engleski

Oxygen permeability of high barrier food packaging film after ultrasound treatment

Ultrasonic waves can be readily propagated through certain optically opaque materials including many foods and packaging materials. For food products expected to exhibit extended shelf-life, a loss of packaging integrity may be a precursor to major food safety and quality issues. Coated (acrylic/ polyvinylidene chloride) biaxially oriented transparent polypropylene (BOPP/Ac/PVDC) films was treated for 2, 4 and 6 minutes with power ultrasound, high intensity and low frequency, 20 kHz probe with constant amplitude of 50%, 75% and 100% (S-4000, Misonix Sonicators, Newtown, Connecticut, SAD). The oxygen permeability, using a Brugger (GDP-C model) permeability tester, of the BOPP/Ac/PVDC was analysed at 20/40/60 °C. The permeability (P), the diffusion (D) and the solubility (S) constants of the oxygen in BOPP/Ac/PVDC film was determined before and after ultrasound treatments. Ultrasound treatment (6 min., 50% amplitude) increased oxygen permeability of BOPP/Ac/PVDC film from 3.8 cm3/m2.d. bar (non- treated sample) to 57 cm3 /m2.d. bar, at 20°C. BOPP/Ac/PVDC film, treated at 2 min. with 100% amplitude, showed increased oxygen permeability from 290 to 330 cm3/ m2.d. bar at 60°C. The present work has clearly illustrated that the structure of the BOPP/Ac/PVDC film was damaged leading to the gas barrier degradation of coated polypropylene film.

ultrasound; polypropylene; oxygen permeability

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