Department of Food Science, University of Copenhagen, Frederiksberg C, Denmark.
J Agric Food Chem. 2012 Dec 19;60(50):12362-70. doi: 10.1021/jf303044a. Epub 2012 Dec 11.
The impacts of pasteurization of a lager beer on protein composition and the oxidative stability were studied during storage at 22 °C for 426 days in the dark. Pasteurization clearly improved the oxidative stability of beer determined by ESR spectroscopy, whereas it had a minor negative effect on the volatile profile by increasing volatile compounds that is generally associated with heat treatment and a loss of fruity ester aroma. A faster rate of radical formation in unpasteurized beer was consistent with a faster consumption of sulfite. Beer proteins in the unpasteurized beer were more degraded, most likely due to proteolytic enzyme activity of yeast remnants and more precipitation of proteins was also observed. The differences in soluble protein content and composition are suggested to result in differences in the contents of prooxidative metals as a consequence of the proteins ability to bind metals. This also contributes to the differences in oxidative stabilities of the beers.
巴氏杀菌对拉格啤酒在黑暗中于 22°C 下储存 426 天期间的蛋白质组成和氧化稳定性的影响进行了研究。巴氏杀菌显然提高了通过 ESR 光谱法测定的啤酒的氧化稳定性，而通过增加通常与热处理和果香酯香气损失相关的挥发性化合物，对挥发性特征具有较小的负面影响。未巴氏杀菌啤酒中自由基形成速度更快，这与亚硫酸盐消耗速度更快一致。未巴氏杀菌啤酒中的啤酒蛋白质降解程度更高，这很可能是由于酵母残留的蛋白水解酶活性，并且还观察到蛋白质的更多沉淀。可溶性蛋白质含量和组成的差异表明，由于蛋白质结合金属的能力，导致促氧化金属的含量存在差异。这也导致了啤酒氧化稳定性的差异。
