Chitosan: A Solution for Food Packaging

As we are moving forward the problems related to environment are increasing and one of the major issue faced by food industry is packaging. The impact of packaging on environment as well as on food are well known. Due to the presence of petroleum based chemicals and bisphenol A, the non-biodegradable packaging might be toxic in nature and can contaminate the food as well as water.

So it is best to find an alternative to such problem. There are many alternatives such as edible packaging, biodegradable phenols, biodegradable starch blends, etc. but today we are going to talk about Chitosan a compound used to make all these films, which is derived from chitin after deacetylation. It has earlier being used in many industries such as medicines, environment, bioengineering, etc. due to its properties. Chitosan has excellent properties of antimicrobial activity, nontoxicity, biocompatibility, biodegradability, chelating capability, etc.

Why I said it’s a solution for packaging industry because there have been many trends in which chitosan can be fabricated into films and being used in food packaging. Chitosan films can be used for increasing the shelf life of the food material due to its antimicrobial property and it can also be used in different forms such as pure chitosan films, chitosan/synthetic films, chitosan/biopolymer film, chitosan derivative film, etc. With such wide variety of film available there is no doubt that chitosan films are the solution for food packaging industry.

So let’s talk about the variety of films in detail:

        Pure Chitosan Films

These films are edible in nature i.e. they come under the category of edible films. The development of such films is relatively easy as chitosan easily dissolves in acid solution (such as acetic acid) they can be fabricated into films. These films are generally used for preservation purpose. Varity of foods have been preserved using this film, this includes tomato, banana, pomegranate, carrot, mango, fish, etc. Moreover, these pure chitosan films have been proven to be able to delay the qualitative and nutraceutical traits changes, prevent the growth of microbial, keep antioxidant activity, and prolong the shelf life.

For increasing the strength, flexibility, extendibility and chain mobility of pure chitosan films, small amount of plasticizers such as sorbitol and glycerol can be added.

         Chitosan/Biopolymer film

Due to characteristic such as biodegradability, non-toxicity, biocompatibility many biopolymers can be combined with chitosan to fabricate the film. This film will have combined characteristic of both the chitosan as well as biopolymer used. Researches were carried out on this and many were successful. Biopolymers like polysaccharide. Proteins, extracts, organic acids, etc. can be used with chitin to form films.

For details of chitosan/biopolymer film... click here.

         Chitosan Synthetic Polymer based films

Chitosan can be blend with synthetic polymer to develop films with improved characteristic and properties. Films will have better mechanical properties depending upon the synthetic polymer used. Due to the presence of chitosan these films will also have antimicrobial property which is best for food packaging. But the problem which arise with these films is that we don’t know whether these films are biodegradable or not. If you know the answer please comment down below.

         Chitosan/Inorganic Material Film

As written above chitosan has high chelating ability, due to this it is easier to blend it with inorganic compounds and form complexes. These films often demonstrate great promises in food packaging. For example, silver nanoparticles, with antimicrobial activities against a wide range of pathogenic microorganisms, could be incorporated into chitosan films for active food packaging. Chitosan and silver nanoparticles could be homogeneously distributed in polymer matrix via a green chemistry methodology. This will enhance the properties such as antibacterial activity, hydrophilic property, degradability, biocompatibility, and nontoxicity of the films consisting of chitosan and silver nanoparticles which will promote its use in food packaging industry.

Let’s take another example, Chitosan/montmorillonite composite films has been widely researched, for the improvement of films barrier (oxygen, carbon dioxide, and water vapour) Some researchers found that the addition of montmorillonite in chitosan films could also enhance mechanical property and improve flame retardant properties, showing benefits for new types of food packaging. More such researches are still going on and more results on the properties of chitosan/inorganic films are being studied.

But there is a concern regarding this film and that is since inorganic material is being added these material can be good for one type of food and unsuitable for other. So while using such films one have to take care of compatibility of inorganic part with food which is being packed.   

 Chitosan derivatives films

Well chitosan can be modified due to presence of large amount of amino and hydroxyl groups and can be converted to chitosan derivatives. These derivatives not only have properties of chitosan but also have additional characteristics due to the modification. Well a good thing is that chitosan can be blended with chitosan derivatives to fabricate edible films. At present, the types of chitosan derivatives applied to food are not much, and more chitosan derivatives with special functions should be explored. Though chitosan derivatives have been produced and applied to film, the production process should be further simplified and the by-products should be minimized. Also, toxicity test should be considered, which a paramount process is before applying to practical market.

Thank you for giving it a read.

For any doubt or question please comment below.