THE EFFECTS OF SMF, EHPP AND HYDROGEN PEROXIDE ON THE DEVELOPMENT OF YEASTS

摘要

The effect of 0.5 mT Static Magnetic Fields (SMF), 50 W/kg and 9,3 GHz Extreme High Power Pulses (EHPP) and dose-dependent effect of hydrogen peroxide (H_2O_2) on leaven yeast (Sacharomyces cerevisiae, strain L-41) development was studied. It was shown that at room temperature (22°C) SMF has activation, while in warmer medium (36°C) -inactivation effect on yeast development. EHPP-treated wort has biphasic effect on yeast growth: the first 20 min. incubation has an inhibitory effect on it which was followed by about 2 hours of activation period. The higher doses of H_2O_2 (> 10~(-5)) inhibits the yeast growth, while low doses ( > 10~(-7)) has activation effect on it. It is suggested that SMF and EHPP-induced changes of H_2O_2- level in wort could serve as one of the messengers through which the modulation effect of the mentioned factors on yeast growth could be realized.