A new study has explored how rapeseed processing waste could be developed into a biodegradable food packaging film to protect and extend the shelf-life of fresh food.
Published in Food Quality and Safety, the study saw researchers from the School of Biological Engineering at Dalian Polytechnic University, alongside INNOBIO Corporation Limited, explore how extracts from rapeseed cake, flowers, stems and leaves could be combined with chitosan (CS) and biosynthesised silver nanoparticles to create an active packaging material with antioxidant and antimicrobial properties.
Through this process, the researchers used the naturally-occurring phenolic compounds from rapeseed byproducts to strengthen the film and improve its resistance to moisture, oxygen and ultraviolet light.
Chitosan is a natural sugar polymer extracted from crustacean shells, which is used as biodegradable packaging for food products, as well as in the medical care industry. Laboratory tests showed the composite material, incorporating rapeseed waste, significantly outperformed conventional chitosan films.
Food packaging
‘Modern food packaging must protect products from moisture, oxygen, light, oxidation, and microbial spoilage, yet conventional plastics persist in the environment after disposal,’ the researchers noted.
‘Bio-based films offer a renewable and biodegradable alternative, but CS films often lack the mechanical strength, barrier performance, water resistance, and active protection needed for demanding preservation conditions. Rapeseed production also generates cakes, stems, leaves, and flowers rich in cellulose, polyphenols, flavonoids, and other useful compounds, although much of this material remains underused.
‘Based on these challenges, in-depth research is needed to develop strong, multifunctional bio-based packaging that can preserve food while converting agricultural residues into higher-value materials.’
Test process
In food storage tests, coated cherry tomatoes retained more weight, vitamin C and acidity during storage, while packaged enoki mushrooms experienced less browning and microbial deterioration compared with untreated samples.
Environmental testing showed the packaging completely biodegraded in soil within 21 days, with no significant impact.
According to the researchers, the central takeaway from the study is that crop residues can ‘do more than replace part of a packaging material: their natural chemistry can help the package actively protect food‘.
As they note, the technology could be used to develop more sustainable coatings, wraps, or liners for fresh produce and other foods vulnerable to spoilage, while also creating new value from rapeseed processing residues, which remain typically under-utilised. Read more here.
