Protein: Difference between revisions

As described above, grain proteins are solubilized during the mash.  Much of this protein is then removed during the mash, the boil, and during fermentation. Yet, approximately one-third of the protein content is resistant to degradation and precipitation and hence passes through the processing steps, intact or somewhat modified, to the final beer.<ref name=steiner/><ref name=jin/><ref name=lund/><ref name=han>Han Y, Wang J, Li Y, Hang Y, Yin X, Li Q. [https://www.sciencedirect.com/science/article/abs/pii/S0308814615005993 Circular dichroism and infrared spectroscopic characterization of secondary structure components of protein Z during mashing and boiling processes.] ''Food Chem.'' 2015;188:201–209.</ref> A total of ~1900 unique proteins have been identified in beer.<ref name=kerr/> Almost all beer protein is derived from barley, with yeast proteins as minor constituents.<ref name=steiner/><ref name=wu/><ref name=picariello/> These proteins are well-known to influence beer characteristics such as foam, haze, color, flavor, flavor stability, and mouthfeel of beer.<ref name=steiner/><ref name=lund/><ref>Langstaff SA, Lewis MJ. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1993.tb01143.x The mouthfeel of beer—a review.] ''J Inst Brew.'' 1993;99(1):31–37.</ref> The amount of protein in beer is expected to vary enormously according to the malt used and the brewing process employed. However, the main protein components are similar in practically all beer produced.<ref name=picariello/> The "average" beer should contain somewhere in the neighborhood of 0.5–1 g/L proteins.<ref name=didier>Didier M, Bénédicte B. [https://www.sciencedirect.com/science/article/pii/B9780123738912000249 Soluble proteins of beer.] In: Preedy VR, ed. ''Beer in Health and Disease Prevention.'' Academic Press; 2009:265–271.</ref>