This news release is available in Spanish.
"Cheeses with a quality label --for example, those with Protected Designation of Origin (PDO)-- have particular features associated with the raw materials used (Latxa sheep's milk, in the case of Idiazabal cheese) and cultural aspects and/or specific cultural practices (use of raw milk and lamb rennet in paste form) which are preserved and allow products that are organoleptically distinct to be produced," explained Ojeda, co-author of the paper Sensory quality control of cheese: going beyond the absence of defects. "What is needed, however, is a group of trained and qualified evaluators so that this method is rigorously applied and good practices are followed," added the researcher.
But today there is no practical guide for the control of cheeses with PDO, so in terms of sensory evaluation each Designation of Origin decides on its own how to meet this requirement. Mónica Ojeda pointed out that most of the certification specifications of the cheeses include an ambiguous, generic definition of the sensory characteristics which the product needs to have, but they fail to stipulate how these characteristics should be controlled. What is more, there is a widespread lack of methods and trained panels to carry out sensory quality control in a rigorous way. "All this points to the realisation that the accreditation of laboratories to apply this control has yet to be addressed," said Ojeda.
In the case of Idiazabal cheese, the Designation of Origin (DO) dates back to 1987 when the perceptible characteristics of the product began to be specified and a panel of expert tasters, responsible for evaluating the degree of compliance of the cheeses covered by this DO, gradually began to be formed. Yet the evaluation method and the criteria for awarding points were not at that time sufficiently objectivised. After 1997 the cheeses began to be evaluated at the LASEHU and the whole evaluation process was gradually standardised after the year 2000.
Eight parameters: shape, rind, texture, taste, etc.
Later, in 2005, the LASEHU obtained accreditation from the ENAC (Spanish National Accreditation Body) to apply the method, and this accreditation has been renewed in subsequent audits. The evaluation method used is basically as follows: "250 cheeses per campaign are analysed (between April and October). Eight parameters are assessed (shape, rind, paste colour, eyes, smell, texture, flavour-aroma and persistence) on a scale from 1 (zero quality) to 7 (maximum quality). The analysis is carried out in a sensory evaluation room that has eight standardised test cubicles (ISO 8589) and in conditions in which temperature and relative humidity are controlled. Seven expert evaluators participate in each session and they evaluate a maximum of eight cheeses in about one hour," explained Ojeda.
The thesis that this researcher is working on is endeavouring to compare the degree of agreement between the sensory quality of the product and the preferences and acceptation of consumers in its country of origin, and also to determine the effect of sociocultural factors and familiarisation relating to preferences and acceptation of consumers of DO cheeses in various parts of Europe. According to Ojeda, "it is necessary to differentiate between 'being familiarised' with a type of cheese and 'being knowledgeable' about it. Being familiarised means eating it on a regular basis without needing to know anything about it; by contrast, being knowledgeable about a specific cheese means being in possession of information about it in terms of origin, raw materials used, production process, sensory characteristics, etc.
The researcher pointed out that "when it comes to choosing or purchasing a specific product, studies carried out in Europe among consumers from different countries show that the familiarisation or knowledge of a consumer about a specific cheese influences his/her degree of acceptation/preference with respect to other cheeses with similar sensory characteristics but having a different origin".
Paper published (2015): Mónica Ojeda, Iñaki Etaio, Mª Pilar Fernández Gil, Marta Albisu, Jesús Salmerón, Francisco José Pérez Elortondo. 'Sensory quality control of cheese: going beyond the absence of defects'. Food Control 51, 371-380.