Meanwhile, back at the plant
The run of recent flexible-packaging advancements vis-à-vis cooking and heating is not limited to consumer-product packaging. Flexible packaging also is evolving for post-packaging pasteurization of cooked meat in the plant.
For ready-to-eat meat products, it is not uncommon to cook the meat and then apply a secondary operation within the plant, such as browning or smoking. However, that second touch-point makes the product vulnerable to bacterial contamination prior to packaging.
Post-packaging pasteurization, in which the completely processed protein is first packaged in a heat-shrinkable barrier bag and then heated to 200-205°F for several minutes, is used to reduce surface pathogens. This type of pasteurization can add up to two weeks of extra shelf life, a significant plus for the retail delicatessens that purchase this type of ready-to-eat product.
Until recently, processing techniques that created a rough surface on the meat were not compatible with post-packaging pasteurization because they poked holes in the barrier bag.
"There are some products that have a very abusive exterior. They might be coated in cracked peppercorn," says Mike Rosinski, marketing director for smoked and processed meats at the Cryovac div. (www.cryovac.com), Duncan, S.C., of Sealed Air Corp.
Another example is fried turkey breast. Rosinski explains, "With that flavor profile, they hold it in down in the fryer for longer periods of time and it comes out with a very hard, dried exterior. Those nibs or protrusions the come off the product can pop through a bag, particularly if it is rolling along a conveyor."
Cryovac's Heavy bag, here used by Crest Foods, is a heat-shrinkable, multilayer polyolefin bag that can be used for post-packaging pasteurization of products.
To address the issue, Cryovac developed an abuse-resistant barrier bag called the CNP310 Heavy bag. This heat-shrinkable, multilayer polyolefin bag can be used for post-packaging pasteurization of products such as open-rack cooked beef, brisket, fried turkey breast and items coated with roughly textured spices.
The Heavy bag runs on the same Cryovac rotary-chamber vacuum packaging equipment as regular heat-shrinkable bags, and at the same line speeds, to the benefit of processors with legacy equipment.
A separate development from Cryovac streamlines the handling of proteins that the processor cooks in a bag; after cooking, the bag is stripped off the product in preparation for further processing, packaging and, optionally, post-packaging pasteurization. Called the CNZ660 Grip & Tear cook-in bag, the package is made from a non-barrier, multilayer coextruded film.
The bag is designed with finger holes, a tear notch and a straight-tearing feature, allowing workers to easily strip the bag off the cooked product without a knife. Eliminating knives and other tools prevents repetitive-motion injuries and also reduces the possibility of product contamination. The primary applications for the cook-in bag are roast beef and cooked turkey sold in delicatessens.
Both in the plant and in consumers' homes, flexible packaging has come a long way toward achieving parity with other packaging materials when it comes to pasteurizing, cooking and reheating. You could say that films are just getting warmed up.