Inside the Food Package

Photos by Jacob Lewkow

Although it is one of the last steps in production, a food’s packaging can be the most critical aspect of its safety and quality. But, in addition to simply protecting the food within, today’s food packaging materials are being asked to extend shelf-life, increase or decrease the food/packaging interaction, and/or be more sustainable and cost-effective — while still being attractive to customers. It is just such packaging fundamentals, improvements, and innovations that drive the Michigan State University School of Packaging.

While the school focuses on packaging of all kinds, about one-half of all packaging manufactured is for food and beverage, said Professor and School of Packaging Director Susan Selke. So this is a primary focus of the school, whose research includes that which is funded by the university and by sponsorships, as well as that conducted directly for companies that pay fees for the university’s research. In fact, the school has worked with a number of food and beverage businesses to solve problems or innovate new packaging.

Established as a discipline in 1952, Packaging become an independent school within MSU’s College of Agriculture and Natural Resources in 1957 to be the first of its kind. Still a pioneer in packaging innovation, the school was ranked as The Best Packaging Science College of 2017 by Universities.com, and is the only one that offers a Ph.D.

In QA’s visit, the school’s purpose of “creating and advancing knowledge in the science of packaging through innovation, sustainability, and stewardship” was immensely evident, with bio-based material research at the core of multiple food-packaging projects. But, while such materials are often beneficial, they are not the simple answer for all foods.

SUSTAINABILITY. “One of the things we get into conversations with people about is making sure companies understand the decision they are making with sustainable packaging,” Selke said. There is a lot of marketing hype, such as “plastics bashing,” pushing manufacturers toward sustainable packaging. But, she said, you need to look at the whole life cycle of the food and its packaging to make an intelligent decision.

Sustainability is a relative term. A plastic bottle or bag may not be seen as meeting the consumer definition of “sustainable,” but if it means decreased food loss through lengthened shelf-life or reduced weight in transportation, it can be environmentally advantageous because less food is trashed or transportation fuel consumption lowered. “You really have to look at the whole system,” Selke said.

Additionally, the biodegradable aspects of food and its packaging are not well understood. “Companies want biodegradable packaging, but the food, itself, doesn’t degrade very fast,” Selke said. She cited the research of Rubbish!: The Archaeology of Garbage author William Rathje, who, in digging up landfills found that there is a great deal less biodegrading than one would expect. In fact, he found decades-old hotdogs, lettuce, corn cobs, and bread rolls still intact and easily identifiable, alongside dated newspapers and other biodegradable trash.

Moisture content is the primary factor for decomposition, but Selke said, modern landfills are well-constructed — designed to prevent water ingress — so all of it will degrade slowly. Thus, if a food manufacturer uses biodegradable packaging, but “the end of life (for the food) will be a landfill, then they’re not accomplishing what they think they are,” she said.

Also playing into this is consumer perception of biodegradable and composting which can add to littering. “Consumers think being biodegradable is a green check to litter,” said Associate Professor Rafael Auras. “So a behavior change needs to happen.”

All this is not to say that we should not be seeking to reduce the environmental footprint of non-sustainable packaging, but manufacturers need to consider many more factors in making such decisions.

PACKAGING FOR LONGEVITY. It is for such reasons that MSU’s School of Packaging researchers are studying and innovating bio-based packaging that also preserves and/or increases food quality and shelf-life. One such study is the research Auras is conducting for NASA on packaging that preserves or increases food quality and shelf-life but is composed of bio-based, biodegradable, compostable materials to be disposed in places that can be composted. The research focuses on food safety and quality as well as sustainability, which considers both recycling and composting. “If packaging can be cleaned, it is good for recycling; but if it can’t be cleaned, it should be able to be composted,” Auras said.

The school has been conducting significant research on the development of compostable technologies, installing chambers which are environmentally controlled to simulate the time and temperature of a compost pile. As materials break down, they release carbon dioxide and researchers capture and measure the amounts of material converted to CO2. Up to 120 jars of material can be tested in its two chambers.

