Microbial key to taste in Reblochon cheese
Reblochon is a soft smear-ripened cheese. Cheeses ripened in this way are a dynamic ecosystem in their own right, their flora adapting to the changing physico-chemical environment as well as their microbial neighbours as the cheese matures. Despite their importance to the cheese industry, little is known about their ecology. Researchers at the Technical Institute of French Cheese investigated the surface microbial content at different stages of ripening. They used advanced methods of bioanalysis including similarity analysis from Fourier transform infrared spectroscopy (FTIR) spectra and other biomolecular tools for delineation of species discovered. The microbial inhabitants of three batches of Reblochon cheese from different farmhouses were found to be composed almost exclusively of coryneform bacteria. Their dominance was found to be independent of the stage of ripening. Another noticeably predominant species, but this time dependent on its physical environment, was Microbacterium gubberense. This microorganism was found mostly at the end of ripening because of its sensitivity to low pH. There were surprises in that another member of the same family was isolated from the cheese for the first time as far as the researchers were aware. Reblochon has a unique taste which could be described as nutty. Moreover, this lingers in the mouth after the soft middle has been savoured. The microbial diversity at the surface of this traditional cheese is responsible, in part, for the sensory properties of the food. Further research into this topic should reveal the nature and determinants of the delicate balance between different species. Furthermore, their relationship with less welcome inhabitants in cheese of this nature, for example listeria, may be further elucidated.
