A Brief Overview of Food Packaging R&D in Portugal

Maria de Fatima Poças

The food packaging industry in Portugal is represented by all sectors: glass, metals, plastics, paper and board, printing and other converting operations, and cork. Some of the major companies originated as Portuguese, family-owned businesses that have grown in size and scope of activity to become major, international operations often with sites in different countries. In others cases, local companies have been integrated into large multinationals. This globalisation of the business is reflected in many other aspects of the industry in Portugal, such as raw materials, technology employed and on research and development. The research performed is most often focussed on challenges which are very close to the application of existing technologies or knowledge and as such is essentially incremental.

A notable exception in this respect is the cork industry, more specifically the cork closures industry. The Portuguese cork-closures industry is highly vertically integrated with the world’s largest cork-oak forests and the majority of its cork transforming capacity. A traditional industry, it is very much dependent on another traditional sector – wine – and was compelled to initiate important R&D efforts mostly driven by the increasing penetration on the international market of new closure systems for wine packaging such as screw caps. This is not to underplay the R&D which is performed in Portugal following the international trends on novel packaging materials and applications, such as active systems, nano-based materials and materials developed from natural sources.

The objective of this paper is to present an overview of recent and ongoing R&D efforts within the food packaging industry players in Portugal.

Cork Closures Performance

Research and development efforts in cork closures have often focused on the mitigation of off-flavours transmitted by cork to wine. The INNOCORK project gave rise to a new patented process with improvements to avoid these contaminants. The volatile organic compounds responsible for sensory problems in corks are removed from the cell structure of corkwood by a process involving physical-chemical actions of temperature and solvent polarity of a carrier gas composed of water vapour and ethyl alcohol. The efficiency of the process removes contaminants down to acceptable levels of less than 3 ng/L (Anon. 2007, Neto et al. 2007). Other strategies to tackle this taint problem include ROSA, SYMBIOS and DELFIM processes.

New types of cork closures, employing improved coatings and agglomerating agents, is the subject of a number of research initiatives promoted by consortia bringing together industry and R&D institutions. The CorkToBe project aimed at the development of a polymeric coating with improved barrier properties. This coating layer avoids the migration of coloured phenolic compounds allowing the cork closure to be used in white spirits without the unwanted taint of the beverage by the extraction of cork components. The system has a European patent pending (Oliveira et al. 2008).

Safety and Performance Evaluation of Packaging

On safety of packaging materials in contact with foods and the chemical hazards they may represent, the use of mathematical tools to describe migration of packaging components into foods is seen of great interest. The MIGRAMODEL project studied the use of alternative probabilistic models to simulate the migration of contaminants such as phthalates, not only from plastics but also from paper and paperboard. Furthermore, the simulation models are integrated into a general procedure to assess the exposure of consumer to these potential hazards Poças et al. 2010).

In the closures sector new methods to assess the oxygen transmission rate (OTR) in bottles have been developed with relevance for the wine sector. One is a non- destructive colorimetric method to be used after filling the bottle and applied to metal screw caps, corks and plastic stoppers (Lopes et al. 2005). The other is applicable to plastic cellular closures and is intended to reduce the measuring time of the standard method to determine the OTR (Poças et al. 2009).

Environment Impact and Production Sustainability

These issues are horizontal to all packaging sectors, including the pulp and paper. In this sector, efforts have been made upstream, often targeting energy savings and sustainable forest management practices. Alternative Cardoon fibre to Eucalyptus for paper and paperboard production was studied with promising results for liner manufacture and as reinforcement of recycled fibres (Abrantes et al. 2007).

In the plastics industry, the use of inert gases such as carbon dioxide and nitrogen as an alternative to hydrocarbons as blowing agents to produce polyethylene foams has been subject to significant research in industrial processes. Claimed advantages in terms of environmental impact and material safety are made for both inert gases. Synthetic closures, when produced by extrusion, are particularly receptive to the use of carbon dioxide as the blowing agent because of the relatively high density of the foams for this application (Ferreira, pers. commun).

