VIEW ARTICLE    DOI: 10.1094/ASBCJ-43-0183

Determining Pasteurization Units From Residual Melibiase Activity in Lager Beer. Bent Stig Enevoldsen, Department of Brewing Chemistry, Carlsberg Research Center, DK-2500 Valby, Copenhagen, Denmark. J. Am. Soc. Brew. Chem. 43:0183, 1985.

A method was developed to determine the number of pasteurization units a lager beer has received from measurements of beer pH and residual melibiase (α-galactosidase) activity. A procedure for determining the melibiase activity is given. For a given pH and temperature, the heat inactivation of melibiase was shown to follow an exponential decay. Then 35 heat inactivation constants (k) were determined at seven pH values (pH 3.90-4.50) for five temperatures (60.0-64.1° C) for two lager beers. Based on either the experimental or the computed values for k at pH 4.0-4.5, a method is outlined for assessing the number of pasteurization units of a lager beer. For beer pasteurized at 60° C, it was possible to estimate up to 30-125 PU, depending on the pH of the beer. The melibiase method was judged to be accurate to ± 20%.

Keywords: Enzyme, α-Galactosidase, Heat inactivation, Lager beer, Melibiase, Pasteurization