A strawberry enveloped in an edible CBD coating (left) still appeared fresh compared to an untreated berry (right) after 15 days. Credit: Adapted from ACS Applied Materials & Interfaces 2023, DOI: 10.1021/acsami.3c04036
Key points:
- A team in Thailand developed an edible food coating using CBD-filled nanoparticles.
- After 15 days, CBD-treated strawberries ripened and decayed much more slowly than untreated ones.
- The researchers say that their results demonstrate how encapsulated CBD could be used to create a colorless antimicrobial coating for active food packaging.
Strawberries always have a difficult drive home from the grocery store. Whereas they may look fine in the plastic tubs in the stand, by time you get home, the ones at the bottom (and sometimes even the top) have gotten squishy and rotten.
To increase berries’ shelf life, researchers have incorporated cannabidiol—a non-hallucinogenic compound from cannabis known as CBD—and sodium alginate into an edible antimicrobial coating.
CBD is popular because of its potential therapeutic effects. But this cannabinoid has also been shown to have antioxidant and antimicrobial properties. In previous studies, CBD limited the growth of some bacteria and pathogenic fungi, such as the ones that cause fresh fruits and vegetables to rot.
However, the oily compound needs to be evenly distributed in water before it can be widely incorporated into foods or used for food preservation. One possible way to do this is to encapsulate the CBD molecules in edible polymers. Researchers in Thailand did this by developing a food coating using CBD-filled nanoparticles.
As reported in ACS’ Applied Materials & Interfaces, the researchers encapsulated CBD in poly(D,L-lactide-co-glycolide), a biodegradable polymer used in drug delivery, producing 400-nm-wide particles. They mixed the most stable nanoparticles, containing 20% by weight CBD, with sodium alginate in water. Strawberries were then submerged into solutions containing different amounts of nanoparticles before a second dip into a mixture of ascorbic acid and calcium chloride to turn the colorless 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 because of reduced microbial growth.
The coating with the most CBD-loaded nanoparticles preserved the berries’ dark red appearance, enhanced their antioxidant activity the most and exhibited the largest antimicrobial protection over the storage period, suggesting that this version would lead to the longest shelf life.
The researchers say that their results demonstrate how encapsulated CBD could be used to create a colorless antimicrobial coating for active food packaging.