Effect of relative humidity on the migration of benzophenone from paperboard into the food simulant Tenax® and modelling hereof
The aim of this study was to investigate the effect of relative humidity on the migration of benzophenone from paperboard into the food simulant Tenax®. Kinetic migration investigations were carried out with three relative humidities in the interval between 39% and >73%. All investigations were carried out at a constant temperature of 34°C. It was found that the migration of benzophenone after more than 30 days was 4.8 times higher at a relative humidity of 64%–71%, and 7.3 times higher at a relative humidity of >73%, compared with that at a relative humidity of 39%–49%. Diffusion and partition coefficients were derived from the results by using a software for modelling migration in multilayer materials. Both the diffusion coefficient and the partition coefficient, between paperboard and Tenax®, decrease with increasing relative humidity. The experimental results were correctly modelled only when the paperboard was regarded as a one-layer system as compared with a two-layer system: where the main part of the paperboard (B1) has a high diffusion rate and a thin part of the paperboard (B2) in contact with the foodstuff has a lower diffusion rate.
A portable gas chromatograph with simultaneous detection by mass spectrometry and electroantennography for the highly sensitive in situ measurement of volatiles
Mating disruption is a sustainable method for the control of insect pests, involving the release of synthetic sex pheromones that disrupt the olfactory localization of females by males. However, the development and refinement of this strategy is hampered because current instruments lack the sensitivity to detect volatile organic chemicals in the field, and portable electroantennograms produce non-comparable relative units and distorted results in the presence of plant volatiles. To address the demand for more sensitive instruments that are suitable for the rapid in situ detection of airborne pheromones, we have developed a portable, automated needle trap device connected to a gas chromatograph, mass spectrometer, and electroantennographic detector (NTD-GC-MS/EAD) suitable for field applications. We tested the instrument by measuring the concentration of the sex pheromone (E,Z)-7,9-dodecadienyl acetate, which is used to disrupt the mating of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae). Our data confirm that the instrument generates highly reproducible results and is highly sensitive, with a detection threshold of 3 ng/m3 (E,Z)-7,9-dodecadienyl acetate in outside air.
Cytotoxicological safety assessment of papers and boards used for food packaging.
Because of the lack of information about the possible transfer of toxic compounds from papers and boards to food, the overall cytotoxicity induced by six papers and 15 boards was investigated from water extracts prepared according to the European prestandard. Cytotoxicity measurements were based on RNA synthesis rate of human HeLa S3 cells. The tested virgin and recycled papers and boards were differentiated and classified according to their cytotoxicological quality, which ranged from absence of any cytotoxic effect to severe inhibition of RNA synthesis rate. The cytotoxicity level also varied according to the total amount of compounds detected by gas chromatography. No correlation was found between cytotoxicity and endotoxins contained in the samples. No significant difference in cytotoxicity was observed between the papers and boards produced from virgin fibres and from recycled fibres. Moreover, the products obtained from chemical pulp showed lower cytotoxicity than the products based on mechanical pulp. More generally, the cytotoxicological approach is promising for monitoring paper/board treatment-induced problems. Further work is required to assess a modified standard procedure for the preparation of water extracts specifically adapted to paper/board.