Versatility is necessary because many food products need to be packaged in materials that create a barrier against oxygen and moisture, for which plastic materials are currently one of the best options. Reiterating the points made by Selke, Auras said, “Packaging is important, but if the packaging isn’t doing its job, there will be a greater environmental footprint made from food waste. We need to protect the value of the food.”

At the same time, to reduce the environmental impact of packaging — including the build-up of plastics in the ocean, we need to develop better waste management systems on a global basis, he said. Research such as Auras’ NASA project shows the extent to which decisions on packaging need to focus on the characteristics of the food and the conditions to which it will be subject, along with consideration that “the environmental relationship of packaging to food should be no more than 10%,” he said.

The U.S. is, in fact, behind some other nations in such aspects of food packaging. Auras cited Japan as an example where foods may have a shelf-life as high as 10 years. A higher value is placed on protecting the food, with the understanding that the longer it can last, the less waste there will be.

IMPROVING BARRIER PERFORMANCE. Another area under development by the school’s Associate Director and Professor Laurent Matuana and his Ph.D. student Sonal Karkhanis is that of packaging for ready-to-eat meats as well as fresh-cut fruits and vegetables.

The research is seeking to replace current crude oil/petroleum-based packaging materials with a bio-based and biodegradable polylactic acid (PLA) material that also would provide long shelf-life. PLA currently lacks barrier performance against water and oxygen which cause spoilage. “If we can improve the barrier of the bio-based plastic and delay the permeation, we can delay the growth of microorganisms,” Matuana said.

To keep the bio-based biodegradability of the material but extend its barrier properties, the researchers have added cellulose nanocrystals (CNCs) from trees, particularly those which have been burned in forest fires. For the research, the CNCs are being extracted at the USDA Forest Products Lab in Madison, Wis., in collaboration with Ronald Sabo and Nicole Stark.

Even though CNCs are nanoparticles, they can impart valuable properties, and they are compatible with other bio-based materials, Matuana said. From that research, the team has developed a film with one percent CNCs, which has improved the barrier characteristics of the film by up to 50% for water and 75% for oxygen. Their research is now focusing on the extent to which it is improving the shelf-life of food, with the first test using water-sensitive saltine crackers.

Thus far, the team has found that even when exposed to 99% humidity, the food packaged in CNC-impregnated PLA films is three times as shelf-stable as the one packaged in PLA alone. Additionally, as a natural product, the CNC PLA is very safe. Toxicology studies have shown it to have no cytotoxicity, and both the pharmaceutical and food industries are looking into its use.

STUDENT RESEARCH. While the school’s research is being led by its faculty, graduate and upper-undergrad-level students are very involved in the work. Associate Professor Eva Almenar’s main work is on the development of packaging materials from renewable feedstock, with a focus on active packaging materials for the produce quality and safety. Working with her on an array of projects to extend the shelf life of foods through bio-based materials and active packaging that interacts with the food product are masters students Dylan Spruit, Jack Fehlberg, and Pramit Sawand; dual enrolled masters/undergraduate student Jennifer Le; and senior undergraduate Sydney McKay.

• Spruit’s research focuses on a market-study comparison of e-commerce packaging against traditional packaging and potential new developments sponsored by UBE Inc. As an undergraduate researcher, Spruit worked with Almenar on completing a study of the water sorption characteristics of active packaging compounds. He interned at J.M. Smucker, testing packaging and conducting shelf-life studies.
• McKay is studying material release from the perspective of microbial kill. She is currently determining the inhibitory concentration of the active compounds prior to their mixing with the polymer matrix. McKay interned at General Mills, collaborating with food scientists to ensure packaging matched the food.
• Le is focusing on byproducts and the extension of shelf-life through the mixing of these with polymers to develop innovative packaging to reduce oxidation in food products. Le interned at Pepsi, working with the packaging group on new product launches and distribution testing.
• Fehlberg is studying the reuse of agricultural waste in packaging including the production and assessment of new packaging to extend food shelf-life. As an undergraduate researcher, Fehlberg collaborated on some of Almenar’s ongoing projects including research on the use of a coating material to control fungal growth on blueberries, the efficacy of absorbing pads on reducing microbial growth in packaged food, and the thermal and optical properties of protein-based polymers.
• Sawand’s focus is on the use of the thermoforming technique to form waste into food packaging and evaluation of the resulting trays.

