Sensory quality control of cheese: Going beyond the absence of defects

- A sensory method was modified to improve the sensory quality control in a PDO cheese.
- The new method includes non-defective characteristics as quality determining factors.
- Sensory references and decision trees were developed to objectivize the scoring.
- The new method led to a broader use of the scale and increased the score dispersion.
- The new method improved the sensory description and the discrimination among samples.

There is a generalized lack of specific methods in the quality control of sensory characteristics of Protected Designation of Origin (PDO) and, in many cases, there is also a lack of sensory panels sufficiently trained and monitored. In this sense, reported experiences about how to develop procedures for sensory quality control of PDO products are very scarce.The present work describes the modification of a former sensory quality control method applied to PDO Idiazabal cheese which was included in the scope of an accredited sensory laboratory. The former method was mainly oriented to the identification of defects in the product, whereas the new method, in addition to this, provides an exhaustive description of the non-defective sensory characteristics of each sample. In the new method, sensory characteristics (both positive and negative) are identified and classified for each of the parameters considered (shape, rind, paste color, eyes, odor, texture, flavor and persistence). Quantitative sensory references for the different sensory characteristics were developed.Moreover, this work compares the results of applying both methods. Results confirmed that new method enables a more detailed description of PDO Idiazabal cheese. Also, the inclusion of the identification of positive characteristics led to a broader use of the scale, contributing to a better sensory quality differentiation among samples without defects, although increasing the score dispersion to a certain extent.The experience described in the present work could be very useful for other laboratories and certification bodies that deal with sensory quality control of PDO products, particularly cheeses.