REDI answers questions

Q    Can you give more information about the chitin?

A     Chitin is the most abundant biopolymer after cellulose in nature. In its pure form, chitin is translucent, pliable, resilient, and quite tough and has the ability to form materials such as fibers, hydrogels, beads, sponges, and membranes. Chemically speaking, chitin is a biopolymer. A polymer has the structure of a chain of repeated elements like a pearl necklace. In the case of the chitin, the repeated element is a compound called N-acetylglucosamine. Several single polymer strands bind together to form a fiber (Abidin et al. 2020, Int. J. Mol. Sci.; doi:10.3390/ijms21144978).

Chitin Chemical structure

Q    What is chitosan and what is the difference with chitin?

A     Chitosan is known as the “deacetylated” form of the chitin. In few words, the chitin molecule is modified to increase water solubility. This process is highly appreciated in the biomedical industry and specifically for tissue engineering applications as chitosan shows outstanding antimicrobial properties as well as excellent biodegradability and biocompatibility (Sultankulov et al. 2019, Biomolecules; doi:10.3390/biom9090470).

Q    Is Bioplastic safe for the environment?

A     Plastic is composed of long-chain molecules named polymers. Bioplastic is composed of polymers derived from biological sources that, for this reason, are called “biopolymers”. Bioplastic is not always environmentally friendly. Although one may expect from the name that they are safer than synthetic plastics, many polymers derived from living organisms are identical to synthetic ones from the chemical point of view. Since the term “bioplastic” is misleading, it is indeed preferred to identify environmentally safe products as “compostable”. Among compostable polymers, chitin is the second most abundant biopolymer in nature and is a structural component of the insects’ body.

Q    What are the advantages of chitin based bioplastic?

A     Chitin can be used to produce single-use items as well as durable objects with the unique advantage to be recyclable, compostable, and antibacterial properties. Plastic obtained from chitin is comparable to PET (polyethylene terephthalate), one of the most common petroleum-based materials used as transparent packaging. Nevertheless, chitin-based materials showed up to 67% reduction in oxygen permeability over some forms of PET, meaning, for example, they are able to keep food fresher longer. Chitin can also be incorporated into PLA (polylactic acid) to form composite materials with enhanced thermal and mechanical properties.

Q    You plan to produce chitin bioplastic from insects growing in organic waste. Is it safe for the human health?

A     Chitin bioplastic is totally safe. All living organisms reprocess elements present in the environment to produce energy, new compounds, and waste. This process comprises a complex sequence of chemical reactions that are called metabolism. Animals, in particular, break down nutrients assumed with the food to produce energy and simple molecules that are used to build up new structures (biomass). The Black Soldier Fly feed in the organic waste, reprocessing the nutrients into new materials, included chitin. Therefore, this new plastic is not made of garbage. The entire process is similar to the production of milk from cows: we cannot say that milk is composed of grass, we can only say that milk is produced by cows that feed with grass. In addition, due to its chemical structure, chitin bioplastic has antibacterial properties.

Q    We see images and videos of rafts of plastic objects floating on the surface of the ocean. Is it a problem with the plastic itself or it depends on human behaviour?

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A     The utility of plastic is undoubtful: it is cheap and can be used to produce a huge variety of commodities. Unfortunately, it takes around 400 years to degrade in normal environmental conditions. Also, there are several other issues linked to traditional plastic, from the use and abuse of the resources, to the carbon footprint of the production systems, to the insufficient disposal and recycling processes. In addition, there are also important economic factors shaping the market of plastic. The general picture is therefore very complex, however, it is true that an increase of individual responsibility is absolutely needed. Unfortunately, it is totally insufficient! There are many types of plastic, some can be recycled but others cannot (mainly for economic reasons). Therefore, even in the best utopistic scenario in which no one leaves plastic materials on the beach or in natural places and in which all the plastic is correctly disposed of, we will have an accumulation of plastic in landfills and we would need to allocate huge areas just to stock the plastic waste with huge economic losses. We will not see any more plastic in the oceans, but we will be drowning in plastic anyway. It is like sweeping the dust under the carpet!

Q    So, what is the solution?

A     We think that, on one side, the recycling process should be massively increased but, on the other side, is also vital to promote the adoption of new sustainable materials that, ideally, are not only sustainable but can enter as a component in the ecosystems and can be reprocessed by the existing ecological food chains. This is what “The REDI project” is aiming to do.