Production of aglycone type isoflavonoids, Genistein and Daidzein, and p-glycosidic type isoflavonoids, Genistin and Daidzin, by the soy plant callus suspension culture was investigated in a batch system. Genistein and Daidzein concentrations increased during the exponential growth phase of the biomass. Genistin and Daidzin concentrations were not directly related with biomass production. Methyl jasmonate addition to the growth medium (0.1 kg/m(3)) was found to increase isoflavonoid biosynthesis by 5-6 times. Isoflavonoid production in the 7 days old culture increased with pulsed electric field (PEF) application at 1.6 kV, and aglycone forms were influenced to a greater extent. (C) 2010 Elsevier Ltd. All rights reserved.