Research into new renewable options

Photos courtesy of Natureworks LLC.
Polylactide polymers are generated from a starch such as corn and ultimately form an assortment of plastic products. A polylactide tray can be composted, incinerated or placed in a landfill for ultimate decomposition, and is compatible with existing recycling systems. NatureWorks trays are made with plastic created from plant starch, such as corn.

For most growers, packaging for their products is an important concern. Cost, environmental considerations, product stability and shelf life all play into the choice. With the unpredictable cost and availability of petroleum-based packaging comes an impetus to develop alternatives.

The advent of bio-based and renewable packaging gives growers more choices and the potential to reposition themselves to market their crops in innovative ways.

The move to renewable packaging sources

The Sustainable Packaging Coalition (www.sustainablepackaging.org) is an industry group working to make packaging more beneficial to the economy, population and environment. It envisions packaging as something safe and beneficial, while meeting market standards for performance and cost. It promotes packaging created from renewable or recycled materials and values the use of renewable energy in the entire process from sourcing to recycling.

In Europe, limited landfill space has forced a reduction in over-packaging and a move toward renewable containers. Similar concerns in the United States, along with petroleum worries, consumer demand and heightened environmental awareness, are bringing the trend here. In addition, American growers who export their products may be subject to their clients’ requirements. Although time and experimentation are needed to create optimal choices, a move toward greater use of natural sources has the potential to keep growers working the land.

Courtesy Natalie Scott, Michigan State University.
Almenar, right, and a graduate student examine the microbial activity of different types of food over time in different types of packages.

What is it?

Dr. Eva Almenar of Michigan State University’s School of Packaging says environmentally friendly packaging is an umbrella term that includes materials, technologies and environment. Different aspects, such as recycling, compostability, energy savings, biodegradability, and packaging reduction and reuse, as well as different materials such as paper, glass and plastics, all figure into the overall concept. When growers and others make packaging selections with an eye to environmental safety, it isn’t simply a matter of choosing paper over plastic. What energy is consumed in manufacturing and disposing of or recycling the container? Is the package biodegradable or compostable?

Bio-based and renewable packaging refers to those materials drawn from natural sources, such as corn expressly produced for use in packaging and waste materials from other crops that can be reused. Natural sources are readily renewable, unlike options such as petroleum. Today, plastics, fibers and other materials are created from renewable sources.

Photo courtesy of Natureworks LLC.
NatureWorks clients can choose between corn source options: no genetic content polymer, an off-cost between genetically modified and standard corn, and a seed-to-finished product identity-preserved product class.

Considerations

Almenar says misconceptions about the newer packaging types muddy the waters. A plastic derived from a renewable origin isn’t necessarily biodegradable or compostable. Not all materials that are biodegradable come from natural sources. The ability of the item to break down naturally is determined by its chemical structure, not its origin. Thus, considering the life cycle of a package helps someone evaluate how environmentally friendly it actually is. A life cycle analysis looks at an item from inception to final disposal and determines its overall environmental impact.

Today’s choices

Today’s packaging choices include disposable, reusable, recycled and renewable containers. In addition to petroleum-based plastic products such as clamshells, corrugated boxes created from recyclable materials are on the market. Maxco Packaging (www.maxcopackaging.com), for instance, manufactures corrugated containers from renewable paper (without wax) and water-based inks.

Cascades Forma-Pak has developed 100 percent recyclable mushroom packaging made entirely from old newspapers and phone directories. The Canadian firm says its product keeps 1.5 tons of paper out of landfills every day.

Earthcycle (www.earthcycle.com) is another Canadian company offering packaging created from a waste material, palm fiber. Typically, palm fiber, said to compost in less than three months, is incinerated as garbage when oil is extracted from palm fruit. Its produce containers are used at several large U.S. supermarket chains. Earthcycle offers a variety of packaging coverings, including NatureFlex film made from wood pulp cellulose, netting and plastic lids. NatureFlex is manufactured by Innovia Films (www.innoviafilms.com).

Another well-known bio-based packaging choice is polylactic acid (PLA), a rigid plastic derived from a natural starch such as corn. Cellulose and thermoplastic starch are additional options. Starch is inexpensive and easy to break down, but is water-sensitive and poor mechanically. Polyhydroxyalkanoates (PHA) currently have few commercial applications due to the material’s high cost.

NatureWorks LLC (www.natureworksllc.com), a joint venture between Cargill and Teijin Limited of Japan, is a brand offering PLA produce containers. The company says the product is made with 65 percent less fossil fuel than traditional plastics and has a range of reuse options. NatureWorks plastics may be incinerated, composted or placed in a landfill for ultimate decomposition (it is unclear if decomposition is suitably efficient), and are compatible with existing recycling systems. Some object to the company’s use of genetically modified corn, which the firm answers with options eliminating or offsetting altered sources.

Almenar says all current bio-based choices have several common weaknesses, including poor barrier properties and thermal resistance, and they are costlier than some traditional materials. She adds that collection and recycling systems for these products need improvement; companies such as NatureWorks are developing innovative methods to combat that problem, such as a buy-back program for large recycling operations. On the plus side, the available biopackaging types are formed from renewable sources and can be recycled or composted and are biodegradable. They are proven safe for food use and support a move away from petroleum-based materials.

Tomorrow’s products

Almenar is involved in developing bio-based packaging with a special interest in prolonging shelf life. She has evaluated the use of microperforated and continuous films, bags and packages for fresh produce. She says that processes such as equilibrium modified atmosphere packaging (EMAP), modified atmosphere packaging (MAP), controlled atmosphere packaging (CAP), active packaging (AP), coatings, and the use of antimicrobial volatiles are effective in maintaining quality. Such processes manipulate the internal atmosphere to a composition most favorable to the food contained. Ultimately, the work of Almenar and other packaging scientists will yield new bio-based, renewable packaging that maximizes product life.

Those types of containers will not only offer growers expanded packaging choices, but may lead to new market opportunities. Farmers will be needed to meet the increasing demand for plant-based sources. Compostable products have the potential to be returned to the fields as fertilizers and soil conditioners. Developing and deploying such strategies will require additional research, however. Still, the day may come when growers produce both the food we eat and the container it’s purchased in.

Learn more about sustainable packaging online:

Ohio State University BioProducts Center: http://www.bioproducts.osu.edu
Michigan State University School of Packaging: http://www.packaging.msu.edu
Paperboard Packaging: www.paperboardpackaging.org
Buckhorn reusable plastic packaging: www.buckhorninc.com
Corrugated Packaging Council: www.corrugated.org
World Packaging Organization: www.packaging-technology.com
University of Florida: http://www.ifas.ufl.edu
University of Illinois: http://www.age.uiuc.edu
North Carolina State University: http://www.ncsu.edu
Purdue University: http://www.purdue.edu

Based in Greensboro, N.C., the author writes articles about horticulture, landscaping and agriculture. She has been a contributor to Moose River Media publications for three years.