Detail of "5287-45-6"

Reference

The light stability of beer

The light stability of beer. Maendli, Hugo; Anderegg, Paul (Versuchsstn. Schweizerischer Brauereien, Zurich, Switz.). Brau.- Getraenke-Rundsch., 102(12), 281-7 (German) 1991. CODEN: BRGRED. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) 3-Methyl-2-butene-1-thiol (I), responsible for the light off-flavor of beer, was synthesized by the reaction of 3,3-dimethylallyl bromide with thiourea or NH4 dithiocarbamate, and hydrolysis of the intermediate, without isolation, with NaOH. I was detd. in beer by closed loop striping with N, adsorption on an activated charcoal filter, extn. with EtOAc, and gas chromatog.-mass spectrometry with di-Bu disulfide as internal std. In the processing, I is completely dimerized to the disulfide, which is measured. Illumination studies were made with fluorescent and Hg vapor lamps, and daylight, with beer in white, green, brown, and brown-green glass bottles or green PVC and brown PET bottles, by measuring I formation. With sunlight, the green PVC and glass bottles gave almost equal protection, as did the brown PET and brown and brown-green glass bottles. I formation under sunlight for 4 h was 0.52 ppb in green bottles and 0.16 ppb in brown. With fluorescent and Hg vapor lamps, I formation was <0.04 ppb in PET brown bottles and 0.08 ppb in brown glass bottles after 120 h; concns. formed in green bottles were higher. 9002-86-2 and 5287-45-6 are just another two chemicals used in this study. The presence of ascorbic acid increased the formation of I slightly but significantly. .