scale. Therefore, several films were selected to pack food products on
industrial packaging lines.
For French fries, the Natureflex™N913 and N931 films were
selected. The Natureflex™N913 film ran smoothly on the machine
(vertical flow pack) and a good sealed pouch could be made (longitudinal
seal at 180 °C, vertical seal at 130–160 °C). The Natureflex™N931
film did not run very smoothly on the machine and the longitudinal
seal could not be made. Both films also appeared too brittle to fill with
5 kg of French fries.
For ham sausage, the Natureflex™N913 and N931 films were
selected. The films ran smoothly over the machine (horizontal flow
pack), but sticked to the sealing bar when the vertical seal was made.
This problem could be overcome by the use of Teflon on the sealing
bar. Good sealed pouches could be made (longitudinal seal: 180 °C–
vertical seal: 140 °C). Ham sausage was MAP-packed and the gas
composition in the headspace was followed up. A lot of variation in
gas concentration in the headspace was found, but the limit of 1.5% O2
was not exceeded for Natureflex™N913 pouches with a good initial O2
concentration.
For Strasbourg, two new films, the Natureflex™N948 and the
Cellulose™NK/PLA films were selected. Both films ran smoothly on the
machine (horizontal flow pack), but sticked slightly to the seal bar.
Good sealed packages could bemade (longitudinal seal: 115 °C–vertical
seal: 130 °C). Strasbourg was MAP-packed (30% CO2/70% N2) and the
gas composition in the head space was followed up during 12 day
storage at 4 °C. As can be seen in Table 4, the O2 concentration in the
headspace remained lowand stable in all packages during the shelf-life.
4. Conclusions
Bioplastics have potential for packaging applications in the food
industry. It is demonstrated that biobased multilayer structures can
guarantee the quality of several short and medium shelf-life food
products including products packed under MAP. The gas and waterbarrier
properties of the investigated biobased packaging materials are
sufficient to achieve the same shelf-life as in the case of conventional
packaging, even though they did not always posses the same (strict)
high gas-barrier. This also gives new research opportunities for investigating
combinations of different newly developed biobasedmaterials in
order to obtain biobased packaging materials with appropriate gas and
water-barrier properties. It is also demonstrated that different UV–VIS
transparency properties of the biobased material can cause more
discoloration of sensitive food products. Furthermore, packaging trials
at companies showed a good compatibility with industrial filling
machines.When testing biobased packagingmaterials, sufficient testing
time should be foreseen in order to find the optimal combination of seal
time, seal temperature and seal pressure. Brittleness of some biobased
films could also negatively influence vertical filling processes. It should
also be mentioned that besides this technological performance, the
current price as well as the waste management options of biobased
materials are important parameters in the decision and implementation
process of companies whether or not to add bioplastics in their product
portfolio.
Acknowledgments