27-5 |
Plastic “off-taste” control in bottled water closure compositions |
W. E. WOOD, Cellresin Technologies, LLC, 1789 Buerkle Circle, St. Paul, MN 55110 For the bottled water market, taste is an essential quality. Any trace of organoleptic contamination from the package (i.e., bottle or sealing element) is readily detectable in the product. The organoleptic defect is often described as a “plastic” taste. The plastic off-taste can be associated with the presence of part per billion (ppb) levels of aldehydes, particularly hexanal, heptanal, octanal, nonanal and decanal, whose origin is the polyolefin and performance additive compositions used to manufacture closure liners or threaded closure shells. Disinfecting bottle water with ozone, a common practice in North America, increases the plastic off-taste contaminants. The objective is to eliminate the off-taste problem in commercial closure shells and closure liners by adding a complexing agent, cyclodextrin, to the closure compositions to reduce aldehydes and other closure migrants in bottled water treated with ozone. Two polyolefin closure compositions were tested: a closure liner comprising low density polyethylene / ethylene vinyl acetate (LDPE/EVA) and a closure shell comprising polypropylene (PP). Molded closure compositions were compounded with and without cyclodextrin materials and immersed in deionized water containing 0.8 ppm ozone inside 450-mL glass bottles, which were sealed with aluminum faced metal screw cap closures. The bottles containing the closure compositions were stored at 40oC for 7 days. At the end of the accelerated storage period, the aqueous contents were solvent extracted, concentrated and then analyzed by GC/MS. When exposed to ozone treated water, both closure compositions produced ppb and sub-ppb levels of C6 to C9 aldehydes. Closure compositions containing cyclodextrin substantially reduced the aldehydes concentration. Total C6 to C9 aliphatic aldehydes were reduced by 62% in liners and 84% in shells. Aldehyde reduction is both a function of cyclodextrin isomer (alpha, beta, gamma) and concentration. Cyclodextrin can reduce aldehydes formed by ozonolysis of closure compositions contacted by ozone treated water.
Handout (.pdf format, 439.9 kb)
Session 27, Food Packaging: General
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