A team of researchers have used a mixture of cannabidiol (more commonly known as CBD) and sodium alginate to extend the shelf-life or strawberries by creating a colourless, edible antimicrobial coating.
CBD has seen a recent uplift in popularity due to its perceived health benefits, with the UK market valued at £690m in 2021 – an increase of 119.75% from 2019. But according to the Thailand-based team, it has also been shown to possess antioxidant and antimicrobial properties.
In previous studies, CBD has limited the growth of some bacteria and pathogenic fungi, including the ones that cause fresh fruit and vegetables to rot. However, for wide use in foods or food preservation, the oily compound needs to be combined with water. One possible way to do this is to encapsulate the CBD molecules in edible polymers.
In their experiment (paper cited below1), which comprised researchers from departments at Thammasat University, the Chulabhorn Research Institute, and Chulalongkorn University, the team investigated whether a food coating using CBD-filled nanoparticles could indeed promote antimicrobial activity and lengthen the life of strawberries.
The researchers used poly(D,L-lactide-co-glycolide), a biodegradable polymer to encapsulate the CBD. They mixed the most stable nanoparticles, containing 20% by weight CBD, with sodium alginate in water. The strawberries were dipped into the solutions containing varying levels of nanoparticles before being submerged into a combination of ascorbic acid and calcium chloride which transformed the coating into a gel.
The researchers stored untreated and coated strawberries in open plastic containers in a fridge. After 15 days, it was found that the treated samples were ripening and decaying must slower.
The coating with the most CBD-loaded nanoparticles were found to have preserved the berries’ dark red appearance and enhanced their antioxidant activity.
The hope is that this could lead to the creation of a colourless coating for active food packaging.
The study was published in ACS Applied Materials & Interfaces.
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- ACS Appl. Mater. Interfaces 2023, 15, 19, 23834–23843. Publication Date: May 4, 2023. https://doi.org/10.1021/acsami.3c04036