Yeast: Difference between revisions
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The beer filtration process reduces the contents of antioxidant phenolic compounds and melanoidins and the AOX of wort. During the cooling stage, the spontaneous adsorption of phenolic compounds and melanoidins on wort dregs and the polymerization and precipitation of catechins and epicatechins lead to the decrease of TPC in beer (Ruiz- Ruiz, Del Carmen Esapadas Aldana, Cruz, & Segura-Campos, 2020). With the increase of diatomite consumption, a large concentration of iron ions is introduced, which decreases the DPPH scavenging rate, because transition ions such as iron and copper play an important cat alytic role in the Fenton reaction, producing hydroxyl free radicals with high activity and reducing the oxidation resistance of beer (Jurková et al., 2012; Pascoe, Ames, & Chandra, 2003). The addition of tannins has an obvious effect on the rate of scavenging of DPPH free radicals, indicating that the addition of tannins will help to chelate iron ions and reduce the effect of iron ions in diatomite on beer. The reducing power of beer can be improved by maintaining pH within the range 4.3–4.4 (Han, 2016). After cooling and filtration, 6% of selenium is lost from the level in raw materials, and the total loss of selenium over the whole process of beer fermentation is 94% (Rodrigo et al., 2015). It can be seen that the percentage selenium loss is quite high, which deserves attention.<ref name=yangao/> | The beer filtration process reduces the contents of antioxidant phenolic compounds and melanoidins and the AOX of wort. During the cooling stage, the spontaneous adsorption of phenolic compounds and melanoidins on wort dregs and the polymerization and precipitation of catechins and epicatechins lead to the decrease of TPC in beer (Ruiz- Ruiz, Del Carmen Esapadas Aldana, Cruz, & Segura-Campos, 2020). With the increase of diatomite consumption, a large concentration of iron ions is introduced, which decreases the DPPH scavenging rate, because transition ions such as iron and copper play an important cat alytic role in the Fenton reaction, producing hydroxyl free radicals with high activity and reducing the oxidation resistance of beer (Jurková et al., 2012; Pascoe, Ames, & Chandra, 2003). The addition of tannins has an obvious effect on the rate of scavenging of DPPH free radicals, indicating that the addition of tannins will help to chelate iron ions and reduce the effect of iron ions in diatomite on beer. The reducing power of beer can be improved by maintaining pH within the range 4.3–4.4 (Han, 2016). After cooling and filtration, 6% of selenium is lost from the level in raw materials, and the total loss of selenium over the whole process of beer fermentation is 94% (Rodrigo et al., 2015). It can be seen that the percentage selenium loss is quite high, which deserves attention.<ref name=yangao/> | ||
SafaleTM S-04 is a maltotriose negative yeast, thus sugars remain into the beer contributing to sweet character to aroma and taste.<ref name=ligdef>Liguori L, De Francesco G, Orilio P, Perretti G, Albanese D. [https://link.springer.com/article/10.1007/s13197-020-04740-8 Influence of malt composition on the quality of a top fermented beer.] ''J Food Sci Technol.'' 2021;58:2295–2303.</ref> | |||
==Preparing yeast for fermentation== | ==Preparing yeast for fermentation== | ||