Loureiro, João Avelar Maia de, 1901-19492022-01-192022-01-192009Epidemiology & Infection, Volume 43, Issue 3, September 1943, pp. 217 - 2180950-2688http://hdl.handle.net/10451/50894Copyright © Cambridge University Press 1943We have investigated, with the most satisfactory results, the possibility of using sulphur dioxide (Williams, Waterman, Keresztezy & Buchman, 1935) for the selective destruction of thiamin in foodstuffs. The S02, which decomposes the thiamin molecule into its pyrimidine and thiazole moities, is a much milder and more specific agent than the autoclave, and its action upon the nutritional properties of foodstuffs appears to be strictly limited to this scission. In consequence, the dietary percentage of sulphite yeast (supplemented with thiamin) required for optimal growth is no greater than the percentage of fresh yeast. Two (Chase & Shermann, 1931) or three times (Coward, 1939) as much autoclaved yeast must be used.engjournal article10.1017/S00221724000128571469-4409