Application of Electrolyzed Water to Improve Angiotensin I-Converting Enzyme Inhibitory Activities of Fermented Soybeans Started with Bacillus Subtilis B1

Angiotensin I-converting enzyme (ACE) inhibitory activities of soybeans fermented by Bacillus subtilis B1 with pretreatment of soaking in electrolyzed oxidizing (EO) water, electrolyzed reduced (ER) water, chemically modified acidic and alkaline solutions as well as conventional tap water were investigated. Using electrolyzed water improved significantly (p 0.05) the ACE inhibitory activities of fermented soybeans as compared with using tap water. The highest ACE inhibitory activity was recorded as an IC50 value of 0.065 mg/mL in the sample, which had been pretreated by soaking in ER water prior to fermentation. The ACE inhibitory activity increased to and tended to keep at a higher level during fermentation of EO water-soaked soybeans. However, there was no evident advantage of chemically modified acidic and alkaline solutions over tap water. Results suggested that electrolyzed water possessed potent ability to improve the ACE inhibitory activity of fermented soybeans, which might be through providing an appropriate microenvironment for the hydrolytic actions of microorganism to generate ACE inhibitors. In addition, this work also suggested a potential ability of electrolyzed water to be applied into the production of functional foods.