Sensory Descriptors for a Taint in Water Packed in Test Pouches Made of Polyethylene Lined Aluminium

A panel of 48 assessors evaluated a taint in water, packed in test pouches made of low density polyethylene (LDPE) lined aluminium. This panel agreed upon eight descriptive attributes (in Dutch): metallic (metaal), syn thetic (synthetisch), dry (droog), rough (stroef), astringent (wrang), musty (muf), sickly (wee) and penetrating (doordringend). Fourteen assessors, selected with a standard triangle test, were asked to judge intensities for these attri butes on a visual analogue scale. Factor analysis reduced the original data- matrix to a six dimensional one losing only 6.4% of the original variance. Syn thetic and penetrating loaded high on one factor as well as rough and astringent on another one. Musty, sickly, metallic and dry loaded high on sepa rate factors.

Direct dynamic headspace analysis of the LDPE-lined test pouches gave mainly peaks of branched alkanes of 12 carbon atoms. However, dynamic head space analysis of water in contact with the LDPE layer of the test pouches showed no alkanes but (C₄ - C₁₁) aldehydes and ketones.