Method for culturing lactic acid bacterium and method for producing fermented milk

摘要

A method for culturing lactic acid bacteria includes (a) adding a proteolytic enzyme to an aqueous whey solution containing whey and water to thereby prepare a culture solution containing whey degraded by the proteolytic enzyme; (b) inoculating the culture solution with Lactobacillus gasseri which is a bacteriocin-producing lactic acid bacteria; and (c) maintaining the culture solution inoculated with the bacteriocin-producing lactic acid bacteria at a pH of not lower than 5.2 and not higher than 5.8 to provide cultured lactic acid bacteria. After the completion of culturing, the culture solution is centrifuged to separate a concentrated cell suspension containing the lactic acid bacterium in a concentrated form. The concentrated cell suspension has extremely high antibacterial activity, several tens of thousands AU, and is usable as a food preservative. Yogurt is produced by fermenting a yogurt mix to which 0.01% to 0.1% by weight of the concentrated cell suspension is added.