Genetic ID Card To Determine Quality of Andalusian Goat's Cheese

24/08/06 The study of the Department of Microbiology of the UGR, under the supervision of Professor Manuel Martínez Bueno, intends to characterize the bacterial strains in the home-produced cheeses Cueva de la Magahá and Montefrieño (Granada), as well as from Aracena (Huelva). Such cheeses are representative of a traditional production process using raw milk and rennet. Its microbiological richness is higher than that of industrially-produced ones which, although they are completely fit for human consumption, lose part of their distinctive properties.

To characterize the bacterial strains, the research team has used two basic techniques: the traditional methods depending on microbial cultures and the innovative molecular methods of DNA extraction and characterization. Whereas in the first ones you have to wait for bacteria to grow, with the DNA it is possible to do a much faster and exhaustive analysis of all the micro-organisms of the product. These two techniques are complementary.

Through this joint process, the research team obtains the genetic fingertip of the cheeses, an identification of the organisms they are made of and their relation with the organoleptic features (which can be perceived by the senses) of the cheese. The process is done again in the different ripening phases to see how micro-organism populations vary according to time and scientifically establish the development process of the product. Finally, the research work has tried to determine the safety of this kind of cheeses, which is essential to commercialize them.

Safe food

To this extent, the presence of enterococci, a type of bacterium usually associated to the faecal contamination of food. This kind of bacteria can be naturally found both in human and animal intestine, but they can be beneficial, as they avoid the implementation of pathogen agents. According to the analysis carried out, although these micro-organisms often isolate themselves from traditionally-produced cheeses, their presence is not harmful to health. Furthermore, enterococci also influence positively cheese properties.

“Even in industrially-produced products we have found enterococci, and it does not mean that they are unfit. The analysed goat's cheeses are completely safe”, specifies Manuel Martínez Bueno, a microbiologist of the University of Granada. These results, together to those recently published by another research group of the UGR emphasizing the excellent nutritive properties of goat's milk, can be a recognition for a cattle sector that, in the last thirty years, have found their livestock reduced to the half.