3.2. Microbiological shelf-life evaluation
The number of colonies of mesophilic bacteria from the first to the
twentieth storage days did not change (Fig. 2) for all treatments. However,
for the fortieth day to final storage period differences among treatments
were observed. US presented similar effect to CT, but WUS
showed a significant increase of these bacteria and indicate a positive effect
of ultrasound on pasteurization. Therefore, the comparison of US
with WUS showed that at the same time and temperature of treatment
different results were obtained during storage with an extended shelf
life for sausages treated with ultrasound. The growth of lactic acid
bacteria was not observed up to tenth day of storage for all treatments.