Food Packaging Climbs to the Summit

Samuel C. Prescott, LaVerne Clifcorn, C. Olin Ball, John Jackson, Philip Nelson, and Theodore Labuza—these past presidents of the Institute of Food Technologists all bear the distinguishing commonality of having been major participants in the research and development that has been the foundation of food packaging.

IFT co-founder Prescott was, of course, the pioneer in canning processes, followed by Ball, who also was one inventor of aseptic packaging. Clifcorn and Jackson were can company research executives, and Nelson is credited with the development of bulk aseptic packaging. Labuza and his colleagues developed the first predictive models for shelf life and also performed the seminal research on active and intelligent packaging, a topic I discussed at IFT’s 5th Research Summit, "Food Packaging Innovations: The Science, Current Research, and Future Research," held in Baltimore, Md., on May 7–9, 2006.

Topics of the summit included food quality and safety, encompassing some active packaging and food safety concepts; materials science and technologies, embracing polymer and bio-based nanocomposites; and sensing, touching on nano-biosensors and integrated microsystems. This is a powerful lineup of science and technology beyond the scope of most other contemporary food or food packaging conclaves.

Not for the first time in its long and honored history has IFT exceeded its audience’s expectations by reaching beyond the headlines in identifying and attempting to capture the mystery surrounding the bold new world of transmuting packaging from its current strength of protection and driving it into a future of intelligence and response. But, like its ancestry of thermal—and now nonthermal—microbiological control, barrier plastic, and hermetic closure, the next plateaus of connecting polymers and their brethren to molecular electronics will hardly be easy to reach.

Since a report on the summit being prepared for future publication will summarize the topics presented and present recommendations for future research needs in food packaging, I will focus here on a just a few of the high-technology innovations discussed at the summit that might influence food packaging thinking in the coming years.

The Landscape
Perhaps the most challenge with which we as food packaging scientists and technologists will have to contend is the changed consumers, perceptions, and channels around the world. In his role as organizer, co-chair, and newly elected IFT president-elect, John Floros of Pennsylvania State University overviewed the macroenvironmental variables influencing food and food packaging: population, ethnicity, age, economic disparities, politics, the racing technologies, climate, and a host of others that many scientists often overlook in their quest for knowledge.

Reemphasizing annual government data, Floros pointed out that food in the United States is the lowest-cost in world history, representing only 10.4% of disposable income—5.4 % for at-home eating and 4.7%, or nearly half, for away-from-home.

When asked, American consumers cite their desires and expectations from their food in the following descending order of importance: flavor (by far the most important aspect), convenience, health, safety, and "other."

Issues that seem to have an impact on food safety include microbiology, microorganism resistance to antibiotics, biotechnology, bioterrorism (which ultimately could affect consumer confidence and lead to social instability and food "insecurity"), globalization, new food processes, new food packaging, and "other" (which includes nutragenomics, biotechnology, materials, nanotechnology, and information technology).

Marketing appears to be entering an era of mass customization, offering and delivering food and other products not only tailored for specific target demographic or psychographic population segments but also directed at individual preferences.

And food marketing and its subset food packaging are faced with bipolarism, the contradictory realities and perceptions that food packaging must accommodate. Examples cited include global vs local, high technology vs high touch, new/improved vs traditional, ready-to-eat vs natural/unprocessed, low price vs premium price, and good-for-you vs naughty-for-you.

This "soft" marketing/sociological launch platform established a sobering perspective on the role of technology in the future of delivery of food, both protected by and potentially greatly influenced by its packaging.

And launch the assembly did, with just a few of the more intriguing (to me) topics highlighted below.

Composites and Nanocomposites
As printed and verbally reported ceaselessly in the trade and technical media, composites—and especially their tiny counterparts, nanocomposites—are predicted to represent our future in food and packaging, a perception that the summit probed for direction. Are nanocomposites a mechanism to enhance passive barrier, or are they a "yellow brick road" into a dramatic revolution in food product delivery? The summit participants explored the possibilities from perspectives beyond our food science and technology discipline.

• Nanocomposites. Pennsylvania State University’s Evangelos Manias highlighted the emerging realm of nanocomposites by defining them as having a size of 1–100 nanometers and behaving differently from the normal rules of physics we learned in universities. For example, water can become a "solid," or semi-conductors may change into insulators or good conductors. Among the measured property enhancements for host plastics are increased thermal stability, mechanical strength, and reduced gas permeability.

The challenge for nanocomposites in their interactions with host plastic substrates is that hydrocarbon polymers and the nanocomposite clays do not mix, so the clays must be modified using surfactants and the like.

