To evaluate the antimicrobial activity of the films in packaged
salads 1, 3, 5 and 7 days after packaging, the ISO 4833-2:2014
guidelines with modifications were performed. Three samples per
treatment (PLA and PLA containing 2, 5, 6.5% Proallium®) were
developed, and the original microbial counts of each iceberg salad
packaged in contact with different PLA films were measured.
Samples of precut ready-to-eat packaged salad (25 g) were diluted
in 225 mL of peptone water (Merck-Spain, Madrid, Spain) and
homogenised in a masticator blended (IUL, Barcelona, Spain) for
2 min. Different dilutions were made in sterile saline solution, and
0.1 mL of each dilution was seeded in plates with a Digralski
spreader.