Smear Ripened Cheeses

Cheeses are produced at local and industrial scales generating over 1,000 varieties of cheese in Europe. Most cheeses have a complex successional microbial flora through milk fermentation, curd maturation and storage, to cheese maturation. Microorganisms are introduced with raw materials, by deliberate inoculation and from the environment. Microorganisms are responsible for most of the changes which produce cheese, give it its organoleptic properties and contribute to its preservation, but they may include pathogens, of which Listeria monocytogenes is the most common. The activity of aminotransferase, enzymatic degradation of L-methionine and the subsequent formation of volatile sulphur compounds leads to the development of the typical flavour in smear cheese. The characteristic features of cheese evolve from complex interaction of the metabolic activities of the smear cheese flora. So it is essential to define and identify surface microflora to enable the selection of strains that generate the colour, aroma and organoleptic qualities of specific cheeses, and to screen for anti-listerial activity.