New bioactive plastic made from mango leaves improves food preservation

Plastic wraps are good at keeping food fresh while it’s on supermarket shelves, but lately we’ve seen more advanced and durable forms of these materials that also play a role in preventing spoilage. For example, in May, Fraunhofer-Gesellschaft researchers produced an environmentally friendly bioactive paper liner to replace plastic for food packaging. Another compelling example comes from researchers in Spain and Portugal. They have developed a new “bioactive” material that uses mango leaf extracts to repel ultraviolet light and common foodborne pathogens.

Researchers created the new bioactive plastic from mango leaves at the University of Aveiro in Portugal and the University of Cadiz in Spain, who collected mango leaves from pruning remains at a farm local. The researchers combined mango leaf extract with nanocellulose from paper processing to produce the new film by supercritical solvent impregnation.

This technique has several advantages over conventional plastic manufacturing, in particular it allows the mango extract to penetrate the nanocellulose more efficiently, promoting the migration of the active compounds. The resulting film has better food preservability due to its higher concentration of antimicrobial and antioxidant compounds. “In this way, the active properties of the mango remain intact after impregnation, which increases the ability of the film to protect food”, explains Cristina Cejudo, researcher at the University of Cádiz.

Nanocellulose paste before polymerization

The team tested the film via in vitro experiments against two foodborne pathogens: Escherichia coli and Staphylococcus aureus. The results showed that the active compounds in the film took on an antimicrobial role and prevented the spread of the particular bacteria.

Additionally, mango extracts increase the film’s ability to block UV light, which could otherwise dramatically accelerate food spoilage. “Thanks to him, the foods packaged in this film could be stored longer without the addition of preservatives. The film itself replaces the chemical additive since the active substance exerts its effect through the packaging without the need to add anything to the food,” Cejudo added.

This new bioactive plastic could prevent tons of food waste around the world. The team plans to conduct further experiments by studying its performance in preserving specific foods. The research was published in Food Hydrocolloids.