Sensorial evaluation, global

The description of the off-odor, identified at the beginning of the study in the global sensorial evaluation, which has been separated into several components by the gas chromatographic sniffing method can have seemingly large deviations in the descriptions of the individual components from the initial off-odor description. 

The sensory evaluation of the jams was carried out by 60 potential consumers and the attributes appraised (appearance, aroma, texture, color, flavor and global impression) judged using a structured 9 point hedonic scale (1= disliked extremely to 9= liked extremely). The experiment was applied to a balanced complete block design according to Stone and Sidel (2004), and 20 g of each treatment presented in plastic cups codified with three digit numbers. The tests were carried out in individual booths in the food sensory analysis laboratory. The results were submitted to an analysis of variance (ANOVA) and the differences between the averages compared by the test of Tukey at 5% of probability (Cochram Cox, 1992). 

In sensory and consumer science studies, one of the common basic goals is to explore how the products differ in terms of the measures collected. Usually Chi-square is calculated to evaluate differences in the consumers perception of the products. This can be first done globally, to test the independence between the rows and columns of the contingency table, and then per cell to evaluate if each category term is able to detect significant differences in the perception of the labels shown (Symoneaux et al, 2012). 

Questionnaire Seven sensory criteria are chosen to cover the main dimensions of variation within the trials, with of course a focus on the important dimensions for the project. There are four scale criteria, namely acid intensity, sweet intensity, global aroma intensity, orange intensity, and three CATAs, namely off note, fresh aroma and citrus note. Note For aroma note, CATA is often selected as it allows for an easier evaluation with untrained judges. 

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