Each of the student’s works builds on that of the others — and others that have come before. “It takes years to do the research, so different people work on each step,” Almenar said. With her background in food science, she is able to provide an in-depth understanding of the foods as well as the packaging. This is important because different foods spoil because of different interactions. For those subject to spoilage from oxidation, the development of oxygen-removing packaging is most effective; whereas produce is most likely to be contaminated by fungal growth, so antimicrobial packaging needs to address that. “You first need to know the food, then develop the packaging,” Almenar said.

Beyond that, there also needs to be an understanding of where and how the food will be marketed and what it will be exposed to, she said. Taking all this into consideration, the group’s research then focuses on the potential of bio-based materials to preserve food and reduce waste. That is, she said, “How can we use things that are growing in nature while reducing food waste as well?”

THE SCHOOL. To get students to the point of conducting such research, a foundation of knowledge needs to be laid. Thus, the School of Packaging study begins with the classroom study of basic principles of physics, chemistry, mathematics, and materials science, along with specialized courses, such as food packaging. Students then participate in labs to create packaging materials with a focus on the speed and temperatures of the compounds and resins for the film; cutting, shaping, molding and measuring it in the right proportions to produce bottles, pouches, etc.; and conducting testing throughout. Such testing may include that of the environmental, production, and transportation impacts on the materials and packaging. To further their real-world knowledge, students operate actual food-processing equipment to simulate the processing and packaging of food and drink. “Currently they are separate machines, but the goal is to have all as mobile units, so various line configurations can be set up to simulate production plants,” Selke said.

The school has two full corridors of labs. Unlike many universities, the labs are not specific to a single researcher or professor, rather, Selke said, they are set up as shared space organized by function. This not only enables coordination of the work but provides for efficient utilization of space for students to work with and understand the functioning of the major types of equipment, and how they interact. Just a few of the lab areas in the school are the shock and vibration lab, filling lines, environmental chambers for different storage conditions, analytical chemistry lab, tensile tester, retail-simulation area, and materials labs.

Additionally, as demonstrated by the internships of Almenar’s team, “more than 90% (of the packaging students) will have had at least one six-month, paid internship by the time they graduate,” Selke said. “Increasingly students are doing two internships.”

CONTINUED GROWTH. Since its 1952 origination, MSU’s School of Packaging has undergone a great deal of change and growth. Prior to Selke’s current role of director, which she took over in 2015, she was interim director from 2007 to 2009. One of the greatest differences she sees from then to today is the increased use of plastics and more complex structures. “A lot more pouches are being seen,” she said. “A lot of it is driven by cost, but that shows up in different ways.” For example, the use of plastic instead of glass eliminates weight and potential breakage and increases consumer convenience. Additionally, she said, as a relatively flat surface, “it’s a better billboard” for marketing.

In fact, shortly before Selke took over as director in 2015, the school undertook significant strategic planning. With enrollment increasing, a number of faculty retiring, and several years of no new tenured faculty, the school was having difficulty maintaining both its instructional and research requirements. “Despite some limitations on enrollment, we were growing beyond capacity,” Selke said. “We are a research-intensive land-grant university, but we didn’t have time for research because there were so many students we needed to teach.” So the school made its admissions requirements more stringent, and has hired three tenured faculty within the last three years.

The strategic planning also gave the school an opportunity to take a reflective look at itself and where it is going. “As the first school of packaging, we feel an obligation as stewards of the discipline,” Selke said. There are other packaging schools, but MSU is looked up to as having been first and has been ranked as best. To continue to hold that top spot and fulfill her own dedication to helping others and making a global impact, Selke said, “My main goal is helping develop the people who will be leaders in packaging and industry.”

The author is Editor of QA magazine. She can be reached at llupo@gie.net.