Hi All,
I am working on a sustainability project involving the transition from a non-recyclable packaging material (High Impact Polystyrene) to a more recyclable material, most likely PET however other materials are being considered.
One of the challenges I am facing is the temperature limits that PET and other recyclable materials have. The product is a low acid dairy dessert product, the pH of the final product is between 6.4-6.7 with a high water activity. The proposed solution that I have been tasked with is to transition the filling process from a hot filling process to a cold fill process in order to use this new material, there are issues surrounding the viscosity of the product that come with this but that is not why I am writing today. The main issue I want your guys thoughts on is the food safety risks that come with this.
The product is heat treated at 95oC for 5 minutes and is filled into its packaging at a minimum of 65oC. The product is non-shelf stable and is kept refrigerated during storage and throughout the supply chain. The proposed fill temperature to enable the new packaging is cold, so around 4oC. I have been informed by an outside advisor that psychrotrophic B.cereus spores may potentially be present on the packaging and without that final hot filling process this may be an issue. I have also been informed that yeasts and moulds could potentially be present on the packaging and this could potentially be another failure point. If there are other pathogenic or spoilage microbiological concerns you think I need to be aware of please let me know.
Antimicrobial additives are in scope for this project and based on the limited literature I have read Potassium sorbate and Nisin are potential contenders for inhibiting B.cereus, Nisin however is particularly expensive and does not handle the heat treatment process particularly well. I wanted your thoughts on any other mitigations that could be used for this project.
Another route that could potentially be investigated is going about the process through the packaging, there are potential additives that could be used to increase the temperature that PET can endure during the hot filling process. This then introduces concerns about the chemical leaching that could occur at elevated temperatures.
If there are any processing changes you think may work I would love to hear them.
Thanks for your time if you've made it this far,
If you've got any further questions please sing out,
Kind regards