The speed at which ready meals go bad depends on the ingredients; this differs greatly from product to product. In the case of ravioli or lasagne, which contains meat, the meat naturally goes off quicker than the pasta itself.
One of the largest challenges in ready meals is the prevention of bacterial contamination during the production process. In order to achieve this, manufacturers must work in accordance with the highest possible hygiene standards and with ingredients of the best quality.
Decay is mainly caused by the growth of micro-organisms, oxidation and food becoming stale. This results in rancidness, discolouration and loss of flavour. For example, a fresh pizza that is exposed to air of 4°C to 6°C will go off within a week. In the right protective atmosphere with a low level of oxygen content combined with a high level of carbon dioxide concentration, a pizza can keep for weeks. In the event of a pizza, the O2 concentration must be below 1%.
The proportion between the amount of carbon dioxide and nitrogen in ready meal packaging is mainly determined by the moist content in the product, as well as by the composition thereof. This is because this determines the speed of bacterial growth, oxidation and enzymatic activity. The higher the water activity, the higher the required CO2 concentration in the packaging.
The specific requirements for products of different components
Every ready meal comes with its own specific challenges. Nutrients of a neutral pH value are particularly vulnerable in this respect. Particularly products with a wide range of (changing) ingredients (such as sandwiches, filled pasta, salads, pizzas and spring rolls), opting for the exact right solution may be difficult.
Since every ingredient has its own specific properties, in-depth expertise of foodstuffs is required in order to compose the gas mixture that combats decay most effectively and which offers maximum protection in terms of quality.