First pigment fingerprints from the rind of French PDO red-smear ripened soft cheeses Epoisses, Mont d'Or and Maroilles

Red-smear ripened soft cheeses are characterised by their orange–red color which originates from the carotenoids and other pigments produced by ripening bacteria. The color of the rind of three types of cheeses of this family (Maroilles, Mont d'Or and Epoisses) with Protected Designation of Origin (PDO) was first analyzed by spectrocolorimetry in the CIE L⁎a⁎b⁎ color space. The pigments were then extracted, quantified by spectrophotometry and analyzed by HPLC. A spectrocolorimetric cartography of cheeses was established as well as the pigment fingerprints were obtained for every PDO. By these combined methods, the three PDO cheeses studied could be distinguished. Most pigments observed at the surface of these cheeses seem to be common to all the three PDO. Only the relative composition in these pigments allows to obtain different and specific fingerprints. The origin of these pigments seems essentially related to the presence of yellow bacteria, the pigments of Brevibacterium linens group are only present on Maroilles.Industrial relevanceSmear ripened soft cheeses are produced at large scale in many European countries and are characterized by a strong smell and a yellow, orange or red color. The information collected during this work provides new data concerning the coloration of cheeses. Firstly, L*a*b* and HPLC references characteristic for the surface coloration of particular cheeses are presented and secondly, data concerning bacteria strains capable of performing the pigmentation process is documented. Dairy industry professionals have now results leading to new research perspectives, both concerning the characterization of cheeses and the elaboration of bacterial microflora for ripening.