The present invention elucidates a microbe which causes the occurrence an off-odour and an off-taste in acidic milk beverages having a pH of at least 3.5, and addresses the problem of providing a means for inhibiting growth of this microbe, without losing the flavour of the original beverage. According to the present invention, provided are: a growth inhibitor for bacteria belonging to genus Propionibacterium, said inhibitor including, as an active ingredient, diglycerol myristate ester and/or a salt thereof and an acidic milky beverage which has a pH of at least 3.5, and which includes said growth inhibitor for bacteria belonging to genus Propionibacterium.
