Strategies to improve the mechanical strength and water resistance of agar films for food packaging applications. (5th November 2015)

• Record Type: Journal Article
• Authors: Sousa, Ana M.M.; Gonçalves, Maria P.
• Is Part Of: Carbohydrate polymers. Volume 132(2015)
• Page Start: 196
• Page End: 204
• Publication Date: 2015-11-05
• Subjects: Native agar -- Alkali-modified agar -- Locust bean gum -- Packaging films -- Synergisms -- Integrated multi-trophic aquaculture; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.06.022
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Agar solutions easier to process with locust bean gum (LBG) addition (viscosity increase and decrease in gelling ability). Film-forming properties of native (NA) and alkali-modified (AA) agars clearly improved by LBG addition. NA/LBG films exhibited similar or better properties than AA/LBG films. NA/LBG films are more cost-attractive for the transformation industries. Integrated multi-trophic aquaculture can enable tunability and quality control of biomass for transformation industries. Abstract: Agar films possess several properties adequate for food packaging applications. However, their high cost-production and quality variations caused by physiological and environmental factors affecting wild seaweeds make them less attractive for industries. In this work, native (NA) and alkali-modified (AA) agars obtained from sustainably grown seaweeds (integrated multi-trophic aquaculture) were mixed with locust bean gum (LBG) to make 'knife-coated' films with fixed final concentration (1 wt%) and variable agar/LBG ratios. Agar films were easier to process upon LBG addition (viscosity increase and gelling character decrease of the film-forming solutions observed by dynamic oscillatory and steady shear measurements). The mechanical properties and water resistance were optimal for films with 50 and/or 75% LBG contents and best in the case of NA (cheaper to extract). These findings can help reduce the cost-production of agar packaging films. Moreover, the controlled cultivation of seaweeds can provide continuous and reliable feedstock for transformation industries.