Films based on Pectin, Gellan, EDTA, and bacteriocin‐like compounds produced by Streptococcus infantarius for the bacterial control in fish packaging

• Published in: Journal of food processing and preservation Vol. 45; no. 1
• Main Authors: Pérez‐Arauz, Ángel‐Omar, Rodríguez‐Hernández, Adriana‐Inés, Rocío López‐Cuellar, Ma, Martínez‐Juárez, Víctor‐Manuel, Chavarría‐Hernández, Norberto
• Format: Journal Article
• Language: English
• Published: 01-01-2021
• Subjects: bacteriocins; fish conservation; functional films; gas permeability; lactic acid bacterium; mechanical properties; tilapia; trout
• ISSN: 0145-8892; 1745-4549
• DOI: 10.1111/jfpp.15006

A fish‐packaging film was prepared with 0.4% gellan gum (GG), 2% citrus pectin (CP), 0.75% glycerol, EDTA 1 mM, and 50 arbitrary‐units (AU)/ml of antimicrobial‐activity supernatants (AS) from Streptococcus infantarius cultures containing bacteriocin‐like compounds of 5–10 kDa. The formulation was based on a minimum inhibitory condition (AS, 50 AU/ml; EDTA, 1 mM; CP, 0.1%; GG, 0.05%) for 105 CFU/well of Escherichia coli, Staphylococcus aureus or Listeria monocytogenes growing in BHI at 35°C, 24 hr. The films entirely inhibited the growth of the three bacteria in two model fish media, containing trout or tilapia, at two incubation‐conditions: 9°C, 90% RH, 30‐day; and 35°C, 35% RH, 7‐day. Furthermore, wrapped fresh‐fillets of trout or tilapia exhibited the lowest total‐aerobes counts, 8 × 106–1 × 107 CFU/g, after 7‐day‐incubation at accelerated conditions (25 ± 2°C, 60 ± 10% RH), showing the film‐potential. The film‐physical‐mechanical properties (Young’s modulus; elongation and stress at break; oxygen and water vapor permeability) were slightly affected by the EDTA‐AS contents.
Practical applications
Development of a biodegradable‐film based on citrus pectin, and gellan gum, enriched with EDTA and antimicrobial substances produced by Streptococcus infantarius, for hindering the growth of pathogen bacteria (i.e., Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes) and total aerobes that would contaminate and/or deteriorate fresh fish, like trout and tilapia.