COMPARISON OF DISCRIMINATION ABILITY BETWEEN A PANEL OF BLIND ASSESSORS AND A PANEL OF SIGHTED ASSESSORS

The objective of this work was to compare a panel of blind assessors with one of sighted assessors in the discrimination of food products. Each panel had 20 screened and trained assessors. Five commercial food products were used: crackers, liver paste, powdered orange juice mix, Reggiano cheese and yogurt. Slight flavor and/or texture modifications were introduced for adequate discrimination difficulty. Each pair of products was tested by both panels using the triangle test and a scaled difference from control test. Numbers of correct answers for the triangle test were similar for both panels. There were minor differences between the panels in the difference from control test, due to the sighted panel having more training in the use of the scale. Overall the panels of trained blind and sighted assessors were equivalent in their performance.     

PERCEPTION OF TASTE MIXTURES BY EXPERIENCED AND NOVICE ASSESSORS1

The total intensity, sweetness, and acidity of sucrose/citric acid mixtures were judged by two types of taste panel: experienced assessors, most of whom had had many years of experience in sensory evaluation; and novice assessors, none of whom had previously taken part in a taste experiment. In other respects the experimental conditions remained almost constant. There was good correspondence between the two panels, particularly for judgments of total intensity, indicating that novice and experienced assessors evaluate taste mixtures in the same way. However, there was also an indication that experience on sensory panels may attenuate taste suppression, the suppression of acidity by sweetness being less pronounced for the experienced panel than for the novice panel. The implications for mixture perception are noted.     

COMPARISON OF SENSORY PROFILES DONE BY TRAINED AND UNTRAINED JURIES: METHODOLOGY AND RESULTS

We compare the sensory profiles of six dark chocolates done by two types of juries: some trained juries and an untrained jury. Six laboratories, each one made up of 10 to 15 judges, are regarded as trained juries since the assessors were well trained before the evaluation of the products. The second type of jury is composed of only one panel of 29 untrained assessors and this jury is named the untrained jury. Fourteen attributes were evaluated and analyses of variance have been carried out by attribute to compare the sensory profiles of the six chocolates done by the trained juries and by the untrained jury. These analyses of variance show that the two types of juries give similar sensory profiles and that the few differences are mainly due to different ways of using the scale.     

MULTIVARIATE ANALYSIS OF CONVENTIONAL PROFILING DATA: A COMPARISON OF A BRITISH AND A NORWEGIAN TRAINED PANEL

Many studies have shown that conventional profiling provides reproducible and meaningful results. However, comparison of the technique as used in different countries appears to be nonexistent. In addition, data analysis is often approached differently, and this aspect is also addressed. This paper describes a study to compare the results obtained from profiling milk chocolate samples, using trained panels in Britain and Norway. Data were analyzed using principal component analysis, generalized Procrustes analysis and partial least squares regression. Results indicate that the underlying perceptual structure of the sample spaces obtained from both panels were similar, however, the emphasis on the underlying sensory dimensions differed. Moreover, it was possible to calibrate the two profiles, which has implications for marketing products for export, as well as providing a potential tool for panel monitoring and calibration across cultures.     

EXPERTS VERSUS CONSUMERS: A CRITIQUE

In a recent paper Moskowitz (1996) refuted the notion that consumers are incapable of validly rating the sensory aspects of products. An analysis of this paper reveals that references are not presented to support his introduction, there is lack of experimental detail, parameters to compare panels were questionable, the degree of expertise of the expert panel is put to doubt and the model proposed to relate data between panels was not compared to existing models.