A group of researchers at the University of Tabriz, northwestern Iran, produced a biodegradable nanocomposite for food packaging.
Being antimicrobial and water-vapor-resistant, the new packaging increases the safety and shelf life of foodstuff, ISNA reported.
Biopolymers forming biodegradable films can be composed of protein, polysaccharide, fat or a combination of all three, said Dr. Mahdieh Salari, who holds a PhD of Food Science and Engineering from the University of Tabriz.
‘Chitosan’ is one of polysaccharide biopolymers which is widely used for producing biodegradable films, Salari said, adding despite its numerous advantages and unique properties, applying chitosan film is restricted due to its inherent sensitivity to water and relatively weak mechanical characteristics.
She suggested that an appropriate way to improve the properties of chitosan film is mixing it with a reinforcing nano-filler and forming a nanocomposite.
Salari noted that in this study, attempts have been made to combine bacterial cellulose nanocrystal and silver nanoparticles with biopolymer, thus synthesizing a nanocomposite film that has antimicrobial properties and leads to an increase in food shelf life.
The researcher added that employing bacterial cellulose nanocrystal has a great influence on the film’s thermal and mechanical properties as well as its resistance to water vapor.
“In addition, applying silver nanoparticles significantly improves antibacterial characteristics of chitosan film against gram-positive and gram-negative bacteria as well as fungi.
The initiative’s advantage over other studies lies in its application of bacterial cellulose instead of plant cellulose to produce cellulose nanocrystal, she boasted.
“In this project, bacterial cellulose has been produced using auxiliary products of food industry firms as a culture to grow bacteria. This reduces the costs involved in cellulose production and helps make optimum use of the firms’ foodstuff to make a valuable biotic material.”
The results of the project have been published in Food Hydrocolloids Journal.