Influence of natamycin loading methods on the physical characteristics of alginate active films

Abstract

a b s t r a c tNatamycin, an antimicrobial agent sparingly soluble in water, was incorporated into alginate films in order to produce antimicrobial packaging, using three different approaches: the conventional loading method, when natamycin is added directly to the polymeric aqueous film-forming solution; the immersion procedure, by which a previously prepared films is contacted with natamycin solution, and by the supercritical solvent impregnation (SSI) method, with loading tests performed in CO 2 containing natamycin, with and without addition of cosolvent (ethanol, 10% molar). The loading capacities were evaluated, as well as the influence on physical attributes of the films and on the release behavior of natamycin in water. The conventional method led to films heterogeneities with high surface roughness, and the immersion technique evinced several disadvantages like low incorporation yields, and negative influence on water vapor permeability and on the swelling degree of the film. The supercritical method showed that longer contact times and the use of ethanol as a cosolvent increased the natamycin loading yields and led to homogeneous films, where SSI (CO 2 + EtOH) process produced visually attractive and tranlucent films.

Impregnation of cellulose acetate films with carvacrol using supercritical carbon ioxide

“…Table 1 also reveals that the Korsmeyer-Peppas release exponent n is above 0.43 indicating that the carvacrol release occurred by anomalous non-Fickan transport. Bierhalz et al suggested that natamicin release from the alginate film was in accordance with the Fickan diffusion [24]. Milovanovic et al [19] also showed that the mechanisms of release of thymol from CA beads followed Fickan and non-Fickan diffusion depending on the thymol impregnation yields as well as the release medium.…”

Improvement of physcio-chemical and functional properties of alginate film by Acacia lignin

“…2) (Bierhalz et al, 2013;Papageorgiou, Kouvelos, Favvas, & Sapalidis, 2010). The following absorption bands in the region from 1600 to 1300 cm À1 were assigned to stretching vibrations of carboxylic groups.…”

“…It is a linear copolymer of (1-4)-linked b-Dmannuronate (M) and a-L guluronate (G) units, arranged as homopolymeric blocks (Poly-M and Poly-G) (Bierhalz, da Silva, de Sousa, Braga, & Kieckbusch, 2013). It has certain unique properties, such as biocompatibility, non-toxicity, hydrophobicity, and chelating ability (Derkus, Emregul, Emregul, & Yucesan, 2014).…”

“…Addition of antimicrobial and antioxidant agents is helpful in maintaining shelf life and improving food safety by killing or inhibiting spoilage and pathogenic micro-organism causing contamination of food (Bajpai, Chand, & Chaurasia, 2012). Alginate films are also incorporated with plant extract such as aloevera and drug like natamycin to expand their functional properties (Bierhalz et al, 2013;Pereira, Carvalho, Gil, Mendes, & Bartolo, 2013). Among various antimicrobial agents, fluconazole is a bis-triazole synthetic compounds that exhibits broad spectrum of antifungal activity belonging to the group of trizole.…”

Antimicrobials Used in Active Packaging Films

“…Also, in another research it was notified that the addition of potassium sorbate in films, it has caused to change water permeability and elongation positively but not in tensile strength (Barzegar, Azizi, Barzegar, & Hamidi-Esfahani, 2014) indicating the effect of antimicrobial type used in film on physical properties of films. Bierhalz, da Silva, de Sousa, Braga, and Kieckbusch (2013) had reported that nisin and natamycin had been added into film matrix resulting in enhancing the water vapor permeability of the films since it might cause micro or macro heterogeneities in polymer structure due to the presence of antimicrobial's (Bierhalz et al, 2013). Unlike tensile properties, it was reported that the loading method of antimicrobial in active packaging films influence the barrier properties of the films.…”