Processed meat
Packaging: protection from the elements
In processed meat products such as charcuterie and ham, we’ve observed a loss of colour over time if they are not protected from external conditions during storage.
Oxygen can affect pigmentation when the product is exposed to the light, turning it an unappetizing greyish-brown colour. In processed meat products, the desired oxygen level us often lower than 1%, and even as low as 0.2% for sliced ham (pork products are extremely delicate).
What are the leakage rate acceptance criteria for meat packaging?
Leakage measurements focus on the speed at which the oxygen level is increasing, according to the leakage rate or the equivalent defect dimensions in µm. Acceptance criteria grow more stringent as the conservation time increases. In France, legislation states that a use-by date must be no longer than 3 months.
Moreover, manufacturers must also consider the mode of transport and the effects of pressure variations on the packaging. The admissible leakage acceptance criteria must also take into consideration the breathability of the packaging and the head space exchange rate according to stress conditions. In short, a packet with a small head space will expose the product more, replacing the internal volume more quickly.
Unlike fresh meat, which is often packed in transparent packaging, a high oxygen level will colour the meat but considerably reduce the conservation time – taking it down to 2-4 days’ shelf time. Also, manufacturers may choose to inject a large proportion of CO2 to guarantee asepsis. It has the disadvantage of pushing the colour towards dark red, but increases the product’s shelf life by several weeks – normally from two to five.
For visual reasons, CO2-heavy packaging can use an opaque film to hide the undesirable appearance.
Meat and bacteria: what you need to know
Processed meat products can be decomposed by bacteria. These are normally different to those found in raw meat, as they have generally been introduced during the treatment phases (through drying or marinating, for example). Moulds are sometimes a desirable part of the process, in particular for dry-cured sausages.
The blend of gases in modified atmosphere packaging take this particular microbial spoilage profile into consideration, and require the necessary proportions of carbon dioxide and nitrogen.
