ANTIBACTERIAL ACTIVITY OF CABBAGE JUICE AGAINST LACTIC-ACID BACTERIA

Fresh juice of Cecile cultivar cabbage (Brassica oleracea) was inhibitory to the growth of four species (including seven strains) of lactic acid bacteria. Inhibition was eliminated when the cabbage was heated (steamed 10 min) before juice extraction. When Leuconostoc mesenteroides C33 was tested in juices of three other cultivars of cabbage, growth inhibition was invariably noted in fresh juices, but was variable in heated juices. Fresh cabbage juice (CJ) adjusted to higher initial pH (6.5-7.5) showed greater antibacterial activities than at pH 5.0 to 6.0. When pH 4.0 precipitate from fresh CJ was added to noninhibitory CJ (cabbage heated before extraction), antibacterial activity was restored. A heat-labile and pH-dependent factor seemed responsible for activating a precursor into an inhibitory compound.