Thermal inactivation behavior of enzymes in fresh sake during pasturization

Abstract

Yahatanishi -ku, Kitakyushu 807-5886)Thermal inactivation behaviors of a-glucosidase, glucoamylase, a-amylase and acid carboxypeptidase in fresh sake were investigated. Fresh sake was heated at 40C-65C for 2 min-30 min. In addition, the effects of alcohol and sugar concentration on the inactivation of enzymes were investigated by using synthetic fresh sake. All enzymes were completely inactivated by heating at 65C for 2 min. a-

Inactivation of Enzymes in Fresh Sake Using a Continuous Flow System for High-Pressure Carbonation

“…We have reported that the Z values of AGA, GA, AA, and ACP in fresh sake subjected to heat treatment were 10, 8, 8 and 8 C respectively. 20) From comparison of the Z values observed in the two inactivation treatments, it is found that the Z values of AGA, GA, and AA subjected to carbonation treatment were almost equal to those in heat treatment. These results indicate that there was no difference in temperature-dependency between highpressure carbonation treatment and heat treatment on inactivation of AGA, GA, or AA.…”

“…This tendency corresponded to that by heat treatment. 20) The residual activity of AGA at 45 and 50 C decreased to 15 and 11% at residence times of 22 and 7 min respectively. On the other hand, no activity of AA at 45…”

“…These phenomena were also observed in those of AGA, GA, and ACP by heat treatment. 20) Chen et al 21) reported that inactivation of multiple isozymes which were different in thermal stability did not follow a conventional 1st-order kinetic model. In addition, it has been shown that multiple GAs in koji had different resistances to thermal inactivation.…”

“…The D values of AGA, GA, and ACP were 29, 6, and 5 min respectively at 45 C. The D value, extrapolated from the Z value, of AA was 2 min at 45 C. We have reported the D values for the inactivation of these enzymes in fresh sake subjected to heat treatment. 20) For heat treatment, the D values of AGA, GA, AA, and ACP were 135, 66, 94, and 265 min respectively at 45…”

“…We have also reported that ethanol promoted the inactivation of AGA, GA, AA, and ACP and that glucose depressed the inactivation of them, except for ACP, during heat treatment. 20) Hence, the effects of ethanol and sugar concentrations in fresh sake on the inactivation of AGA, GA, AA, and ACP in the highpressure carbonation treatment were investigated. The results for ethanol and sugar are shown in Figs.…”