M. I.  Franco*, M. M. Pintado, A. M. Gomes, M. J. Monteiro, A. C. Silva-Ferreira, F. K. Tavaria, F. X. Malcata

Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Portugal

Flavour perception is one of the foremost criteria of organoleptic quality, classically used by a cheese grader in product evaluation, and by a cheese consumer in defining acceptance and preference. Hence, the dairy industry has recognized for a long time that sensory quality – and flavour in particular, is one of the most crucial aspects of sales and marketing.

Descriptive sensory analysis is performed so as to objectively determine the flavour profile of a food – and can be employed to advantage, together with instrumental analysis, to ascertain a more complete picture of flavour. A core group of volatile compounds plays indeed a critical role on the overall flavour – this is especially the case of ripened cheeses, e.g. Serra da Estrela and Serpa: both possess a DOP status, and are manufactured from raw ovine milk and coagulated with enzymes extracted from the plant Cynara cardunculus.

By selecting appropriate sensory and instrumental techniques, a rather complete portrait of flavour can be achieved. Therefore, the overall goal of this research effort was to pinpoint and compare sensory attributes, that may be responsible for key flavours describing Serra da Estrela and Serpa Cheeses by the end of ripening, using specific sensory language developed by descriptive analysis.

Sensory analysis was duly implemented, and the main descriptors for Serra da Estrela Cheese were vomit, acidified milk, ewe’s milk/stable/barny, sour milk, buttery, sulphurous, herbaceous, bakers yeast, olive oil/olive and cooked milk – sorted by descending order of intensity; and for Serpa cheese, they were olive oil/olive, bakery yeast, acidified milk, sour milk, vomit, baby vomit, spices, stable/barny/ewe´s milk, metallic, amoniacal, buttery, putrid/sulphur compounds and soapy, respectively. Sensory studies were then correlated with GC-MS analysis, in attempts to confirm the impact of each compound identified upon sensory perception of each of such cheeses.