The latest generation of flexible packaging has a pervasive theme: convenience. Pouches and bags for foods in a variety of categories showcase refinements in ease of package handling and opening as well as product access and preparation.
A novel sterilization technology for flexible packages that provides an alternative to retorting achieved new status this year when the FDA accepted a petition for the commercial use of the process for low-acid foods. The technology is known as pressure-assisted thermal sterilization (PATS).
PATS combines mild heat with high pressure to produce commercially sterile low-acid food products in shelf-stable pouches. In development for seven years, the technology has undergone a rigorous validation process and safety assessment in the past two years. The PATS development and validation efforts are the work of the National Center for Food Safety and Technology (www.ncfst.iit.edu), Chicago, and NCFST’s Dual Use Science and Technology (DUST) consortium.
Members of the DUST consortium include scientists and engineers from ConAgra Foods, Hormel Foods, General Mills, Basic American Foods, Unilever, Mars Co., Avure Technologies Inc. and the U.S. Army Natick Soldier Research, Development and Engineering Center. Avure (www.avure.com), Kent, Wash., manufactures the pressure vessel used for PATS processing.
The key benefits of the process are food safety and product quality. PATS significantly improves the quality of thermally processed foods while eliminating the safety risks associated with bacteria such as Clostridium botulinum.
The test product and packaging used to validate the PATS process for the FDA filing was 5 oz. of mashed potatoes in a pouch made from a multilayer flexible material incorporating PET and nylon.
During reheating, “the potatoes smell like potatoes cooking on your stove, and they have that color characteristic as well, because you haven’t caramelized the sugars” during sterilization, says Larry Keener, DUST validation team leader and president of Seattle-based International Product Safety Consultants (www.foodsafetyprofessionals.com). IPSC worked with NCFST to establish PATS validation procedures, protocols and testing.
“PATS is a revolutionary technology that will deliver quality meals with higher nutrient retention, something that is not quite possible with current thermal processing methods,” says Jorge Succar, director-process engineering, ConAgra Foods (www.conagrafoods.com), Omaha, Neb.
It is too soon to say which products ConAgra will produce using PATS. “However, we’re looking at a full-range of products — everything from complete, shelf-stable meals to easy-to-prepare side dishes,” Succar says. Acknowledging that the technology is still very new, he says ConAgra hopes to implement PATS “within the next couple of years.”
Currently, PATS demonstration product is being produced on behalf of the U.S. Army, which will perform organoleptic testing, ship testing and some sensory testing.
IPSC’s Keener says the goal is to “prove the proposition that this is a better tasting offering than the conventional MRE [Meal, Ready-to-Eat].” MREs are military field rations. If the Army’s current tests go well, mass production of PATS-processed MREs will follow.
Consumer demand for fast, easy cooking continues to be a major driver. In the frozen-foods segment, H.J. Heinz Co. (www.hjheinz.com), Pittsburgh, opted for a flexible package with steam-in-pack functionality for its new line of frozen mashed potatoes. The launch represents Heinz’s first use of a steam-in-package structure, a package concept that has rapidly gained momentum in the past two years.
Heinz’s Ore-Ida Steam n’ Mash product line, which includes four flavors, launched last summer. Each 24-oz. package holds seven servings of real potatoes that have been scrubbed, peeled and chopped. After microwaving the potatoes, consumers mash them using whatever additional ingredients they prefer.
The potatoes “go from freezer to table in less than 15 minutes. Just steam the bag in the microwave, add milk and butter and mash them your way,” says Heinz spokesperson Tracey Parsons.
Alcan Packaging (www.alcanpackagingfood.com), Chicago, produces the bags, which are made from a laminate of polyethylene terephthelate (PET) and polypropylene. A high-performance sealant on the interior of the laminated film enables the packaging material to perform well in the full range of temperatures associated with frozen distribution and microwave cooking.
The Ore-Ida Steam n’ Mash bag’s self-venting feature is created using in-register laser technology. The integrity of the product and package are maintained until the heat of the microwave causes pressure to build inside the package and press it open.
