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The compromised acceptance threshold (CAT) indicates the intensity of a stimulus from which product acceptance is significantly altered. This new affective threshold is determined by hedonic threshold methodology (HTM). The levels of analytical performance associated with precision (repeatability, intermediate precision, and reproducibility), accuracy, and robustness of CAT results were investigated. The methodology met the pre-established criteria, being accurate in assessments carried out consecutively (repeatability), in tests separated by a certain period of time as well as with different consumer panels (intermediate precision), and in tests carried out in different facilities (reproducibility). The methodology presented suitable accuracy, though slightly conservative, which may be desirable. The methodology was also shown to be robust as it allowed the reduction of panel members from 150 to 70 consumers. In this context, the methodology-which presented reliable results as well as high precision, accuracy, and robustness-was validated. Practical applicationsThe need for showing the quality of sensory measurements is being increasingly recognized and required for the acceptance of new methodologies within the scientific community, given that unreliable analytical data may lead to dreadful decisions as well as long-lasting financial losses.Results from the present work show that the data obtained through the hedonic threshold methodology/compromised acceptance threshold methodology met all criteria of the evaluated analytical indexes. Thus, one may conclude that this methodology has suitable precision (repeatability, intermediate precision, and reproducibility), accuracy, and robustness (by reducing consumer panel size) levels and is efficient in providing reliable results. Hence, this method can be applied for the intended purpose.

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The optimized descriptive profile (ODP) is a new descriptive methodology which proposes an optimized sample evaluation by no trained assessors. To permit that assessors with a low degree of training quantitatively evaluate samples consistently, this method proposes the presentation of reference materials ("weak" and "strong") together with all set of samples at the time of evaluation. The attribute-by-attribute protocol is recommended on the ODP technique to allow for comparison among the samples and avoid fatigue, since only one attribute is evaluated at a time. Simultaneous presentation of the samples, together with the reference materials, is the "key point" of the ODP, and therefore the number of samples may be a limiting factor in this technique. The purpose of the present study is to determine if the balanced incomplete block design (BIBD), used in descriptive techniques traditionally, may be an alternative for data collection on this specific methodology, the optimized descriptive profile (ODP). The BIB design does not allow for comparison among all samples together, but only among a fraction of them. Therefore an assessment of the data quality obtained through this design is necessary to increase the applicability of the ODP. In this experiment a specific set of grape juice formulations was used, which presented variations in pulp and sugar contents. Sensory evaluation was conducted with two independent panels, where each panel evaluated the samples using the ODP protocol in a specific design. Thus, one panel evaluated the samples using the balanced complete blocks design (BCBD) and the other panel the balanced incomplete blocks design (BIBD). The data obtained by the two designs were compared in relation to analysis of variation, F-test power and regression models. Data obtained by the ODP conducted in the BIBD was very similar to that of the ODP in the BCBD. In the ANOVA, the formulations differed (p<0.05) in relation to all attributes, showing a test power (1 - β) greater than 0.95. The regression models obtained in the different designs indicated overlapping of the confidence intervals (CI 95%). Therefore, the BIBD presents itself as an alternative for data collection in the ODP without loss in quality of the results.