Tracing the “pedigree” of Valdeón blue cheese
Cristina G. Pedraz/DICYT The Food of Animal Origin Technology and Quality Research Group of the University of León (ULE) is working in an area with the ultimate purpose of determining the microbiological, physico-chemical, and sensory characteristics of one of the most traditionally crafted cheeses of the province of León, the blue cheese produced in the Valdeón Valley in the heart of the Picos de Europa.
Few detailed scientific studies have been carried out on this cheese and the objective of the ULE researchers was to fill this gap. In order to do so they collaborated with the cheese factory that works with the Protected Geographical Indication (Indicación Geográfica Protegida, IGP) of the Cheeses of the Picos de Europa.
As DiCYT has been told by José María Fresno, one of the researchers of the group, the ultimate aim is to get to know the special features of the Valdeón cheese that distinguish it from other cheeses produced in various European regions and thus avoid confusion with other similar products and even forgeries.
“We have divided the study of the characteristics of the Valdeón cheese into three parts; microbiological, physico-chemical, and sensory. The results of the microbiological and physico-chemical parts have been published in the Food Chemistry journal. We have studied different populations of microorganisms (lactic acid bacteria), both those that make a positive contribution to the product and those that may alter it, with the objective of characterising them and seeing how they evolve during the ripening process. In addition, we have carried out a physico-chemical study in which we have determined the chemical composition (for example of fats, proteins, or salts) and followed up the changes undergone by the lactose and mainly by the protein (proteolysis) during the ripening of the cheese, with the aim of finding out its effect on the quality of the end-product”, the researcher explains.
The third part of the project, that of the sensory properties of the product, is in the process of being published. Moreover, one of the researchers of the group is completing her doctoral thesis on the influence of the production period on the characteristics of the cheese, and on cheeses produced with raw milk and cheese produced with pasteurised milk to find out the differences.
These studies have been financed by the Regional Government of Castilla y León and by EFRD funds from the European Union.
The Food of Animal Origin Technology and Quality Research Group of the ULE has two areas of work, one concentrating on meat products and another on dairy products. The area of research into dairy products, which includes the study of the Valdeón cheese, consists of nine members, teachers and scholars mainly from the Food Hygiene and Technology Department of the Faculty of Veterinary Science and also from the Science and Technology Institute of the ULE: María Eugenia Tornadijo, José María Castro, Bernardo Prieto, Isabel Diezhandino, Patricia Combarros, Domingo Fernández, Erica Renes, Leticia González, and José María Fresno himself.
In 1997 the scientific team began to characterise handmade cheeses, essentially from Castilla y León. Many of these varieties were in decline owing to the abandonment of traditional activities in the villages. The objective was to characterise these varieties, almost all of which were produced from raw milk and consumed after a short ripening period, which led to certain food safety problems. “By means of these studies an attempt was made to revive this cheese production but with greater guarantees for the consumer”, Fresno points out.
After these initial studies the researchers have concentrated on other aspects such as the optimisation of technological processes for cheese production with the ultimate aim of improving quality; or the search for microorganisms with a technological aptitude that may have industrial applications in cheese production or that may increase the biohealthy effect of this type of product.
The researchers are also carrying out studies with autochthonous lactic bacteria of traditional cheeses to prepare pioneering cultures for the dairy industry, thus replacing commercial ferments. The group has patented some cultures and has signed an agreement with the Bioges company for their production and marketing.
Other aspects that the group is working on include the improvement of the sensory properties (such as texture, colour, aroma, and tastes) of the cheeses, and more recently the functional properties of honey in a collaboration project with the Hospital Universitario de León.
Diezhandino, I., Fernández, D., González, L., McSweeney, P. L. H., y Fresno, J. M. (2015). “Microbiological, physico-chemical and proteolytic changes in a Spanish blue cheese during ripening (Valdeón cheese)”. Food Chemistry, 168, 134-141.