The improvement in gas permeation of non-dispersed nanocomposite fillers is minor, but when the particles are oriented, permeability decreases. Exfoliated (meaning aligned) nanocomposites’ high-aspect-ratio long particles deliver meaningful improvements in gas barrier in plastics, due primarily to creating long tortuous pathways for the gas molecules diffusing through the plastic.

Among the commercial nanocomposite package materials—all of which are mixes with nylon MXD6—offered recently are those from Nanocor, Honeywell, Bayer for meat and juice packaging, UBE, and Unitaka. Interestingly, both Nanocor’s and Bayer’s packaging nanocomposite businesses have been sold this year. Reportedly, some beer bottles in Asia are three-layer, incorporating nanocomposites into the core layer.

Some reports have been published on inherent antimicrobial properties of the materials, and others have indicated good ultraviolet barrier properties.

• Bio-Based Nanocomposites. Amar Mohanty of Michigan State University’s School of Packaging discussed bio-based composites and nanocomposites in the context of incorporation into biopolymers defined on the basis of carbohydrate chemistry. Biopolymers of interest include polylactic acid (PLA), cellulose, PHBV, and starch. In pristine form, all have deficiencies that might be overcome by mixing with nanocomposites, much as fibers are applied in engineering plastics to improve various physical properties. Carbon nanotubes can be melt compounded or possibly incorporated during polymerization to overcome the immiscibility issues.

By incorporating nanocomposites into inner layers of multilayer structures, flavor barrier can be erected to overcome the increasingly visible problem of scalping.

Postulated were several intriguing possible benefits of nanocomposites in plastics, including flavor control and release and reduction of odors of corrugated fiberboard.

Sensing Technologies
Going beyond the enhancement of passive properties, nanocomposites have demonstrated the capacity to actuate polymers to perform responsively. The world seems to be linked with cellular communications—micro devices that are in some ways functional, in part due to nanocomposites. If cell telephones, why not packaging?

• Chips and Electronics. Georgia Tech’s Mahadeven Iyer drilled into this distant realm to expound that packaging to electronics engineers is integration of circuits, not protection of foods in distribution. Chips (electronic, not corn) are digitally converging from single function to multifunction, such as on the computer on which this article has been composed, to megafunctions such as biosensors. SOS is no longer an international distress signal, having graduated to signify "system on a chip" or in an (electronic) package by, for example, stacking chips to further miniaturize the total megafunctionality.

• Biosensors. Nanosystems integration encompasses a spectrum of bioelectronics that includes biocomputing, biosensors such as the electronic nose, and bioactuators. Biosensors basically incorporate a nano-input transducer to sense a biological variable, a nanoamplifier, and an output nanotransducer or signal generator, essentially a nano version of a conventional sensing/signaling circuit. Among the input transducers available, under development, or being considered are semiconductors, quartz crystals, microbalances, photodiodes, and thermistors—all familiar concepts in macro or even micro form but being targeted in nano size in the new research. These nano-size devices can be construed as laboratories on a chip, or on a carbon nanotube.

Examples of variables that are now or soon might be measured by nanobioelectronics incorporated into package structures are DNA, protein, peptides, spoilage microorganisms, enzymes, antibodies, etc., providing nanoscale high-sensitivity detection of target molecules. The objective is, for example, to detect and perhaps quantify the presence of pathogenic microorganisms via antigen–antibody reactions and subsequently signal that information to and through a radiofrequency identification (RFID) device. We can readily postulate that the output signal may be applied to a control device such as a package-rejection mechanism or a temperature-reduction switch.

An Incredible Journey
We have traversed an incredible journey from the food packaging pioneers of the past who labored in the visible macro world of food particles and liquids—and who led us into packaging protective mechanisms and barriers to aid in food preservation—to those of us who refined and further quantified their principles to permit us to touch the surface of intelligent and active packaging.

Now, being handed to us from the mysterious universe of 10^–9—which might yet alter our entire perspective of molecular mechanics—is nano. This contemporary "buzz" word that dazzles and intrigues so many might be a portal to a bold new world of intelligent and active packaging that transmutes our food packaging into a vibrant active food protection mechanism.

So far, nanotechnology applications have been another tool in our pantry of packaging technologies. Our exposure in this "summit of summits" from outside our conventional wisdoms (i.e., the scientists from nano) suggests manipulations of polymers to leap far beyond a next generation into what might be a total revolution in food packaging history.

I commend IFT and its summit concept for again displaying the vision and courage to lead us to what might well be a giant step for food packaging.

by Aaron L. Brody,
Contributing Editor,
President and CEO, Packaging/Brody, Inc.,
Duluth, Ga. 
[email protected]