STRATIFICATION AND IDENTITY OF BACTERIA ASSOCIATED WITH SPOILED, VACUUM-PACKAGED VIENNA SAUSAGES

Microbiological analysis of five packs of spoiled, vacuum-packaged, smoked vienna sausages yielded high numbers of lactic acid bacteria, whereas Enterobacteriaceae and yeasts were absent. Examination of spoiled sausages by scanning electron microscopy indicated qualitatively that bacteria predominated on the surface rather than in the core of the sausages. These observations were supported by quantitative plate counts. Sausage cores contained ca. 10(6) lactic acid bacteria per gram, whereas numbers on surfaces approached 10(8) lactic acid bacteria per gram. Exudates contained ca. 10(10) lactic acid bacteria per millilitre, and pH values of 4.3 and 4.6 were measured for exudate and sausage samples, respectively. No noticeable differences in microbial numbers between individual sausages and compound samples of four sausages in the same pack were found. The predominant isolates from plates of the highest dilutions comprised lactic acid bacteria consisting mainly of Leuconostoc (38.2%) and homofermentative Lactobacillus (55.4%) species.