Bioplastics
in Food Packaging
Plastics are a huge part of food packages. They are widely
used because of their easily shaped nature, low cost, and other functional
advantages like optical properties, thermo sealability, microwavability. The
use of petroleum-sourced materials in plastics production can pose a danger to
the ecosystem due to their increased carbon release to the atmosphere, their
long-term non-degradation in nature, and their carcinogenic effects [1]. So, is
a world without plastic possible? It is quite possible with the use of
bioplastics.
Bioplastics are plastic materials that are either biobased,
biodegradable, or feature both properties, and Figure 1. depicts their
classification in terms of biobased and/or biodegradable bioplastics [1,2].
Figure 1. The coordinate system of bioplastics’ classification [2].
Biobased and biodegradability are entirely
different features. Biobased refers
to the materials or products derived from biomass, such as corn, sugarcane, or
cellulose. On the other hand, biodegradable
materials undergo a chemical process during which no artificial additives are
needed. Microorganisms in the environment convert these materials into natural
substances such as water, carbon dioxide, and compost. This process is highly
dependent on the environmental conditions and the chemical composition of the
material.
Polylactic acid (PLA), polyhydroxyalkanoate
(PHA), and polyethylene furanoate (PEF) are some of the bioplastics that
deserve more attention.
●
Polylactic Acid (PLA): PLAs are synthetic aliphatic
polyesters. They are produced by renewable resources like corn cob, sugarcane
bagasse, potato starch, barley, pretreated wood, or rice hulls by bacterial
fermentation. PLA is synthesized by polycondensation or ring-opening
polymerization reactions. PLA is a great food packaging material because of its
high molecular weight, water solubility resistance, good processability, easy
to process by thermoforming, and biodegradability. Processed PLA products can
be found in various forms, such as films, containers, and coatings for paper
and paper boards. It can be further recycled by chemical conversion back to
lactic acid and then re-polymerized. However, if PLA-based products aren’t
processed under appropriate conditions, it exhibits some limitations for biodegradation.
It becomes brittle and can biodegrade much easily at higher temperature
conditions.[3,4].
●
Polyhydroxyalkanoates
(PHA): PHAs are a class of bacterial polyesters produced with bacterial
fermentation of sugar and lipid components. The monomers that compose different
PHAs depend on the bacterial species that took part in the fermentation
process. They exhibit thermo-mechanical properties akin to synthetic polymers
like polypropylene, making it an ideal material to use. They have excellent
tensile strength, flavor and odor barrier properties, heat sealability, grease
and oil resistance, temperature stability, and are easy to dye, which boosts
their application in the food industry. PHAs are used to produce biodegradable
packages like bottles, containers, sheets, films, laminates, fibers, and
coatings [5,6].
●
Polyethylene Furanoate
(PEF): PEFs are 100% biobased polyesters produced by the fermentation
of corn or wheat-based sugars, wood, corn stover, or bagasse waste. It is
polymerized by using 2,5-furan dicarboxylic acid and monoethylene glycol. PEFs
possess comparable properties of thermal resistance to that of the PETs (polyethylene
terephthalate). Furthermore, they provide twice the amount of water vapor
barrier properties that make it an excellent packaging material. The EFSA panel
announced that “the substance furan-2,5-dicarboxylic acid does not raise a
safety concern for the consumer when used as a monomer in the production of
polyethylene furanoate (PEF) polymer and the migration of the substance itself
does not exceed 5 mg/kg food.” [7].
With the increased use of bioplastics, the
greenhouse gas emissions that are the most important factor of climate change
can be reduced drastically. Also, the recyclability and biodegradability of
bioplastics create a more sustainable economy that can decrease the amount of
plastic waste [8].
.
.
REFERENCES
- Reichert,
C. L., Bugnicourt, E., Coltelli, M. B., Cinelli, P., Lazzeri, A., Canesi,
I., Braca, F., Martínez, B. M., Alonso, R., Agostinis, L., Verstichel,
S., Six, L., De Mets, S., Gómez, E. C., Ißbrücker, C., Geerinck, R.,
Nettleton, D. F., Campos, I., Sauter, E., Pieczyk, P., & Schmid, M.
(2020). Bio-Based Packaging: Materials, Modifications, Industrial
Applications and Sustainability. Polymers,
12, 1-35.
- European
Bioplastics. (2018). What are bioplastics? Retrieved from
https://www.european-bioplastics.org/bioplastics/
- Malathy, A.N.,
Santhosh, K.S., Nidoni, U. (2014). Recent trends of biodegradable polymer:
biodegradable films for food packaging and application of nanotechnology
in biodegradable food packaging. Current Trends in Technology and Sciences, 3, 73–79.
- Cabedo, L, Feijoo, J.L.,
Villanueva, M., Lagaron, J.M., Gimenez, E. (2006). Optimization of
Biodegradable nanocomposites based on a PLA/PCL blends for food packaging
applications. Macromolecular
Symposia, 233, 191–197.
- Mangaraj, S., Yadav, A., Bal,
L.M.,Dash, S. K., & Mahanti, N.K. (2017). Application of Biodegradable
Polymers in Food Packaging Industry: A Comprehensive Review. Journal of Packaging Technology and
Research, 3, 77-96.
- Leja, K., Lewandowicz, G.
(2010). Polymer biodegradation and biodegradable polymers—a review. Polish Journal of Environmental
Studies, 19(2), 255–266.
- European Food Safety Authority
(EFSA). (2014). Scientific Opinion on the safety assessment of the
substance, furan-2,5-dicarboxylic acid, CAS No 3238-40-2, for use in food
contact materials. EFSA Journal, 12(10),
1-9.
- European
Bioplastics. (n.d.). Environmental benefits of bioplastics. Retrieved from
https://www.european-bioplastics.org/bioplastics/environment/