[Survey of pH and water activity in acidified bottled vegetables and meats (home processed) in relation to the potential growth of Clostridium botulinum].

The water activity (aw) and pH of acidified (vinegar) bottled vegetables and meat with vegetables--mostly home-canned--was examined in relation to the potential growth of Clostridium botulinum. Most products (vegetables or meat with vegetables) had water activity above the "per se" inhibitory limit (aw < 0.95) for growth of C. botulinum. Regarding pH, 96% of canned vegetables had a pH lower than 4.6, but 81% of the canned meat with vegetables had a pH above 4.6. This was attributed to the well known buffer effect of food proteins, which makes it difficult to lower food pH during acidification with vinegar. It is concluded that most bottled meat with vegetables constitute a potential hazard since these foods are marketed at room temperature, and botulism toxin may be produced if spores are present.