EVALUATION OF ASSESSOR ABILITY BY SENSORY INVESTIGATION OF FRUIT JUICES AND NECTARS

The earlier elaborated and accepted sensory ability testing was proved to be useful for controlling and qualifying the assessing activity of panellists. The repeating ability expresses the agreement of scores within a short time interval. For its determination a certain number of samples are evaluated twice (or more) within one sample series. The repeating ability was calculated as the average difference of repeated scores. The evaluation accuracy of an assessor compares his decisions to the average of the whole panel. It is calculated as an average difference between his scores and the mean scores of the whole panel. Scoring deviation expresses how inclined an assessor is to give a higher score for samples of better quality or a lower score for those of lesser quality, in other words, whether his scores vary in a narrow, "medium" or a broader score range. The reference base is the deviation of the score given by the panel. Scoring deviation is the ratio of standard deviation of individual assessors and the square root of the average variance of panel members. These indices worked out and adapted to experimental data are discussed, of which especially the repeating ability and scoring deviation is interrelated. The application and calculation of such ability indices are necessary to follow with attention the activity of assessors, to consider them for the selection of panel members and in the development of their sensory memories. Unacceptable repeating ability, biassed evaluation accuracy (too rigorous or too mild) or high and low scoring deviation can lead to disqualification. The regular (possibly computer-aided) ability testing may give direct information to panel members to judge, correct and develop their own sensory abilities.