engleski

Evaluation of barrier properties and overall migration in polymer buckets intended for pastry fillings packaging

Barrier (gas and water vapour) and migration properties of polypropylene (PP) round bucket with cover bi-foil made of oriented poly(ethylene- terephthalate)/polypropylene (OPET/PP) used for packaging of pastry fillings were evaluated in this study. Barrier performance can significantly impact the stability of packed product and whenever a food is in a direct contact with packaging material, a risk of chemical contamination into food might occur [1]. The gas permeability (O2 and CO2) was measured in OPET/PP films at 3 temperatures (20, 40 and 60 °C). Solubility (S), diffusivity (D) and permeability coefficients (P) of O2 and CO2 were estimated based on the time lag values. Foils were also tested for their water vapour permeability (WVP) at two relative humidity differentials (Δ70% and Δ20%). The total amount of chemical migrants (the overall migration, OM) from buckets and foils was evaluated. Since this packaging is aimed for packing of pastry fillings, 20% (v/v) ethanol (EtOH) and 3% (w/v) aqueous acetic acid (HAc) were chosen as food simulants [2]. Possible structural changes on polymer surface after exposure to food simulants was measured by FTIR. Gas permeability measurements showed higher permeability for O2 than for CO2 with important impact of temperature for both tested gases. Even though at 60 °C P- value was slightly higher, this parameter remained below 100 cm3m-2d- 1bar-1 at 20 and 40 °C confirming that used OPET/PP foils presented an adequate gas barrier for the intended use. The OM values from buckets were below the overall migration limit set by EU legislation.

gas barrier ; water vapour ; migration ; PP ; OPET/PP

nije evidentirano