Novel Way to Develop Active Food Packaging Using Wheat Straw and Mango Peels
Scientists from Stellenbosch University (SU) have discovered a way to use wheat straw and mango peels in the development of renewable, biodegradable and non-toxic, active food packaging that could help keep products fresher for longer.
“There's a move towards renewable and biodegradable food packaging in a bid to replace non-renewable and non-biodegradable petroleum-based packaging materials. We should consider using agricultural-residues like wheat straw and mango peels, which are rich in bio or natural polymers and antioxidants, as alternative raw materials to petroleum-based packaging materials," says Dr Lindleen Mugwagwa, Department of Process Engineering at SU.
Extracting Biopolymers and Antioxidants
Mugwagwa's study was the first to develop methods for extracting the necessary bio or natural polymers and antioxidants from both wheat straw and mango peels that contain properties that are suitable for developing an active food packaging material. It was also the first time that these products were integrated to form a biocomposite film that was tested in a food environment.
As part of the study, researcher developed and optimized processes for extracting these polymers and antioxidants. The polymers and antioxidants were then combined to make a food packaging material and tested the stability of the biocomposite films when in contact with food as well as their potential to release antioxidants into packaged food over time. Low-density polyethylene film, a commonly used plastic, was used as a benchmark.
The study showed that the properties of polymers and antioxidants in wheat straw and mango peels can be tailor-made during extraction to suit their application in food packaging. The polymers and antioxidants can be extracted simultaneously from the same feedstock without affecting their use in food packaging.
Ideal Packaging for Perishables
“The bio-based films that I developed were capable of releasing more antioxidants into food over a short time when compared to low-density polyethylene plastic. This suggests that they can be a replacement for packaging perishables,” says Mugwagwa.
“The release of antioxidants into food by packaging material is becoming an important aspect to consider when choosing packaging material. Packaging material capable of releasing antioxidants into food in response to storage conditions has the potential to increase the shelf life of products because the released antioxidants act upon free radicals and microorganisms which may develop when food is improperly stored or when food is stored for longer periods."
“My research provides cheap, sustainable and biodegradable polymers that can be used in the development of food packaging and presents methods for recovering natural antioxidants and their application as additives to food packaging material. These natural antioxidants have the potential to replace artificial antioxidants in packaging material that could cause cancer."
The type of food packaging material proposed in the study could be ideal to replace environmentally hazardous petroleum-based packaging materials. The research can benefit biorefineries, the food packaging industry as well as farmers and consumers.