Influence of heat shock-treated cells on the production of glycerol and other metabolites in alcoholic fermentation

Flavor impacts of glycerol in the processing of yeast fermented beverages: a review

“…No consistent changes on ethanol and acceptable level of variations on organic acids were found after heat shock treatments (Berlot and Berovič 2011;Berovič et al 2007;Omori et al 1996;Petropoulos et al 2010). While the yields of isoamyl acetate and the fatty acid ethyl esters were significant increase in the heat shock mutants overproducing glycerol (Omori et al 1997).…”

“…Except for the impact on glycerol biosynthesis, heat shock treatment caused a transient delay in growth but followed by more biomass production and even complete sugar consumption after cell recovery (Berlot and Berovič 2011;Berovič et al 2007;Kajiwara et al 2000;Petropoulos et al 2010). No consistent changes on ethanol and acceptable level of variations on organic acids were found after heat shock treatments (Berlot and Berovič 2011;Berovič et al 2007;Omori et al 1996;Petropoulos et al 2010).…”

“…Hence, heat shock was claimed as an effective treatment for increasing glycerol without negative impacts on beverage flavors (Berlot and Berovič 2011;Omori et al 1996). Further improvement can be made by carefully choosing the proper strains since the heat shock response is also strongly strain-dependent (Omori et al 1996;Petropoulos et al 2010). The heat shock temperature, duration and interval should also be optimized.…”

“…For the impacts of agitation, two controversy results have been obtained on glycerol yield (Bjorkqvist et al 1997;Gardner et al 1993;Petropoulos et al 2010;Radler and Schütz 1982;Remize et al 2000). Glycerol is dominantly formed under anaerobic conditions to consume the excessive NADH during yeast alcoholic fermentation.…”

“…The yields of esters and higher alcohols were slightly decreased or remained unchanged. Even no negative sensory effects was claimed for wine quality, the prolonged fermentation time and poor social acceptance still hinder the application of those genetically modified yeasts in beverage industry (Piddocke et al 2009;Verbelen et al 2009), wine ( ArroyoLópez et al 2010;Berlot and Berovič 2011;Berovič et al 2007;Csutorás et al 2014;Du et al 2011;Erasmus et al 2004;Kukec et al 2003;Orlic et al 2010;Petropoulos et al 2010;Remize et al 2000;Yalçιn and Özbaş 2008) and rice wine (Chen and Xu 2010) fermentation conditions. Some of the results are estimated from the published figures if not provided directly (Cambon et al 2006;Eglinton et al 2002;Ehsani et al 2009;Varela et al 2012).…”