Index
Emerging active packaging solution for food preservation
In recent years, the major driving forces for innovation in food packaging technology have been the increase in consumer demand for minimally processed foods, the change in retail and distribution practices associated to globalization, new logistics, new distribution trends (such as Internet shopping), automatic handling systems at distribution centers, and stricter requirements regarding consumer health and safety.
Active packaging technologies are being developed as a result of these inputs. Active packaging is an innovative concept that can be defined as a mode of packaging in which the package, the product, and the environment interact to prolong shelf-life or enhance safety or sensory properties, while maintaining the quality of the product.
Active packaging is designed to deliberately incorporate components that would release or absorb substances into or from the food or the environment surrounding it. They are of specific relevance to improve the safety and maintain nutritional quality over the time in minimally processed foods or even organic products where it is difficult to introduce additives.
They rely on the strategy to protect the area of the food that is most exposed to external contamination or spoilage and may therefore limit the overall quantity of used additives. In addition, a number of active substances can be extracted from bio-based feedstocks, as well as from by-products from food processing to maximise the new packaging concept circularity.
IRIS Technology Solutions is strongly committed to supporting the factories and their value chain in the circular and bio-economy transitions. As such, IRIS innovation lines spread from bio-based and/or renewably sourced products for reduced carbon footprint to the development of new applications of bio-based compounds with unique environmental, functional and/or safety performance applying digitisation towards Circular4.0 and Bio4.0.
In that context, IRIS is currently participating in 4 cutting edge projects ECOAT, DAFIA, REFUCOAT and AGRIMAX, further exploiting the promising results and the extensive know-how gained over the years in several R&D projects as OliPHA. The topics of these projects spread from the valorization of by-products to produce bio-based coatings to the use of bio-actives for improving the functionalities of packaging
ECOAT
The project aim is to develop antimicrobial-antioxidant coatings based on chitin nanofibrills, chitosan and functionalized microbial cellulose for cellulose tissues, paper and cardboard, woven and nonwoven (sanitary) and plastic substrates for active packaging providing improved performances compared to currently available products and at the same time with more sustainable end of life options.
To achieve this goal following a circular approach, ECOAT will select, extract and functionalise molecules (proteins, polysaccharides, cutin) with specific performances (water repellent and water vapour barrier (cutin), oxygen barrier and adhesiveness) from highly available, low valorised biomass such as tomato, legumes, sunflower (Figure 1).
The final prototypes will include cutin based formulations for coatings water repellent products (paper cups, service paper etc.), water vapour barrier (packaging) and protective properties (non-food packaging) and protein- based barrier adhesive for multilayer food packaging (bio polyesters based), with sustainable end of life options (composting, recyclability).
In order to guarantee constant active properties while not using more resources than required, the consistent application of the active coating is of crucial importance. Indeed, to achieve the proper functionalities, several microns thickness coatings are usually applied to reach the multifunctional requirements of the specific applications. As such, a proper monitoring both along and across the samples is fundamental for quality and economic reasons.
Thanks to our extensive experience in photonic-based techniques, IRIS will contribute to this objective of the project, providing an in-line optical tool that will permit the development of the final formulation and the optimization of the process reducing scraps and waste. Hyperspectral imaging (HSI) has already been demonstrated as a suitable technique to in-line monitor the distribution of coating on the substrate (Figure 2).
REFUCOAT
Antioxidant and/or antimicrobial are among the most studied active packaging and are targeted in REFUCOAT depending on the respective needs of the different food products considered in the project. The application of active substances is especially of interest in biopolymer-based packaging as they often fail to provide equivalent protection to food versus their synthetic counterparts and can even be sensitive to microbiological spoilage themselves.
Active packaging further contribute to the over-ridding goal of the REFUCOAT project to provide gas barrier layer based on renewable resources that can substitute EVOH (ethyl vinyl alcohol copolymers) or metallisation (AlOx) most commonly used as barrier materials in modified atmosphere packaging but jeopardizing the later recyclability of the resulting laminates.
In this context, hybrid coating prepared from bio-based Poly Glycolic Acid and silanes precursors are being developed to provide high passive barrier to both oxygen and water vapour permeation. It will now be combined with the active coating to ensure an optimal food protective effect by the hybrid coating and shelf-life extension by the active substances.
Different antioxidants meeting food safety requirements were tested to pack the selected savoury food products (potato chips and bread crumps): Ascorbic Acid (E-300), Tocopherol Extract (E-306) and α-Tocopherol (E-307). Formulations using biobased binders such as alginate suitable for application by wet coating on different plastic substrates were developed.
The shelf-life (via physico-chemical, microbiological and organoleptic studies) of potato chips and bread crumps packed in pouches made from coated PLA and bio-PE layers among others is being studied in accelerated storage conditions to verify if the bio-based active materials can compete with their fossil counterparts and even extend the food shelf-life.
Such coated materials recyclability will also be studied respectively via composting and reprocessing trials. When applied on biodegradable substrates, the former is not expected to be affected by the active coating made of biodegradable compounds whereas the later may be possible when limiting the coating thickness.
DAFIA
For example, in the project DAFIA, marine rest raw-materials such as salmon skin and backbones are harnessed to develop cost-efficient isolated and purified gelatin and hydrolysates. Gelatin is a denatured polypeptide extracted by hydrolysis from pre-treated collagen sources, mainly animal skins and bones, which is mostly affected by its amino acid composition and molecular weight distribution.
