Author(s): Marques, Arlete Maria Lima
Date: 2016
Persistent ID: https://hdl.handle.net/1822/47396
Origin: RepositóriUM - Universidade do Minho
Subject(s): Bacteriophage ΦIBB-PF7A; Active packaging; Antibacterial activity; Pseudomonas fluorescens; Polysaccharide; Bacteriófago ΦIBB-PF7A; Embalagens funcionais; Pseudomonas fluorescens; Atividade antimicrobiana; Polissacarídeos
Recently, edible packaging materials experienced a notable growth, being expected an important impact in the food industry in the next years. Also, bacteriophages have been recognized for their potential as biotherapeutic agents to control bacterial growth, and their use in food industry to control microbiogical growth has been presented as one of the solutions to maintain food quality. The main aim of this work was the functionalization of edible packaging materials with the use of phages. For the development of edible packaging, different types (Protanal SF 120RB; Protanal CR 8223; Protanal LFR 5/60; Protanal GP 1320 and Protanal Manugel) and concentrations (2.5 g/L, 5 g/L, 7.5 g/L, 10 g/L and 15 g/L) of sodium alginate were evaluated, being a concentration of 10 g/L of alginate CR 8223 and Manugel sellected. The produced films were crosslinked with different concentrations of CaCl2 (0 g/L, 10 g/L, 12.5 g/L and 15 g/L). The films were characterized in terms of moisture content, solubility, contact angle, isothermic adsorption, swelling behaviour, colour and opacity, and mechanical properties (TS and EB), being their chemical structure studied by Fourier Transform Infrared (FTIR) spectroscopy. During characterization of CR 8223 and Manugel alginate films, it was possible to conclude that crosslinking has a significant effect on alginate structure and properties. Characterization of films allows to conclude that crosslinking decreases film thickness and the moisture content of films. It was also possible to notice that crosslinking does not change the films colour, but make them stronger and insoluble with a high swelling index. After the characterization, a concentration of 10 g/L of CR 8223 alginate was selected for phages incorporation, being crosslinked with 10 g/L of CaCl2. The choice was based on swelling and solubility films properties. Antimicrobial activity of alginate films with entrapped phages showed that phage ΦIBB-PF7A can be incorporated in alginate-based films and maintain its activity, leading to a bacterial decrease of 4 log for the multiplicity of infection (MOI) of 10 in the first 24 h. It was also possible to confirm that phages are released onto chicken meat, leading to a decrease of Pseudomonas fluorescens contamination. Results show that alginate-based films with phages can be used to control bacterial growth in meat products, presenting a potential interest for the food industry.
