item would be secondary or tertiary packaging.
Low risk does not mean‘ No Risk’
While a full environmental monitoring program may be unnecessary for low-risk packaging, thought must still be given to such items. Even if the product remains uncontaminated, visual spoilage of secondary packaging can lead to reputational damage and negative brand image— no one wants to be eating or using a product from a box that is visibly spoiled. One common cause of visible spoilage
110 FDPP- www. fdpp. co. uk in card packaging occurs when it is exposed to environmental change after storage at low temperatures or manufacture in humid climates, causing moisture to form. We have seen several cases of this, notably more than once with seasonal boxsets. In these instances, packaging can be made months in advance. It is then grouped and shrink wrapped, creating an ideal
environment for mould to grow. Image 1 shows mould that we isolated from a Christmas box-set.
The products within were unaffected and free from any contamination; however, all sets had to be recalled from stores as the supplier felt that complimentary mould made a poor Christmas gift!
Other factors to consider
Contaminant organisms found on packaging and in the production line may not be typical pathogens, but that doesn’ t mean the product is safe from spoilage, as depicted in image 2 of a cosmetic cream and lid.
After testing a large number of lids, it was found that approximately 10 % had low levels of a Penicillium mould species( sp.).— as little as 1 to 5 colony forming units( cfu) per lid. We established this was connected to the plastic wads in the lids. Given enough time, these low levels of spores were able to grow, forming a colony on the wad, which would then shed spores and grow down the side of the jar and onto the surface of the product.
The product itself had passed the ISO 11930 preservative efficacy testing, also known as challenge testing. The preservative system made sufficient log reductions against the standard five organisms, and it was shown to also be effective against this in-house mould: i. e., although the product was visibly spoiled, the mould in contact with the product was no longer viable. The preservative system was only effective on the mould that was in direct surface contact, leaving colonies on the lid uninhibited. This was confirmed by microscopic examination of the mould on the product’ s surface showing matching conidiophores( the microscopic structures of mould as seen in image 1) to the viable mould growth on the lid, along with traditional plate counts.
by Martin Isom, Director at DLL
Visit us at www. donlab. co. uk for more information on what we do.
One of the easiest ways to monitor packaging is to swab it. Swabs will be reasonably effective at collecting organisms from a non-porous surface, such as plastic.
Image 2: Left, Penicillium sp. growing on the wad of a cosmetic product lid. Right, non-viable mould transferred to the surface of the product from the lid.