Exemples d'interprétation de résultats de dégustation

Abstract

<p style="text-align: justify;">De nombreux auteurs ont proposé des méthodes et des tables pour l'interprétation de résultats de dégustation, notamment ROESSLER et al. (1978) pour les tests de différence et KRAMER (1956, 1974) pour les tests de classement. Ces dernières ont été remises en question par JOANES (1985) et SMITH (1985) préconise le test de FRIEDMAN. Les méthodes d'analyses multidimensionnelles (AC.P. et A.F.C.) permettent l'interprétation de dégustations descriptives (notation ou appréciation d'un vin sur plusieurs paramètres). Des exemples sont donnés pour développer l'utilisation de ces méthodes en oenologie.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Statistics seem to be essential in a sensory valuation, not only to interpret the results but also to define the experimental protocol, to distribute samples in a balanced way, to avoid the effect of sytematic mistakes (SAUVAGEOT 81).</p><p style="text-align: justify;">A lot of authors proposed methods of calculs and tables: KRAMER (1956), KRAMER et al. (1974), ROESSLER et al. (1978), LARMOND (1969), TOMASSONE et FLANZY (1977).</p><p style="text-align: justify;">A. JOANES (1985) has just called in question again validity of KRAMER's tables (very used in œnology) it was important for us to present with few examples, some methods of interpretation of difference and preference tests.</p><p style="text-align: justify;">We especially use « duo trio and triangle tests ». The last one, more difficult, must be done with a expert panel. ROESSLER and al. (1978) proposed tables giving critical values (number of correct answers) at different probability levels.</p><p style="text-align: justify;">So we advise the FRIEDMAN's test; it's a non parametric method, with which you can know if one wine is different or not. Two wines are different if the difference between their rank sums is rank above a value determined with the NEWMAN's test.</p><p style="text-align: justify;">The descriptive tasting (appreciation of a wine with several variables: colour, arome intensity, sourness, bitterness...) give more informations.</p><p style="text-align: justify;">Two methods of multidimensional analysis are proposed to take into account the entire information:</p><p style="text-align: justify;">- The principal components analysis if the results are presented as quantitative variables,</p><p style="text-align: justify;">- The correspondance analysis if the results are presented as qualitative variables.</p><p style="text-align: justify;">Examples of interpretations are proposed to develope the use of theses methods in œnology. That's easier with the introduction of the micro-computer.</p>

Influence of Lachancea thermotolerans on cv. Emir wine fermentation

“…Wine quality is often mainly determined by sensory evaluation and less by chemical analysis (Jolly et al ., ). In the present study, wines were evaluated using ranking tests (Barillere and Benard, ; Meilgaard et al ., ), with the wine produced by pure culture fermentation of S. cerevisiae (wine B) as the control; the results are given in Table . The most preferred was wine D, made with sequential inoculation of L. thermotolerans followed by S. cerevisiae after 24 h. The next‐preferred was wine C, produced by co‐culture fermentation, although statistically significant differences were not observed between wines D and C. However, a more in‐depth sensory evaluation is needed to confirm findings in future studies.…”

“…Sensory analysis was done 6 months after completion of fermentation. The sensory evaluation was performed using a ranking test (Barillere and Benard, ; Meilgaard et al ., ), with a taste panel consisting of 13 staff of the Department of Food Engineering, under appropriate conditions. The wines were given code numbers and served in black tulip‐shaped wine glasses at 15 °C in mixed order.…”

Microbial, chemical and sensory properties of shalgams made using different production methods

“…The shalgam samples produced by various methods were evaluated by use of a descriptive and ranking test in a sensory room, at ambient temperature and in daylight. Evaluation was done by a ranking test according to Barillere and Bernard and Altug using a taste panel of 15 assessors (six women and nine men).…”

Fermentative aroma in wines from <em>Vitis vinifera</em> cv. Kalecik karasi in relation with inoculation with selected dry yeasts

“…Flavour compounds were compared by varience analysis and «Least Significant Difference» analysis (AME-RINE and ROESSLER, 1976). The detailed statistical tables were used for triangle test and ranking test was analysed by Friedman test (AMERINE and ROESS-LER, 1976;BARILLERE and BENARD, 1986).…”