With frozen food a bag and a container do not do the same job. The Codex code of practice for quick frozen foods asks the packaging to protect the product against drying out and contamination, and asks for transport in suitable insulated equipment with product that starts at -18 °C or colder.
| Layer | Job |
|---|---|
| Product packaging | Protects the product against drying and contamination |
| Inner bag or liner | Limits leakage and contact |
| Insulated container and cold source | Holds the temperature |
For frozen goods GEBHARDT recommends pre-cooling the container to between -21 and -25 °C; the Isotec TBX keeps the cold chain for up to 24 hours with eutectic plates.
With partial unloading the work starts at the mouth of the bag. As the load shrinks the mouth no longer closes the same way, and frost or a fold of liner can get into the closure. Rehearse opening, removing product and re-closing in the real order of the orders, and if a proper closure cannot be achieved, pack the orders separately before dispatch. Measure the temperature with a probe placed between product packs.
