An edible anti-microbial coating incorporating cannabidiol (CBD) and sodium alginate could extend the shelf life of fruit, World Bio Market Insights reported researchers as writing on the American Chemical Society (ACS)’s Applied Materials & Interfaces website.

Popular due to its potential therapeutic effects, CBD had also been shown to have antioxidant and antimicrobial properties, the report said.

In previous studies, CBD had limited the growth of some bacteria and pathogenic fungi, such as the ones that caused fresh fruit and vegetables to rot, World Bio Markets Insights wrote.

However, the oily compound needed to be evenly distributed in water before it could be widely incorporated into foods or used for food preservation, the report said.

As one way to achieve this would be to encapsulate the CBD molecules in edible polymers, researchers Pongpat Sukhavattanakul, Sarute Ummartyotin and their colleagues wanted to see if a food coating made using CBD-filled nanoparticles could promote antimicrobial activity and extend the shelf life of strawberries.

As part of the project, the research team encapsulated CBD in poly(D,L-lactide-co-glycolide), a biodegradable polymer used in drug delivery, producing 400-nm-wide particles. The most stable nanoparticles, containing 20% by weight CBD, were mixed with sodium alginate in water.

The strawberries were then submerged into solutions containing different amounts of nanoparticles before a second dip in a mixture of ascorbic acid and calcium chloride to turn the colourless coating into a gel.

Untreated and treated strawberries were then placed in open plastic containers at refrigerator temperatures.

After 15 days, CBD-treated samples ripened and decayed much more slowly than untreated ones, possibly due to reduced microbial growth, the report said.

The coating with the most CBD-loaded nanoparticles preserved the berries’ dark red appearance, enhanced their antioxidant activity and achieved the highest antimicrobial protection over the storage period, suggesting that this version would give the longest shelf life.

According to the research team, the results of the study demonstrated how encapsulated CBD could be used to create a colourless antimicrobial coating for active food packaging.