Biodegradable Antibacterial Film for Storing Food

At RUDN University, a group of chemists developed such a coating from polysaccharides—natural macromolecules that act as the building blocks of living organisms. Polysaccharides are non-toxic and biodegradable and do not have a negative impact on health

The antibacterial coatings recommended by the researchers are based on a polysaccharide called chitosan that is present in lower fungi or in carapaces of crabs. The chemists particularly used two derivatives of chitosan: chitosan succinyl sodium salt (SC-Na) and a compound of triazole, betaine, and chitosan (TBC)

The latter has antibacterial properties similar to those of present-day antibiotics. According to the researchers, TBC nanoparticles entrench into a matrix or SC-Na grid, producing a thin even film

It is relatively powerful when compared to any of its individual components and allows only minimal steam and oxygen in. During the course of the experiments, the researchers verified that the film is the most efficient when the SC-Na to TBC ratio is 1 to 1

Kritchenkov added, “We based our coating on SC-Na, a salt with high film-forming ability. Moreover, it is not toxic and works as an antioxidant, increasing the shelf life of food products. By changing the TBC/SC-Na ratio, we developed multifunctional food coatings with improved antibacterial, protective, and mechanical properties.”

To validate their invention, the researchers placed a number of bananas in the film for a period of 10 days. During the course of the experiment, the researchers quantified the vitamin C content, weight, and the concentration of carbon dioxide emission in the fruit

Following 10 days, these parameters were compared to the outcomes from the control group that was kept without coating. It was observed that the coated fruit lost eight times less vitamin C and three times less weight and that the frequency of its “breathing” was 2.6 times lower (that is, metabolic processes related to reduced CO₂ emissions)

Due to these properties, chitosan-based films can be utilized for storing food products. Once a film has been utilized, it will decay without causing damage to the surrounding

 SEP 28 2020

Ref: www.azom.com