Inhibition of Undesirable Gas Production in Tofu

Abstract

ABSTRACTOf 100 gas‐producing bacterial isolates, 65% were Gram‐negative. Bacterial growth and gas production in commercial tofu was accompanied by acidification, and pH decreases as low as 5.2. Coliform bacteria constituted 15% of the total bacterial flora. Sporeformers and yeast counts remained < 103 CFU/mL. Pasteurization was effective in lowering the bacterial counts, and retarded gas production. The addition of lactic acid (reducing pH to 5.5) or lactic acid bacteria (2 × 107 CFU/g) to tofu helped reduce gas production by about 50%. Addition of both lactic acid and Lactobacillus plantarum stopped gas production in contaminated tofu.