Effect of protease treatment during mashing on protein-derived thiol content and flavor stability of beer during storage

TY - JOUR

T1 - Effect of protease treatment during mashing on protein-derived thiol content and flavor stability of beer during storage

AU - Lametsch, Marianne Lund

AU - Petersen, Mikael Agerlin

AU - Andersen, Mogens Larsen

AU - Lunde, Christina

PY - 2015

Y1 - 2015

N2 - The ability of a protease added during mashing in a pilot-scale brew to release protein-derived thiols as antioxidants and thereby improve flavor stability during storage was investigated. The protease treatment resulted in increased protein-derived thiol concentrations in fresh beer produced at a pilot scale compared with a control beer without protease treatment, and electron spin resonance lag phase analysis also demonstrated improved oxidative stability of the protease-treated beer. However, the protease treatment also resulted in high sulfite levels and, therefore, it was not possible to conclude that the improvement in oxidative stability was solely a direct effect of increased levels of protein-derived thiol concentrations. The development of papery character and volatile linear aldehydes was inhibited when the protease-treated beer was stored at 35°C but the protease treatment also resulted in increased concentrations of free amino acids in beer, resulting in a more fruity aged or vinous character of the beer during storage due to increased formation of Maillard reaction products. Thiols were found to be irreversibly oxidized during storage, which indicates that thiols cannot be regenerated during storage; and, if thiols are to act as antioxidants in beer, increased concentrations must be present in the fresh beer.

AB - The ability of a protease added during mashing in a pilot-scale brew to release protein-derived thiols as antioxidants and thereby improve flavor stability during storage was investigated. The protease treatment resulted in increased protein-derived thiol concentrations in fresh beer produced at a pilot scale compared with a control beer without protease treatment, and electron spin resonance lag phase analysis also demonstrated improved oxidative stability of the protease-treated beer. However, the protease treatment also resulted in high sulfite levels and, therefore, it was not possible to conclude that the improvement in oxidative stability was solely a direct effect of increased levels of protein-derived thiol concentrations. The development of papery character and volatile linear aldehydes was inhibited when the protease-treated beer was stored at 35°C but the protease treatment also resulted in increased concentrations of free amino acids in beer, resulting in a more fruity aged or vinous character of the beer during storage due to increased formation of Maillard reaction products. Thiols were found to be irreversibly oxidized during storage, which indicates that thiols cannot be regenerated during storage; and, if thiols are to act as antioxidants in beer, increased concentrations must be present in the fresh beer.

U2 - 10.1094/ASBCJ-2015-0602-01

DO - 10.1094/ASBCJ-2015-0602-01

M3 - Journal article

SN - 0361-0470

VL - 73

SP - 287

EP - 295

JO - Journal of the American Society of Brewing Chemists

JF - Journal of the American Society of Brewing Chemists

IS - 3

ER -