First used by the US pork industry around 1983 primarily for producing boiled hams, cook-in packaging technology has expanded among proteins and greatly evolved. Cookin materials include cook-in (shirred) casings; pre-made bags; and the most widely used method – thermoform rollstock materials.

“We have introduced more and more [cook-in] materials to processors who are coming to realize the benefits of cook-in technology,” said Mike Rosinski, Sealed Air’s Cryovac brand marketing director for smoked and processed meats. “We have applied it in more areas. Poultry processors have become a much larger part of the industry. Most deli turkey products are cooked in cook-in material.”

Dakota Provisions, Huron, S.D., is a heavy user of such technology, says Chet Coolbaugh, director of operations. Dakota Provisions turkey processing plant processes poultry and other protein products specially designed for retail and foodservice customers. As a percentage of readyto-eat products, the company’s breakdown in usage of cook-in packaging technology is cook-in casings , 86  percent (1.143 million lbs./wk) and rollstock type , 14  percent (0.186 million lbs./wk).

“The benefits [of using cook-in packaging] are it minimizes loss in yield; preserves shelf-life, particularly for plastic, non-permeable material; facilitates better production planning; and it ensures food safety,” Coolbaugh says. “About 15 percent of products are sold and shipped in logs using cook-in casing.”

Proliferating in use
Even in cases where the hams are not in cook-and-ship, chances are the ham was cooked in a package and the packaging was removed in-plant so the product could go through a subsequent browning or colorization step, Rosinski says. Cook-in technology is also widely used for producing roast beef for foodservice and retail. “Your basic split-top round roast beef product bought in the deli is generally cooked in a cook-in material,” he adds. “Many of those same products that go into the retail fullservice deli also go through the foodservice channel to major foodservice distributors like Sysco and others to massfeeding establishments.” Processors of all sizes use cook-in technology. “[This technology] is employed widely for producing any kind of precooked protein used as an ingredient in soups or on salad bars or in convenience foods like frozen pizza or fajita meat,” Rosinski says. Sealed Air/Cryovac has been building its portfolio of cook-in materials for the last 28 years and offers a wide range of rollstock materials, bag materials and casing materials for cook-in applications, Rosinski says.

Cryovac’s new Grip & Tear technology includes CNZ 660, a bag for industrial cooking applications where the processor removes the bag after cooking and further processes the product. The Grip & Tear feature enables the processor to remove the product in the plant without using a cutting utensil, Rosisnki says. “That improves worker safety and food safety,” he adds. “When cutting the bag away with a cutting utensil, they often cut into the product and scar it. That creates a visual defect and an opportunity for product-to-product contamination.”

The company also offers a CNPZ310 Grip & Tear post-pasteurization bag. After packaging a product, the processor sends the product through a short-time but high-temperature thermal process to reduce surface bacterial counts. That barriermaterial package goes to either a foodservice channel or to the retail deli.

Sealed Air/Cryovac also just launched a new high-abuse, postpasteurization bag called CNP 310 Heavy. Many of the products that go into post pasteurization went through some type of a surface coloration or other treatment after cooking, Rosinski explains. Such treatments render the product with a fairly coarse surface. Oil frying, for example, leaves a crusty, rough surface, which is common with deli turkey products. Therefore, many of these products require an abuse-resistant bag.

The thermal processing and subsequent cooling process of post-pasteurization also adds some abuse through handling of the product. This bag joins the CNP 310 to complement that offering for higher-abuse applications.

Finally, the company also offers a family of ovenable cook-in products currently being launched under the Oven Ease brand. These cook-in materials are intended to allow either a retail, foodservice establishment or consumer to reheat the product or cook it from raw in a conventional oven to temperatures up to 400°F.

“With the Oven Ease products, the processor can cook the product in his plant, chill it down, distribute it and the end-user can reheat the product in a conventional oven,” Rosinski says. Curwood Inc., Oshkosh, Wis., is seeing some increase in demand for cook-in materials. “With the current economy, people are eating at home more and using more prepared foods at home,” according to Brian Conrad and Pete Bruehl, marketing managers. “This trend may be driving more demand to the pre-cooked products at retail at the expense of fresh or frozen meat products in foodservice.”

One cook-in benefit is the shrink bag or thermoformed package can act as a pan/mold liner. “The product is cooked in the package and the pan/ mold stays clean during the cooking process,” Conrad and Bruehl say.

Cook-in packaging can also feature adhesion properties so the protein binds to the bag/film and keeps the moisture in the product rather than evaporating during the cooking process. Yield is improved as a result.

Curwood offers three cook-in shrink bags: Cook-Tite 76, Cook-Tite 76A and Cook-Tite CS bags.

Cook-Tite 76 bags are cook-andship bags. These bags are typically used for whole-muscle products like roast beef. Cook-Tite 76A bags are also cook-and-ship bags with adhesion properties. They are used for meat slurry products like molded turkey and ham products. The adhesion properties allow the protein in the slurry to bind to the bag and keep the moisture in the product rather than leaking out after the cook process.

Cook-Tite CS bags are for cookand-strip applications. The bag is stripped off after the cooking process and the processor adds additional value to the product by applying surface coatings or slicing the product. The product is then repackaged in the final package that is sent to the retailer or foodservice customer. 4x6 lunchmeat hams are a typical product that uses Cook-TiteCS bags. Curwood also offers forming and nonforming films with and without adhesion for thermoforming applications.

Some additional cook-in capacity is being added in the processed meats market segment, particularly in the smoked sausage area, Curwood’s Conrad and Bruehl say. “Cooking the product in the final package allows our customers to eliminate the potential for surface bacterial contamination of the product occurring by handling the product after cooking,” they add. “By keeping the bacterial counts low, shelflife is improved. Processors also don’t need to use as many preservatives to achieve a longer shelf-life, and they can promote a simpler label as well.”

Curwood also sees a trend toward peelable packaging used in the processing plant. Making it easier for the processor to strip the cook-in package from the product helps with ergonomics and safety in the plant, besides preventing cross-contamination from using the same knife to cut open the packages.

Sealed Air/Cryovac’s Rosinski expects cook-in technology use to continue growing. “The reasons for this expected growth includes improved efficiency, safety, shelf life and convenience for foodservice operators and consumers; labor reduction; and it has a role to play in some of the reformulation efforts you see processors working on today to reduce preservatives,” he concludes.