[Research of dimetil sulfide dynamics in beer production]
2007
Lebedeva, V.E. | Dedegkaev, A.T. | Afonin, D.V | Meledina, T.V.,St.-Petersburg State Univ. of low-temperature and food processes (Russian Federation)
The content beer dimethyl sulfide (DS), giving an unpleasant smell of cooked corn, depends on a variety of barley, a place of cultivation and year of crop yield, technologies of malting, technological modes of boiling of wort with hop, duration of stay of wort in virpul, technological features of the equipment. Ten parties of the malt made from the following barley varieties of 2002 crop Scarlett, Lux, Prestige, Esterel, Ortoli, Nevada (France) and Barke (Denmark), Scarlett (grown in 2 regions of Russian Federation: Scarlett 1 and Scarlett 2) were investigated. The maintenance of DS precursors (DS-P) in all samples of malt below maximum permitted value (4 mg/kg of malt) is revealed, however their level in the malt from Scarlet (Russian Federation) exceeds the parameters for the same grade of barley from France on 20-25%. The index of thiobarbituric acids (TBA) correlates with concentration of (DS-P) The wort received from all the samples of malt, except of Scarlett 1, contains less TBA index. The content of free DS in ready beer exceeds a threshold of sensitivity (50 mkg per l) in samples from Scarlett 2 and Ваrке. The DS-P content in Nevada and Scarlett 1 was noted as above 3 mg/kg. At studying the influence of a mode of boiling with hop on the content of free DS the malt of high quality from Lux (DS-P was 2,34 mg/kg) was used. The increase in duration of boiling process led to reduction of content in a wort of free DS and to increase in TBA index. Optimal duration was 60 minutes (without additional evaporation). At fermentation of wort the DS content decreased on 20-30% that was connected with its removal with carbon dioxide. During storage of ready beer within 4 months there were no noticeable changes of DS level.
显示更多 [+] 显示较少 [-]