"The sensory properties of beer are altered during storage and aging, as a result of various chemical, physical, and sensory transformations which can affect beer quality (Guido and others 2003; Vanderhaegen and others 2006). Oxygen plays an important role in aging reactions causing a rapid deterioration of beer flavor (Vanderhaegen and others 2006). Oxygen reacts with ferrous iron (Fe2+), through the Fenton and the Haber–Weiss reactions (Figure 5), leading to the production of ROS, such as hydroxyl radicals. Formed radicals are very reactive with ethanol, the second most abundant component in beer, leading to the formation of off-flavors and consequent beer deterioration (Andersen and Skibsted 1998; Andersen and others 2000; Vanderhaegen and others 2006). Generally, the sensory profile of beer is affected by the reaction of ROS (O2 −, HOO, H2O2, and HO) with organic molecules in beer, such as polyphenols, isohumulones and alcohols (Vanderhaegen and others 2006)."
ROS = Reactive Oxidizing SpeciesStatistics: Posted by ParanoidAndroid — Thu Aug 25, 2016 9:20 am
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