EFFECT COLD TEMPERATURE AND pH ON PERFORMANCE OF A STARCH-BASED WATERMELON SEED NANOCOMPOSITE FILM FOR LOCUST BEANS PACKAGING
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Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
Carpathian Journal of Food Science and Technology
Abstract
In this research, the performance of starch-based watermelon seed nanocomposite film was evaluated for locust beans packaging under varying pH and temperature conditions. The film was prepared by casting a blend of 15g potato starch, 0.3g watermelon seed nanoparticles with an average size 4.04 nm, 100g glycerol, and 300ml distilled water at 85oC in 300× 150 mm plastic mold. It was characterized to determine its microstructural, thermal, and barrier properties using standard methods. Samples of the locust beans, prepared at 7.22– 11.13 pH range, were wrapped using the film and a low density-polyethylene (LDPE) which serves as a control. The microbial loads were determined after 30 days of storage between 4– 10oC temperatures. Results show ~ 4% loss in weight up to 300oC, thus the film is thermally stable. The permeability coefficients were 0.7× 10-10, 2.15× 10-10 and 22.0× 10-10 cm3 (STP) cm/cm2scm Hg for nitrogen, oxygen, and carbon-dioxide, gases, respectively. Morphologically, the particles in the film are heterogeneously distributed within the matrix, revealing traces of elemental components with average pore size smaller than a water molecule but
sufficient to allow exchange of the gases in the microsphere. There was significant difference (p<0.05) in the level of the microbial loads in the samples packaged using the nanocomposite film compared those packaged using the LDPE. The nanocomposite film is therefore a better packaging material than the LDPE for locust beans packaging under the same pH and temperature.