VIEW ARTICLE    DOI: 10.1094/ASBCJ-37-0077

Effect of Pressure on Physiological Aspects of Germinating Barleys and Quality of Malts. Tokuo Yoshida, Katsuhiko Yamada, Seiji Fujino, and Junichi Koumegawa, The Research Laboratories of Kirin Brewery Co., Ltd., Miyahara-Cho, Takasaki, Gumma Pref., Japan. J. Am. Soc. Brew. Chem. 37:0077, 1979.

The effect of pressure treatment of barley at steeping on the physiological aspects of germination and the quality of malts was studied. Respiratory activity of barley during steeping was examined with a polarographic sensor, and gibberellin content in barley kernels was determined by bioassay with barley endosperm. Fermentability of wort was examined. The results showed that when barley was subjected to higher pressure, respiration increment was restricted, possibly because part of the embryonic organs was destroyed by water forced into the embryo. Pressure treatment significantly suppressed development of endogenous gibberellin in barley kernels during germination. The rate of modification in the resultant malt was low, but the color of the wort derived was higher. Fermentability of the wort became lower, and premature flocculation of the yeast during fermentation occurred. The extent of the effect of pressure treatment was greatly influenced by the degree and duration of pressure, the phase of steeping at which treatment was done, and the barley variety used.

Keywords: Barley, Germination, Gibberellin, Pressure, Respiration.