Development of a Liquid Extraction Method and Comparison with Dynamic Thermal Stripping-Thermal Desorption (DTS-TD) Method: Sorption of D-Limonene by Flexible Packaging Films

摘要

The sorption of D-limonene into polymeric structures in contact with food simulant liquids (ethanol and acetic acid solutions) was determined using two methods, liquid extraction (LE) and dynamic thermal stripping-thermal desorption (DTS-TD). The polymeric films studied were PP (polypropylene), PEylon/EVOH/PE (polyethyleneylonlethylene vinyl alcohol/polyethylene) and metPET/VA EVA/LLDPE (metallized polyethylene terephthalatelethylenevinyl acetate/linear low density polyethylene). Our assessment showed that both LE and DTS-TD techniques are valuable procedures. LE was evaluated as an alternative method with the advantage of being a simplified process. It was possible to measure the amount of D-limonene in the polymers using both methods. Correlation between methods was >82% and for the single layer polymers >92%. The respective sorption values obtained by the two methods were also found to be in good agreement. LE is simple and rapid to perform and, in general, gives slightly lower results compared to DTS-TS sorption tests conducted with adequate food simulants. The results indicate that the liquid extraction method is an excellent technique for the determination of sorbate concentration in polymeric structures.