Over de vroeg beginnende gasvorming in kaas

The early production of gas in cheese, called 'blowing' was caused chiefly by some coli-aerogenes bacteria of the aerogenes-cloacae type and intermediate types. These bacteria produced gas in a combined fermentation-curdling test both on milk and on cheese; they were called blowing-positive strains.
A second group of coli-aerogenes bacteria, although forming acid and gas from lactose in a synthetic lactose medium, did not produce gas in the combined fermentation-curdling test. This was apparently due to the presence of citric acid in the combined test since this acid prevented blowing-negative coliaerogenes strains producing gas from lactose; the citric acid was reduced to succinic acid. As a result these blowing-negative types decomposed the sugar present in the medium without forming gas. Excess of citric acid, however, may be fermented with production of gas. Citric acid always increased gas production by blowing-positive strains through its fermentation. Blowing caused by blowing-positive strains decreased when negative strains were also present.

It was found that KN0 3 , KNO 2 , and KClO 3 , prevented gas production from lactose by blowing-positive strains. These compounds seemed to be reduced, thus inhibiting gas production from lactose, while intermediate products occurred which prevented the development of the coli-aerogenes bacteria. KClO 3 appeared to be the most efficient inhibitor. Under practical conditions addition of 1 g per 100 litres milk may be sufficient. Lactic acid fermentation was not influenced by adding this amount of KClO 3 .