100B-7 |
Migration of volatile degradation products into ozonated water from plastic packaging materials |
Y. S. SONG1, F. Al-Taher2, L. Xu3, and G. SADLER2. (1) Food and Drug Administration, National Center for Food Safety and Technology, 6502 S. Archer Rd., summit-Argo, IL 60501, (2) Illinois institute of Technology, National Center for Food Safety and Technology, 6502 S. Archer Rd., summit-Argo, IL 60501, (3) PraxAir, 7000 High Grove Blvd, Burr Ridge, IL 60521 Ozonation is commonly used worldwide for disinfection of drinking water to be held in plastic polymer bottles. Some anecdotal evidence suggest that ozonated bottled water gives more off-taste than does non-ozonated bottled water. This has been attributed to residual ozone attack of chemical bonds. However, scientific information is limited. This research was conducted to measure the migration of volatile degradation products into ozonated water from polyethylene terephthalate (PET) and high density polyethylene (HDPE) bottles, polypropylene (PP) caps and ethylene vinyl acetate (EVA) liners. Polymer strips were immersed in deionized and distilled water with concentrations of 0.5, 2.5, and 5 ppm ozone inside a 35-mL vial, which was crimp-sealed and stored at 40oC for 10 days. A purge and trap unit was developed to extract volatile products from water in vials. The extractables were trapped in an adsorbent tube and analyzed using a GC-MS coupled with an automated thermal desorber (ATD). Mass spectra were interpreted by comparison with a NIST mass spectral library, and an internal standard method was used to quantify the extractables of interest. Several volatile compounds, such as butanal, pentanal, hexanal, heptanal, octanal, nonanal, 2,2-dimethyl propanal, 3-hexanone, 2-hexanone, and heptanone were found in ozonated water containing PP, EVA, and HDPE polymers. These compounds could cause off-taste with a low organoleptic threshold. In general, the concentrations of the migrants increased with ozone treatment. Highest concentration found was 14.1 ± 0.6 ppb for hexanal. Even at a treatment level greater than 10 times the current regulatory limits for bottled water, however, extractables migrating from those polymers were within the levels authorized by the FDA. For the PET sample, no significant peak changes were observed before or after ozonation. These results imply that off-taste in ozonated bottled water results mainly from PP caps containing EVA liners.
Session 100B, Food Packaging
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