Abstract
Background: Biopolymer based films can satisfy the consumer demand for ecologically safe food packaging material. Functional compound(s) can be added to matrix biopolymer to obtain active packaging material.
Objective: This study aimed at developing active film using blends of wheat gluten and corn zein. The usability of green tea extract as active component to prevent oxidation in packed food was also evaluated.
Method: Composite films of zein and gluten in the ratio 1:1, 1:2, and 1:3 were prepared by dissolving the polymers in required quantity in ethanol. The solutions were homogenized, degassed, casted and dried at 50˚C and 50% RH. Green tea extract (GTE) was used as active component in these films.
Result: The zein films were homogenous but brittle, while gluten films were flexible. Blending resulted in easy to handle films. Transparency of composite films improved with increasing proportion of gluten. The ability to block UV light was not affected by blending the polymers. Tensile strength of the composite films did not vary with varying composition of films but improvement in percent elongation was observed with increasing proportion of gluten. The solubility of the films reduced as the proportion of gluten in the matrix increased without affecting water vapour permeability. Incorporation of GTE did not affect optical and mechanical properties and imparted antioxidant properties to the film. The active films inhibited lipid peroxidation in meat system.
Conclusion: These films show good potential as active packaging material for prevention of oxidative changes in meat.
Keywords: Active packaging, antioxidant films, gluten, green tea, lipid peroxidation, zein.
Graphical Abstract
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