锌离子在啤酒酿造中的作用与控制

啤酒中锌离子来源于麦芽、大米、酿造用水、酒花。Zn^2 在啤酒酿造过程中可起到催化荆作用，与氨基酸结合形成Zn-氨基酸螯合物。在啤酒酿造过程中，可激活酶提高酶的作用；促进糖化、发酵；促进蛋白质合成及其稳定性；缓解某金属离子的毒性作用，促进挥发物质的产生和双乙酰的还原，缩短发酵时间，提高啤酒质量；但含量过量会使啤酒非生物稳定性降低，影响啤酒质量。通过对糖化过程和发酵过程的控制，可降低醪液pH值。加入少量小麦芽，加入适量ZnCl2，ZnSO4及酵母营养盐等，可实现对Zn^2 的有效控制，达到最佳酿造浓度。

Roles of Zinc Ions in Beer Brewing and Its Control

Zinc ions in beer came from malt,rice,brewing water and wort.Zn 2+ acted as catalyst in beer brewing and it combined with amino acids into Zn-aminophenol compound.In beer brewing process,zinc ions could activate enzyme and improve enzyme ef-fects,accelerate saccharification and fermentation,accelerate the composition of proteins and improve protein stability,abate the toxic effects of other metal ions,advance the production of volatile and the deoxidization of diacetyl,shorten the fermentation time ,and improve beer quality.However,excessive zinc ions content in beer would abate nonbiological stability of beer and damage beer quality.pH value of mash could be decreased through the control of fermentation and saccharification.Then addition of small amount of malt and adequate amount of ZnCl 2 ,ZnSO 4 and yeast nutritious salt etc.could effectively realize the control of Zn 2+ concentration and make the concentration suitable for beer brewing.(Tran.by YUE Yang)