New system extends shelf-life

Cryovac Food Solutions has developed a high pressure sous-vide system for partially cooked chilled and frozen ready meals, which can extend shelf-life and cut cooking times using gentler heat treatment.

The firm is using it in conjunction with specially designed dual-layer packaging that incorporates minimal headspace between the first and second layers and can make contact with the food itself. The resulting products are more tender and nutritious and can be cooked more quickly than standard foods.

Dr Sidi Chouikhi, technical director, ready meals, Cryovac Food Solutions, told Food Manufacture: "If you reduce the initial cooking time, you can get better quality and this reduces the time by 20-30%."

Other systems, such as ultra-pasteurisation, often lead to high levels of condensation in packs, producing products with water floating on top of them, whereas Cryovac's system avoided this, said Chouikhi. "You also get better quality proteins [in products] because you have less water loss in the cooking process. [Commercial] customers are telling us you typically get 10% more protein than with traditional methods.

"In the usual process, the product is heated in a chamber under increased pressure," said Chouikhi. "In our system we apply pressure before we start heating, increase it to a much higher level, cool, then release the pressure."

The system was being tested by processors in the UK, but the market still remained resistant to extended shelf-life products, said Chouikhi. That was because they were still perceived to be of lower quality, despite the fact that the latest technological developments were overcoming these issues. However, he added: "We are looking at this with the number one chilled producer in one EU country."

Combined with Cryovac packaging concepts, the process can be used to deliver chilled or frozen meals that can be cooked in microwave, gas and electric ovens.