Alginate–Arabinoxylan Composite Films with Enhanced Mechanical Strength and Functional Properties for Potential Food Packaging Use

The concern about plastic pollution drives the exploration of sustainable and environmentally friendly packaging materials. Alginate is a renewable, edible feedstock extracted from seaweed, which has been used for preparing edible biofilms. The major limiting factor in alginate biofilms wider application is that it is relatively weak in strength. This study explored a novel alginate composite biofilm prepared using alginate and maize bran derived arabinoxylans. In comparison with alginate alone, adding 2.5% w/w maize arabinoxylans increased the tensile strength of the film by 3.1 times. Using an optimized composition (2.5% alginate, 1% glycerol and 1.5% maize arabinoxylans), the tensile strength and elongation of the biofilm increased to 4.9 and 3.0 times that of alginate only biofilm to 6.88 ± 0.06 MPa and to 96.4 ± 9.9%, respectively. Interestingly, the water-holding capacity of biofilm increased from 5.5 times weight of water for 5 min for alginate alone biofilm to 27.6 times the weight of water for 50 min. When 0.5% clove essential oil was incorporated into the composite film, the biofilm exhibited excellent anti-microbial property, keeping raw meat free of bacteria for five days in both refrigerated and open environments. These results indicate that the alginate-based bio-composite film is a promising candidate for food packaging.