Extending the shelf-life of a product & keeping it fresh is a contradiction in consumers’ minds

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NanoPack packaged bread. Photo: NanoPack.

‘Active food packaging’ offers increased food safety, extended shelf-life, improved freshness and reduced food waste, but the idea of a product with a long shelf-life and being fresh is a contradiction to some, according to researchers.

A team working on NanoPack, an EU-funded project, under its Horizon 2020 research and innovation programme, has published the results of a study it did to find out what consumers and retailers think about active food packaging technologies.

Antimicrobials

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NanoPack food packaging films can extend the shelf-life of foods by inhibiting microbial growth, improving food safety and reducing food waste. The team is working on a pilot line to 'manufacturer functional polymer nanocomposites from natural halloysite nanotubes (HNTs); demonstrating controlled release of antimicrobials in food packaging applications'.

Active food packaging, or nanotechnology, includes anything from antimicrobial polymer films, HNTs, retardation in oxidation, hindered respiratory process, prevention of microbial attack, prevention of moisture infusion, use of CO2 scavengers/emitters, ethylene scavengers, aroma emitters, time-temperature sensors, ripeness indicators, biosensors and sustained release of antioxidants during storage. 

NanoPack organized 10 focus groups and 10 interviews with consumers and retail managers in China, Spain, Italy, Denmark and Ireland to conduct the survey.

Polymeros Chrysochou, associate professor, marketing and consumer behavior, Aarhus University, Denmark, who, together with Alexandra Festila, assistant professor at the same university conducted the research, and said the findings revealed consumers were not concerned with ‘nanotechnology’ but the inclusion of essential oils and the ‘active’ nature of this technology, which they were not familiar with.

They were concerned food products would become ‘contaminated’ or ‘altered’ after the active component was released in the packaging atmosphere. Many consumers view “fresh foods” as those recently produced or those that are not highly processed.

The benefits of active packaging are not always aligned in consumer minds. So, for example, extending the shelf-life of a product and keeping its freshness seem to be a contradiction in consumers’ minds,” she said. 

Freshness is a rather vague promised benefit and people have different interpretations of it.

They may perceive it in terms of time passed from production, where a shorter time equates a fresher food product. This means consumers do not see a product with an extended shelf life as being necessarily fresh, since a longer time has passed since production.” 

Chrysochou added the success of food packaging technology depends on its characteristics and its benefits and how consumers understand them.

In relation to the characteristics of the technology, nanotechnology was not perceived negatively from our respondents, while it was mainly other elements (e.g. the essential oils) that participants emphasized, especially in a negative tone (since they connect them with other non-food applications),” she said.

In terms of benefits, there is a trade-off between extending a product shelf-life (and what interests food producers) and freshness (what interests the consumers).

Such a trade-off is very important to understand since a possible benefit from this, a food packaging technology (i.e. extending shelf-life) may not result in acceptance if freshness is compromised in the consumers’ minds.”

Three-year project

NanoPack is a three-year EU project to develop active packaging for perishable foods. So far, research has included; trials on fresh cherries and wheat-based bread loaves to extend their shelf-life using NanoPack films in partnership with Ctic Cita technology centre, in Spain. 

Trials have shown NanoPack films can extend their shelf life by two days which corresponds to a 40% increase in saleablilty. It plans to test bread next looking at the amount of mold growth on the surface of bread baked working with Pão de Gimonde Portuguese SME bakery.Loaves of bread packed in NanoPack film showed a shelf life increase of up to seven days.

The next trials will take place on dairy products including soft and hard cheeses and yogurt.

Other highlights include the first pilot scale production of NanoPack packaging films at Constantia Flexibles on its CFlex line in Vienna, Austria. Two NanoPack packaging films have been produced on the line, a multilayer polyethylene cast film and an extrusion coated aluminum foil. 

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Polymer resins containing halloysite nanotubes (HNTs) loaded with a mixture of essential oils were used in both film production techniques.

HNTs are considered to be one of the most promising natural nanomaterials because its properties include a tubular structure, high aspect ratio, low cost and abundant availability, good biocompatibility and high mechanical strength.

Their potential to serve as nanoscale containers for encapuslation of antimicrobial molecules has so far only been investigated on a laboratory scale so NanoPack intends to explore its suitability for mass-scale industrial food packaging applications.

To do this, the surface of the HNTs are chemically modified to allow efficient loading and controlled release of natural essential oils (natural substances derived from plants that are generally recognized as safe and show antimicrobial activity against a microorganisms, including bacteria, yeast and mold).

NanoPack will develop large-scale processes and methods for loading HNTs with different essential oils and incorporating the loaded HNTs into polymers for use in food packaging films.

The project will also demonstrate that loading antimicrobial essential oils into HNTs will increase their thermal stability, and allow them to be incorporated into high-commodity polymer packaging films using existing processing techniques.

Essential oils as a vapor

Unlike common antimicrobial agents that function only in direct contact with packaged food, essential oils are released as vapor from the packaging materials into its headspace, and are capable of sanitizing both the product surface and the headspace.

NanoPack held an annual meeting, hosted by IVV Fraunhofer in Freising, Germany, on February 19–21, attended by members of NanoPack’s Advisory Board including professor Lilia Ahrné from the University of Cophenhagen and Professor Diána Bánáti, executive and scientific director at the International Life Sciences Institute (ILSI) Europe.

Chrysochou said the meeting was dedicated mainly to the development aspects, and focuses primarily on operational issues to drive the project towards its last stage.

The take-away message was we need to understand how these benefits interact and find ways to communicate the benefits of the technology that will increase consumer acceptance,” she said.

Benefits of NanoPack films include; prolonging the shelf-life of food by up to 25%, pushing Europe as a global leader in food nanotechnology and smart antimicrobial packaging and increasing competitiveness and growth of the industry; reduce operational costs for food manufacturers, packers, shippers and retailers; encouraging technology transfer through the industrial and scientific community to build an educated workforce and enable manufacturers across the supply chain (including SMEs) to take advantage of the technology developed during the project.

One other concern highlighted in the teams’ research was that retailers’ want to be assured any new technology meets product safety criteria. Only after this has been resolved, can it be aligned with the strategy and internal processes of the company. 

“Regulatory compliance is an important factor to consider: any new technology that is to be brought to the market must comply with specific regulations in accordance with EU legislation on food contact materials,” said Dr. Nina Mc Grath, senior manager, food and health science, EUFIC (European Food Information Council).

“In the context of NanoPack, a full health (including occupational) and environmental safety assessment of NanoPack products and processes is prioritized with the goal of ensuring that NanoPack products meet EU and global quality and safety standards.”

The NanoPack Stakeholder Forum now has a LinkedIn group, where representatives of opinion leaders, regulators, food producer associations, food industry, retailers and consumer organisations are invited to engage in discussions about active packaging, nanotechnology, consumer perceptions and the developments taking place within the NanoPack project.

For more information or requests to join click here or contact Rallou Salakou (r.salakou@effost.org).