Book Chapter Details
Mandatory Fields
Santos E.C. M., *Sousa-Gallagher M.J., Moreira R.A.
2008 September
Valnatura: a Europe-Latin America postgraduate research network in the VALorization of NATURAl resources
Characterization of Galactomannan Edible Films to Extend Shelf Life of Fruits
Universidade do Minho ( Portugal)
Pacos de Ferreira, Portugal
Optional Fields
Edible films and coatings are of interest since they have potential to improve food shelf life and quality and protect food from deterioration by microorganisms and physical damage. However, lack of edible film or coating properties data has limited their use in food applications. Barrier and mechanical properties of edible films or coatings strongly depend on the nature of the materials, extraction process, manufacture of the films and their final compositions. The objectives of this study were to i) characterise the mechanical and barrier properties of galactomannan based edible films as a function of galactomannan and glycerol concentration, ii) evaluate the influence of temperature and relative humidity on the film properties and iii) evaluate film performance to extend the shelf life of fresh cut packed Royal Gala apples. A response surface methodology was applied to determine the formulation, the mechanical and barrier properties and the environmental conditions that can affect film performance. It was found that films with high tensile, elongation and puncture strengths were obtained at higher galactomannan concentration and lower glycerol concentration. Thickness and tear strength increased with galactomannan and glycerol content. Galactomannan and glycerol concentrations influence significantly Water Vapour Permeability (WVP), Oxygen Permeability (OP), Water Uptake (WU) and Moisture Content (MC). The results indicated that glycerol played a major role on the film’s physical-chemicals properties showing a positive effect on the WU, MC and WVP, and negative effect on the OP. The temperature and relative humidity showed a positive highly significant effect on WVP and OP. Apples packed using edible film showed a decrease in weight loss and a delay in the onset of decay as shown by lower colour, pH and moisture content changes during storage of the fruit packed under the conditions tested, confirming the potential application of edible films for extending the shelf life on packaged foods.
Grant Details