Yeast: Difference between revisions
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Yeast is regarded as the best "antioxidant" for brewing due to its strong ability to absorb dissolved oxygen.<ref name=niecon>Nielsen H. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1973.tb03517.x The control of oxygen in beer processing.] ''J Inst Brew.'' 1973;79(2):147–154.</ref> | Yeast is regarded as the best "antioxidant" for brewing due to its strong ability to absorb dissolved oxygen.<ref name=niecon>Nielsen H. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1973.tb03517.x The control of oxygen in beer processing.] ''J Inst Brew.'' 1973;79(2):147–154.</ref> | ||
Although sufficient oxygen must be supplied to yeast to promote lipid synthesis and satisfactory fermentation, it has been demonstrated that oxygen can lower the viability of yeast, exerting its effect via superoxide or species derived from it (20). Upon exposure to oxygen, yeast responds by synthesizing SOD and catalase, enzymes that are suppressed under anaerobic conditions (20). As for all aerobic organisms, those enzymes are triggered to promote protection against radical damages. In the transition period necessary for the elaboration of these enzymes, yeast is susceptible to oxygen radicals, a problem that should be considered when designing systems for providing oxygen to yeast.<ref name=bammul>Bamforth CW, Muller RE, Walker MD. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-51-0079 Oxygen and oxygen radicals in malting and brewing: a review.] ''J Am Soc Brew Chem.'' 1993;51(3):79–88.</ref> | |||
==Preparing yeast for fermentation== | ==Preparing yeast for fermentation== | ||