
Edible films and coatings can not only protect food from environmental contamination, but
also control the transfer of moisture, oxygen, carbon dioxide, essence and aroma, reduce the
growth of fungi and bacteria, and improve food nutrition. Appearance and structural integrity;
in addition, they can obtain different functional properties depending on the properties of their
constituent materials. These latter characteristics are influenced by different factors, such as
the type of material used (conformation, molecular mass, charge distribution), conditions under
which these edible films are prepared (type of solvent, pH, concentration, temperature, etc.),
and the type and concentration of additives used in their preparation (plasticizing agents,
crosslinking, emulsifiers, antimicrobials and antioxidants, etc.). (Gil et al., 2016).
Currently, the use of polymers of natural origin for the elaboration of edible films and coatings
is being widely studied and have been applied to different foods, such as meat derivatives,
cereals, nuts, fruits and vegetables. The use of edible films and coatings for food protection
and preservation has many advantages over the use of synthetic materials, mainly because they
are biodegradable and environmentally friendly, in addition to being considered "natural" and
safe. According to Quintero, edible films have been classified according to the structural
material from which they are made, so that there are edible films based on hydrocolloids
(proteins and polysaccharides), lipids and the mixture of hydrocolloids and lipids, called
composite films (composites). On the other hand, antimicrobial agents are components that can
be incorporated into active packaging and/or edible films and coatings, where their
antimicrobial effect is caused by the discharge of volatile substances into the upper space of
the packaging or their migration from the packaging. caused. Food container material.
Currently, volatile antibacterial substances commonly used in the active packaging of products
in the IV range are SO2, ClO2, ethanol, etc., which can be incorporated into packaging to
control the growth of fungi and bacteria. SO2 is incorporated into the packaging material as
metabisulfite, which is very effective against mold growth in fruits. It should be noted that
metabisulfite is a compound that should be handled with certain precautions, because it can
cause irritation, but it does not cause major hazards to consumers.
Other volatile compounds that have received attention for their antimicrobial properties are
hexanal, 1-hexenol, methyl benzoate, 2-nonanone. The latter is a volatile compound found in
the aroma of strawberries that exhibits fungistatic properties, which increases the shelf life of
strawberries and apples. There are also non-volatile antimicrobial agents, such as weak organic
acids (acetic, benzoic, sorbic, citric, propionic, etc.), enzymes (lysozyme, glucose oxidase),
bacteriocins (nisin, pe-diocin), synthetic fungicides (ima-zalil), metals (silver, copper and
zirconium), and natural plant extracts (thymol, carvacrol, eugenol, citral, etc.). (Matiacevich et
al., 2016).
In the manufacture of fresh-cut products, the most commonly used antimicrobial agents are: a)
Citric acid: Inhibits bacterial growth by chelating ions essential for their development. It can
also be used to prevent enzymatic browning because it acts as a copper chelating agent (co-
factor of polyphenol oxidase). Concentrations used range from 0.1 to 0.3% and for antioxidant
action at levels of 100 to 200 ppm.