For consumers, the product benefits are ultra easy product preparation and the taste (and psychology) of scratch cooking. “The Ore-Ida Steam n’ Mash launch was intended to tap into a key consumer insight of making homemade mashed potatoes that are easy enough to make every day. Now more than ever, busy moms need convenient ways to make nourishing meals their families love,” Parsons says.
The package performs well from a marketing perspective, as well. The bag billboards the Ore-Ida Steam n’ Mash brand in the freezer case using seven-color printing and high-impact photography of the product.
Heinz also chose flexible packaging when launching another frozen product line: T.G.I. Friday’s Complete Skillet Meals. As the name implies, the products cook on the stove top.
Formulated using the signature flavors of T.G.I. Friday’s restaurants, such as Firecracker Sesame Chicken and Cajun-style Alfredo Chicken and Shrimp, the meals take three steps to prepare and cook in about 15 minutes. The product line includes five varieties, and each package serves two.
The product’s ingredients, such as chicken, vegetables, pasta and toppers (sesame seeds and bacon bits) are individually packaged in bags within a larger stand-up pouch. As with the Ore-Ida Steam n’ Mash package, the pouch offers a billboard for branding and graphics. Alcan supplies the stand-up pouches.
Easy to open, easy to eat
In other categories, brand owners are opting for packaging with easy-open features that make portion control and product access easier. For its Galaxy Mistletoe Kisses confection, the Brussels, Belgium-based European division of Mars Inc. (www.mars.com) chose a flow-wrap package that can be opened anywhere along the length of the wrapper.
The serrated edge of the back seal creates a series of tear initiation points along the longitudinal edge of the package. Thus on-the-go consumers can easily share the product or save part of it to eat later, all without touching the product.
Each Mistletoe Kisses pack contains three pieces of chocolate, so the package design is well suited to the product. Amcor Flexibles (www.amcor.com), Brussels, provides the package, which it calls Amcor ZigZag.
Also in Europe, a stand-up pouch designed with a wide opening for easy product access is finding applications for snacks and produce. United Kingdom retailer Sainsbury’s (www.sainsburys.co.uk), London, England, recently launched its private-label fresh blueberries in the wide-mouth package.
As interest in new flexible package formats continues to grow in the frozen food category, film suppliers are exploring ink technologies that add value for these packaging applications. One area of inquiry is thermochromic inks, which change color, appear or disappear based on temperature.
“We work with our ink suppliers to develop ink formulations,” including thermochromic inks suited to flexible substrates, says Lani Craddock, vice president-marketing at Exopack LLC (www.exopack.com), Spartanburg, S.C.
With this technology, she explains, “a logo or instructions on the package would show up based on the temperature,” becoming visible when the package was removed from the freezer or after heating in a microwave oven. The technology also has applications for contests and promotions, making it possible to temporarily conceal on-pack game pieces, instant-winner alerts and coupons.
The stackable pouch features a top and bottom gusset; the top gusset is scored on the interior of the package. To open the pouch, the consumer applies pressure along the score line and pushes the sides of the top gusset to the sides of the pouch. The blueberries can be consumed directly from the pack, and they may be washed in the package thanks to holes incorporated in the bottom of the pouch.
This package format, called the PushPop, is produced by Amcor. Other European brand owners are using the PushPop, sans bottom holes, for snacks such as dried fruit and nut-and-fruit mixes and even for heat-and-serve meatballs.
For on-the-go products that are best consumed hot — or cold — a new flexible packaging material has been developed with insulation in mind. The film, created by Innovia Films Inc. (www.innoviafilms.com), Atlanta, and sold under the name Rayotherm, holds promise for food and beverage packaging as well as industrial applications. The film is made from bi-oriented polypropylene.
Applications for the film include formed packages, wrap-around labels, in-mold labels and thermoformed labels. According to the supplier, the film is compatible with sealing, printing, embossing, die cutting and machining.
In addition to keeping food hot or cold, packaging made from the film would insulate consumers’ hands from the temperature extremes of items such as ice cream, soup and hot beverages.
