Abstract (EN):
The Port Wine Institute (IVP) is responsible for supervising and certifying wines bearing the Porto denomination of origin. Amongst other functions, IVP controls the quality of the wines through analytic and organoleptic inspections carried out by its technical services. IVP intends to certificate the tasting panel (TP) ¿ the Institute division in charge of the sensory evaluation of the wines ¿ by an independent third-party assessment body. Based on the evaluation of the sensory parameters aroma, taste, body, and age, each panellist judges the agreement between the wine samples submitted to the IVP and the commercial name they are applying for. The decision is a binary variable that can only take the values of ¿zero¿ (the wine is rejected) or ¿one¿ ¿(the wine is accepted). A logistic regression is used in order to model the decision process of each panellist. The stability of the decision process is monitored over time using p control charts, which parameters are derived from the logistic regression classification tables. The reproducibility of the panellists perceptions are assessed replicating the tasting procedures. A reliability index that evaluates simultaneously the panellist capacity for reproducing his perceptions and the degree of adoption a ¿defensive¿ strategy was developed (the ¿defensive¿ strategy can be defined by the tendency of rating equally all the samples). The final approval or rejection of a wine sample depends on the weighted average of the decision values (0 or 1) assigned by all the panellists. The weights used are proportional to the referred index.
Language:
Portuguese
Type (Professor's evaluation):
Scientific