New Materials Based on Natural Sources

Attempts to produce materials and coatings from natural ingredients and food industry waste streams are popular among academic researchers. The examples mentioned are related to traditional Portuguese products. Under the scope of MILKFILM and CHEESECOVER projects, edible films and coatings were developed from milk whey protein isolate recovered from the waste stream of cheese production. The materials have application for packaging as self-supported films and as food coatings. The materials such as chito-oligosaccharide were proved to be a suitable support for anti-microbial agents. Compared with traditional polyvinyl acetate coatings, the films allowed for a 10x reduction in the concentration of chemical preservatives with better performance in terms of protection against microbial growth (Ramos et al. 2010). The preparation of polyols from renewable resources, in this case olive stones, by an oxypropylation process is under study in the OLIVPOL project. The polyols obtained are suitable for polyurethane foam formulations (Alvarado et al. 2005).

Novel Materials Based in Nanotechnology

The application of nanotechnology to packaging systems to enhance performance is expected to improve the safety and quality of foods. The NANOPACKSAFER project is an Iberian joint research effort which includes the integrated development of edible and non-edible nano-materials and respective production systems. The project is just starting and therefore no results are available yet. Evaluation of safety and bioavailability will be considered as well as methods to detect and characterise the films and nano-components.

References

Anon. (2007) Uma nova tecnologia desenvolvida para a redução de voláteis em rolhas de cortiça natural: o processo INNOCORK. [New technology for volatiles reduction in natural corks: INNOCORK process] http://www.apcor.pt/. [accessed 17.11.09]

Neto, PV, Rocha, S and Silvestre, A (2007) Simultaneous headspace solid phase microextraction analysis of off-flavour compounds from Quercus suber L. cork. J.Sci. Food Agric. 87: 632-640.

Oliveira, F, Pontes, S, Cabral, M and Mendes, A (2008) Development of a coating barrier for cork stoppers for their use in spirituous drinks. Oral presentation, IJUP08, First Meeting of Young Researchers of U. Porto, Porto, Portugal, 20-22 February 2008.

Poças, MFF, Oliveira, JC, Pereira, J and Hogg, T (2010) Consumer exposure to phthalates from paper packaging – an integrated approach. Food Add. Contam. (submitted).

Lopes P, Saucier C and Glories, Y (2005) Nondestructive colorimetric method to determine the oxygen diffusion rate through closures used in wine making. J. Agric. Food Chem. 53: 6967-6973.

Poças, MF, Ferreira, B, Pereira, J and Hogg, T (2009) Measurement of oxygen transmission rate through foamed materials for bottle closures. Packag. Technol. Sci. Published Online: Oct 14 2009, 6:44am.

Abrantes, S, Amaral, ME, Costa, AP and Duarte, AP (2007) Cynara cardunculus L. alkaline pulps: Alternative fibres for paper and paperboard production. Bioresource Technol. 98: 2873–2878.

Ferreira, B. Personal communication. Epoli-Espumas de Etileno, S.A. (Trofa)

Ramos, O, Fernandes, JC, Silva, S, Pintado, M and Malcata, FX (2010) Edible films and coatings from whey proteins: A review on formulation and on mechanical and bioactive properties. Crit. Rev. Food Sci. Nutr. (submitted).

Alvarado, P, Sibaja, M, Jimenes, L, Barreiro, MF, Cateto, CA, Rodrigues, AE and Lopretti, M (2005) Bio-based composite materials from olive stone. Proceedings of 14th European Biomass Conference and Exhibition. 17- 21 October 2005, Paris, ETA - Renewable Energies.

Dr Maria de Fatima Poças is Head of the Food Packaging Department, Biotechnology College, Portuguese Catholic University, Porto, Portugal; E-mail: mfpocas@esb.ucp.pt