Changes in the way foods are produced, distributed, stored and retailed, reflecting the continuing increase in consumer demands for improved quality and extended shelf-life for packaged foods, are placing ever-greater demands on the performance of food packaging. Consumers want to be assured that the packaging is fulfilling its function of protecting the integrity, quality, freshness and safety of foods. To provide this assurance and help improve the performance of the packaging, innovative active and intelligent packaging concepts are being developed and applied in various countries. In Europe, however, the development and application of active and intelligent packaging systems have been limited thus far. The main reasons are legislative restrictions and a lack of knowledge about consumer acceptance, the efficacy of such systems, and the economic and environmental impact they may have. Therefore, in 1999, a European study was started within the framework of the EU FAIR R&D programme. It aims to initiate amendments to European legislation for food-contact materials to establish and implement active and intelligent systems within the current relevant regulations for packaged food in Europe. This paper presents an overview of existing active and intelligent systems and their current and future food-related applications. In addition, developments and trends in active and intelligent food packaging are discussed. The objectives and the work programme of the European project are reviewed and the results obtained so far are presented. The benefits for both the European consumer and the European food and food-packaging industries are highlighted.

Impact-modified and unmodified L-polylactide and L-polylactide-polycaprolactone co-polymer films were evaluated for their suitability as materials for cheese packaging. The polymers were in some cases compounded with nanoclays as a possible route to enhanced barrier properties and/or with cyclodextrin complexes designed to provide slow release of encapsulated antimicrobials for control of mould growth on packaged cheeses. The materials demonstrated complete biodegradation under controlled composting conditions and the extruded films had acceptable transparency. Moisture uptake by films and a decrease in polymer molecular weight with time of exposure to high humidity were identified as areas of concern, although the polymer stability experiments were undertaken at 25°C and stability at normal cheese storage temperatures (~4°C) is expected to be better. Nanoclay addition enhanced the thermal stability of the polymer but reduction of oxygen and water vapour permeability to target levels through incorporation of 5% w/w nanoclay was not achieved, possibly in part due to inadequate dispersion of the nanoclays in the chosen polymer matrices. On the positive side, a novel impact-modified polylactide was developed that overcame problems with brittleness in unmodified L-polylactide and L-polylactide-polycaprolactone copolymer films, and tests indicated that a cyclodextrin-encapsulated antimicrobial (allyl isothiocyanate) incorporated in L-polylactide-polycaprolactone co-polymer films would be effective in controlling fungi on packaged cheeses. Migration of substances from the L-polylactide or L-polylactide-polycaprolactone films into cheese is not expected to be a problem.

The prevalence of allergic contact dermatitis (ACD) caused by nickel is increasing. The probable cause is the increased use of nickel-containing metals in intimate contact with the skin. The critical factor is the amount of nickel released from these metals (bioavailable nickel) onto the skin. In the present study, we determined, with flame atomic absorbtion spectrometry, the amount of nickel released into synthetic sweat from metal samples. The results of this method were compared with the results of the dimethylglyoxime (DMG) test, which is considered to be a reliable means of identifying whether nickel-containing metals may cause allergy symptoms in sensitive individuals. Out of 10 samples studied, only small amounts (< 0.5 microgram/cm2/week) were released from 2 samples, and the DMG test was negative. From 5 samples, more than 0.5 microgram/cm2/week was released, and the DMG test was positive. For 3 samples, however, the DMG test was negative, though the flame atomic absorption spectrometry test showed considerable release of nickel. Therefore, although the DMG test can be used as a first line test for determining nickel release, some DMG-negative metal materials probably induce nickel sensitization, and should by no means be advertised as safe in this respect. We also report a nickel-allergic patient who developed ACD from stainless steel, indicating that some types of stainless steel release enough nickel to elicit allergic symptoms.

In order to study the purity of recycled fibre-based materials, products containing recycled fibre as well as recycled pulp were examined with regard to their chemical impurities, toxicity and microbiological quality. The study was carried out to clarify both qualitatively and quantitatively the variations in microbiological quality. The levels of several classes of chemical substances were analysed and semi-volatile and volatile substances identified. The toxicity and mutagenicity of virgin fibre and recycled fibre materials were screened using the Photobacter toxicity test and the Ames Salmonella mutagenicity test. Preliminary chemical characterization of the mutagens was carried out. Identification of the compounds found in the mutagenic fractions was performed by gas chromatography/mass spectrometry (GC/MS). The concentration of various substances analysed was found to be low, although the variety of substances present appeared to be very broad. Preliminary chemical characterization revealed that some samples contained compounds known to have mutagenic or other toxic activity. Also, the recycled fibre pulps contained large amounts of various microbes, the microbial load consisting mainly of aerobic spore-forming bacteria. The paper-making process was found to clearly have reduced the total microbial counts.