Whey, a disposable remainder obtained during the production of cheese for a long time, became a valuable by-product because it can be an excellent base for developing protective films for food packaging providing alternatives to petroleum-based plastics, which are harmful to health and to the environment in general.
Whey protein-based films for food packaging also have the advantage of being edible and biodegradable, unlike the plastics currently used.
One of the most recent studies carried out in America assessed the properties of active whey protein-based films for food when accompanied by Natamycin, an emulsion of the antioxidant α-tocopherol (vitamin E), and both together.
Four films were prepared with different levels of Natamycin and α-tocopherol, and were characterised in terms of their antioxidant and antimicrobial activity properties, among other features.
The F0 films did not contain either Natamycin or tocopherol, F2 and F3 contained Natamycin and F3 also contained tocopherol.
The image below shows the effectiveness of Natamycin and the antioxidant against contamination by bacteria, specifically C. albicans, P. chrysogenum and S. cerevisiae.
The round “patches” on the F0 plates are barely visible, because microorganism populations are growing all over the plate. Meanwhile, on the F2 and F3 plates, growth inhibition halos for each contaminating microorganism species have formed around the round patches that now contain Natamycin.
It can also be seen that tocopherol does not interfere with the effect of Natamycin, because the designs from samples F2 and F3 are practically the same.
The use of Natamycin and anti-oxidant together for packaging films is a good alternative, as shown by the results obtained in this research.
Good results for many of the expected characteristics of food protection films were obtained from this test.
The results were optimal for protection against UV radiation, humidity, oxidation and bacterial contamination, among other problems.
As is apparent, the area with the coloured bars showing Natamycin has the most dark blue squares. This result once again confirms the greater efficacy of Natamycin, while the other substances slow down growth of mould to a lesser extent, even when applied in higher doses.
Other important characteristics in these types of packaging were also studied: the thickness of the film, its moisture content, its solubility in water, its mechanical properties, etc.
All these parameters are essential if this type of packaging is to be attractive to the food industry.
What the industry requires is a guaranteed optimal conservation of food during its distribution and consumption, with the environmental sustainability factor that only this packaging can provide.