Effect of calcium and/or barium crosslinking on the physical and antimicrobial properties of natamycin-loaded alginate films

Abstract

The preparation of alginate films with suitable properties requires a two-step contact with reticulating agents: initially a weakly structured pre-film is formatted which is further crosslinked in a second stage by immersion in a more concentrated solution. The present work evaluated the effects of a combined crosslinking procedure using calcium and barium ions on the physical and morphological properties of alginate-based films containing natamycin as antimicrobial agent. The release behavior of natamycin in water was evaluated as well as the antimicrobial activity against four target microorganisms, which are common cheese product contaminants. Films attributes were affected by the type of ion used in the second stage while the natamycin release rate and the antimicrobial activity were influenced by the ion used in the first stage. Films crosslinked with Ba 2þ in the first and Ca 2þ in the second stage (BaeCa films) exhibited physical properties very similar to films crosslinked with calcium in both stages. Release kinetics of natamycin in water fitted well to Fick's second law diffusional model, with effective diffusivity values ranging from 0.40 Â 10 À11 to 1.74 Â 10 À11 cm 2 /s. BaeCa films presented the lowest natamycin diffusion coefficient and the smallest inhibition zone diameter against the four microorganisms tested.

Microstructure of transglutaminase-induced gelatin-natamycin fungistatic composite films

“…The peak appearing at 3080 cm −1 was related to polar interactions between films and unbounded water present in the composite films. [39] The crosslinking using TGase would promote growth in polymer intermolecular hydrogen bonding, which is consistent with the increase in moisture content with the content of TGase increasing. For the signals of acylamino I and acylamino II, the intensities increased, indicating the formation of transamination and molecule aggregation caused by TGase.…”

Alginate and carboxymethyl cellulose in monolayer and bilayer films as wound dressings: Effect of the polymer ratio

“…CMC materials are reported to have a high FA capability . On the other hand, crosslinked alginate‐based materials present a low FA capability because of a lower intermolecular spacing between the polymer chains . This FA characteristic was also encountered in this study (Table ); an increasing tendency ( p > 0.05) for FA was observed with increasing CMC content in the films.…”

Influence of natamycin loading on the performance of transglutaminase‐induced crosslinked gelatin composite films

“…The hydrogen bonds produced by natamycin could impact the thermal stability. This behaviour is consistent with the literature about natamycin‐loaded alginate films (Bierhalz et al ., ).…”