BACKGROUND
Sakacin‐A due to its specific antimicrobial activity may represent a good candidate to develop active packaging solutions for food items supporting
Listeria
growth. In the present study a protein extract containing the bacteriocin sakacin‐A, produced by
Lactobacillus sakei
Lb 706 in a low‐cost culture medium containing deproteinized cheese whey, was adsorbed onto cellulose nanofibers (CNFs) to obtain an active material to be used as a mat (or a separator) in direct contact with foods.
RESULTS
The applied fermentation conditions allowed 4.51 g L
−1
of freeze‐dried protein extract to be obtained, characterized by an antimicrobial activity of near 16 700 AU g
−1
, that was used for the preparation of the active material by casting. The active material was then characterized by infrared spectra and thermogravimetric analyses. Antimicrobial trials were carried out
in vitro
using
Listeria innocua
as indicator strain; results were also confirmed
in vivo,
employing smoked salmon fillets intentionally inoculated with
Listeria innocua
: its final population was reduced to about 2.5—3 Log cycles after 28 days of storage at 6 °C in presence of sakacin‐A, compared with negative control mats produced without the bacteriocin extract.
CONCLUSION
This study demonstrates the possibility of producing an antimicrobial active material containing sakacin‐A absorbed onto CNFs to decrease
Listeria
population in smoked salmon, a ready‐to eat‐food product. © 2019 The Authors.
Journal of The Science of Food and Agriculture
published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.