Edible food wrapper
doi:10.1038/nindia.2012.11 Published online 24 January 2012
Researchers have synthesized a new type of edible and biodegradable film by smearing bacteria-derived cellulose nanocrystals in gelatin. The film could be used in the food packaging industry to protect food products from external effects such as moisture.
Biodegradable polymers are gaining importance for the development of edible films, which could reduce packaging waste created by non-degradable petroleum-based food packaging materials. Although gelatin has emerged as promising edible coating because of its nutritional value, it has poor mechanical properties and an affinity towards water.
To design better edible films, the researchers used a bacterium called Gluconacetobacter xylinus to produce cellulose, which was converted into rod-shaped cellulose nanocrystals through acid hydrolysis. They then mixed the cellulose nanocrystals with gelatin to yield a nanocomposite.
The dispersion and distribution of bacterial cellulose nanocrystals was uniform throughout the polymer matrix, forming a sheet-like network within the matrix of gelatin. The cellulose nanocrystals in the gelatin matrix acted as reinforcing components, resulting in better mechanical strength.
The presence of bacterial cellulose nanocrystals in the gelatin matrix reduced its sensitivity to water and increased its resistance to moisture, which is an essential property for any material used in food packaging. The bacterial cellulose nanocrystals also exhibited high thermal stability.
"The nanocrystals obtained from bacterial cellulose are capable of improving the properties of biopolymers such as gelatin, resulting in high-performance edible films," says lead researcher Johnsy George. This type of film could be used to extend the shelf life of different food materials, especially fruits and vegetables, he adds.
The authors of this work are from: Defence Food Research Laboratory, Siddarthanagar, and Sri Jayachamarajendra College of Engineering, Mysore, India.
- George, J. et al. High performance edible nanocomposite films containing bacterial cellulose nanocrystals. Carbohydr. Polymer. 87, 2031-2037 (2012) | Article |