Distribution and development of bacterial colonies in fermented sausages

Abstract

For fermented sausages the growth of microorganisms is essential for stable and safe products. It is important to note that the natural flora as well as added starter cultures are not evenly distributed in the interior of fermented sausages, but are immobilised in cavities or nests within the sausage matrix. A fact which must be taken into account when investigating growth kinetics and metabolism of, and interactions between, microorganisms during sausage fermentation. The distance between these nests of ripening flora varies from 100 to 5000 μm. If the properties of a sausage are changing during the ripening process in the desired direction (nitrate reduction, lactic acid production, catalase activity, etc.), then “large void areas”; of the sausage matrix between these cavities must be influenced by the bacteria growing in the nests. The latter are in keen competition. Therefore, after some time, due to accumulation of metabolic products and depletion of nutrients, bacterial growth ceases and cell divisi...