3.2. Evaluation of the dissemination of the bacteriophage and its
viability in acetate film
We can observe from Fig. 3 that after 14 days of evaluation the
bacteriophage was no longer detected. However, we know that the
shelf life of a refrigerated product is on average 3e10 days. On the
first day after the preparation of the film, the concentration of
bacteriophage is in the order of 108 PFU∙mL1
, and the initial
concentration was 1010 PFU∙mL1
. So initially the bacteriophage
reduced two log cycles and after 14 days it dropped considerably,
reaching non-detectable levels.
In relation to loss of viability of the bacteriophage in the film,
this probably occurred because the film does not come into contact
with food and, consequently, the bacteriophage is not in contact
with the bacteria. The in vitro test was performed without the film
being in contact with food to represent the same conditions. The
release to the environment occurred only during the analysis process,
when the film was stored during this time (14 days). As previous
studies have shown that encapsulation of phages in various
biopolymer matrices lead to significant loss in activity. The dried
microspheres with encapsulated phages were combined with
trehalose, a common stabilizing agent for viruses, to increase the
phage stability after drying (Bieganski, Fowler, Morgan, & Toner,
1998). Similar encapsulation of phages in synthetic PVA (polyvinyl
alcohol) polymer using the electrospinning process has shown a
significant loss in number of viable phages (~1e 6% viable phages)
immediately after electrospinning