Characterization of κ-carrageenan films incorporated plant essential oils with improved antimicrobial activity

• Published in: Carbohydrate polymers 2014-01, Vol.101, p.582-591
• Main Authors: Shojaee-Aliabadi, Saeedeh, Hosseini, Hedayat, Mohammadifar, Mohammad Amin, Mohammadi, Abdorreza, Ghasemlou, Mehran, Hosseini, Seyede Marzieh, Khaksar, Ramin
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Bacteria - drug effects; Carrageenan - chemistry; Carrageenan - pharmacology; Edible film; Free Radical Scavengers - chemistry; Free Radical Scavengers - pharmacology; Kappa-carrageenan; Mechanical Phenomena; Mentha pulegium; Oils, Volatile - chemistry; Permeability; Phenols - chemistry; Plants - chemistry; Structure-Activity Relationship; Vapor phase; Volatilization; Water - chemistry; Zataria multiflora Boiss
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2013.09.070

•The addition of essential oils in particular ZEO reduced WVP of films.•Mechanical properties of emulsified carrageenan films were enhanced.•MEO and especially ZEO improved the antioxidant properties of the carrageenan films.•The composite emulsified films effectively inhibited the five pathogens tested.•ZEO can be incorporated into carrageenan to produce antimicrobial films. Antioxidant and antimicrobial kappa-carrageenan-based films containing different concentrations of Zataria multiflora Boiss (ZEO) and Mentha pulegium (MEO) essential oils were developed, and their water vapor permeability (WVP), optical, microstructure, antioxidant and antimicrobial properties were characterized. ZEO and MEO decreased the WVP of the emulsified films; for example, 3% ZEO reduced WVP by around 80%. Increasing the content of ZEO or MEO from 1% to 3% (v/v) increased values for elongation at break from 37.43% to 44.74% and from 36.09% to 41.25% respectively. Carrageenan-composite films were less resistant to breakage, more flexible and more opaque with lower gloss. These properties were related to the film's microstructure as analyzed by atomic force microscopy and scanning electron microscopy. ZEO affected the antioxidant properties of the films more markedly than MEO, e.g., ZEO containing films showed DPPH radical scavenging of 80.6% which were two-fold higher than those having MEO. The films’ antimicrobial activities were increased by incorporating essential oils, particularly ZEO, which were more effective against the bacteria in the direct-contact method than a vapor phase. S. aureus was found to be the most sensitive bacterium to either ZEO or MEO, followed by B. cereus and E. coli. A highest inhibition zone of 544.05mm2 was observed for S. aureus around the films incorporated with 3% (v/v) ZEO. The total inhibitory zone of 3% (v/v) MEO formulated films was 20.43 for S. typhimurium and 10.15mm2 for P. aeruginosa. These results revealed that ZEO and MEO have good potential to be incorporated into κ-carrageenan to make antimicrobial and antioxidant edible films for food applications.