The fractionation and lipids separation pre-treatment protocols have been optimized in mild conditions. The coating was formulated comparing different natural plasticizers, pH and temperature as well as drying conditions. Furthermore, the mechanically separated salmon muscle has been hydrolysed with proteases as potential antioxidant and antimicrobial actives. The addition of hydrolysates has shown positive antioxidant activity.
The coating application and lamination have been successfully carried out at pilot scale by AIMPLAS resulting in laminates with promising oxygen barrier. This shows that bio-macromolecules from marine sub-products have a great potential to be used as high added value active barrier coatings for multilayer packaging or edible coatings directly applied on food.
OliPHA and AGRIMAX
Olives are rich in polyphenol, which have excellent antioxidant, anti-allergic, anti-inflammatory, anticancer, antihypertensive, and antimicrobial properties. In the spirit of circular economy, they can be extracted from by-products from olive culture and processing such as from olive mill waste water, pips or leaves.
In OliPHA, the polyphenols extracts (80 % hydroxytyrosol) recovered from the former source were either used in cosmetic formulations or applied as coatings on polyhydroxyalkanoate (PHA) biopolymer and on polyethylene (PE) plastic films to develop active packaging solutions taking benefits of the polyphenols inherent antioxidant and antimicrobial properties.
A comprehensive series of tests were carried out in order to validate the effectiveness of the Oli-PHA based packaging for safeguarding the quality and safety of the packed goods, such as microbial assessment, sensory analysis andshelf-life determination. The barrier properties to oxygen, light and humidity were tested. While PHAs present interesting barrier properties even vs. other standard and bio-sourced polyesters to be used as passive packaging, the use of active coating with polyphenols allowed decreasing the oxygen permeability by a factor 4.
In terms of food packaging validation, significant reductions in lipooxidation in minced meat and in microbial growth in Gouda cheese were observed with active packaging solutions. In terms of use in cosmetics, the polyphenolic extract also displayed high antimicrobial activity and potential to be used as alternative to standard preservatives. In particular, the use of the extract as preservative in a cream and in a shampoo allowed reducing the microbial activity vs. standard packaging.
Beyond this, AgriMax project uses another source for olive phenols, such as pomace, a mix of olive peels and bones obtained as a by-product from the oil processing industries. The phenols are extracted using ultrasound technology, as seen in a past issue of the Food Hub magazine, and lyophilized to obtain pure phenols in powder, rich in antioxidant properties. When dissolving the lyophilised compounds in water, the antioxidants power of the extracts is maintained.
This bio-active powder is currently being used for the development of active packaging solutions for the food industry; in one side, introduced in solution for PHA compostable films coating and, in the other side, compounded and blended with PLA (Polylactic acid) and PBAT (Polybutylene adipate terephthalate) for compostable films extrusion. The release rate and the kinetics of the active on the different packaging are being studied, as well as the microbiological and organoleptic properties, through shelf-life analysis, to quantify the impact of the bio-films on the food industry. Within the scope of AGRIMAX project, the active packaging will be tested with fruits that have different spoilage mechanisms, as strawberries (non-climacteric fruit) and tomatoes (climacteric).
Consumers preferences will further accelerate packaging innovation
Although active packaging is still considered a novel food packaging technology, consumer’s demand for ready-to-eat and minimally processed food products with maintained quality will exponentially accelerate development, customers’ acceptance and market uptake of intelligent packaging solutions.
This is compounded by the fact that active packaging main result is to extend product shelf life, which contribute to fight against one of the leading global concerns, by reducing food waste.
Consumers’ sustainability concern and commitment will lead to packaging tendency to evolve to new solutions that combine intelligent technologies allowing both food safety, packaging compostability (avoiding environmental cost) and zero waste production towards a green approach during the entire food value chain.
[1] Vermeiren and others 1999; Sonneveld 2000
[2] ECOAT has received funding from the Bio Based Industries Joint Undertaking (JU) under grant agreement No 837863. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio Based Industries Consortium.
[3] REFUCOAT, H2020 BBI, GA 745791, Full recyclable food package with enhanced gas barrier properties and new functionalities by the use of high performance coatings DAFIA has received funding from the Bio Based Industries Joint Undertaking (JU) The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio Based Industries Consortium.
[4] DAFIA, H2020 BIOTEC, GA 720770, Biomacromolecules from municipal solid bio-waste fractions and fish waste for high added value applications.
[5] OLI-PHA, A novel and efficient method for the production of polyhydroxyalkanoate polymer-based packaging from olive oil waste water, FP7 Grant Agreement no: 280604-2
[6] AGRIMAX has received funding from the Bio Based Industries Joint Undertaking (JU) under grant agreement No 720719. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio Based Industries Consortium.
[7] www.foodhubmagazine.com/2019/08/31/application-of-power-ultrasound-in-the-food-processing-industry/
Simona Neri, Edurne Suárez, Elodie Bugnicourt, Laura Rodríguez, Cristina Fernández and Justine Muller
Are part of the PMO and Science & Engineering department of IRIS Innovation (www.innovationatiris.com) which is part of IRIS Technology Group (www.iristechnologygroup.com). IRIS Innovation performs research and development for generating new knowledge, knowhow, and technological advancements in Applied Photonics, ICT, and Circular-Bio Economy. It has an international and multidisciplinary team with expertise spreading from project & innovation management, Engineering and Science (materials, environmental and food science, chemistry, physics and data science).
