Abstract: An object of the invention is to provide a bacterial growth inhibitor or bacteriostatic agent against thermo-resistant and acid-resistant bacteria (TAB: thermo acidophillic bacilli), such as bacteria belonging to the genus Alicyclobacillus, in particular, guaiacol-producible Alicyclobacillus acidoterrestris, Alicyclobacillus acidiphilus, and Alicyclobacillus herbarium, the bacterial growth inhibitor or bacteriostatic agent being derived from naturally occurring substances and facile in procurement, preparation, and handling. The invention provides a bacterial growth inhibitor or bacteriostatic agent against bacteria belonging to the genus Alicyclobacillus, which contains acerola fruit juice as an active ingredient.