POWER AND SENSITIVITY OF THE SAME-DIFFERENT TEST: COMPARISON WITH TRIANGLE AND DUO-TRIO METHODS

Unveiling the Aromas and Sensory Evaluation of Hakko Sobacha: A New Functional Non-Dairy Probiotic Fermented Drink

At the dawn of a food transition encouraging the consumption of healthy and sustainable non-dairy probiotic products, the development of a fermented functional drink based on Sobacha is considered. Sobacha is an infusion of roasted buckwheat seeds widely consumed in Asian countries for its health benefits. As fermentation improves the nutritional and organoleptic status of grains, the mixed fermentation process involved in the development of kombucha beverages (fermented sweet tea) is conducted by inoculating a symbiotic culture of bacteria and yeasts into the transposable matrix (Sobacha instead of tea). Sobacha, a healthy pseudo-cereal matrix with promising aromas, could be fermented to potentially develop an innovative drink, named "Hakko Sobacha". This neologism would reveal the fermented character of the infusion, Hakko meaning fermented in Japanese. Considering the beverage characterization, the kinetics of the volatile organic compound syntheses were determined using stir-bar sorptive extraction followed by gas chromatography coupled to mass spectrometry analysis. Odor-active compounds were theoretically calculated to estimate the flavor composition. Finally, sensory analyses highlighted the appreciation and preferences of the consumer towards the beverages. The fermentative yield differences observed between the two buckwheat concentration modalities tested seemed to be correlated with the sugar and nutrient levels available from the starch (buckwheat) matrix. Having characterized Hakko Sobacha, this study proposed the possibility of developing new beverages by monitoring the fermentative process. This should enable improved control and enhancement of their sensorial properties, which could in turn lead to greater customer acceptability.

Physicochemical, antioxidant and sensory properties of Mango Sorbet containing L-theanine as a potential functional food product

The non-proteinous amino acid L-theanine (L-THE) is associated with a range of health benefits including improvements in immune function, cardiovascular outcomes and cognition. The aims of this study were to develop a food product (mango sorbet; ms-L-THE) containing physiologically relevant doses of L-THE (0.2/100 g w/w) and determine its antioxidant, physicochemical and sensory properties in comparison to a mango sorbet without L-THE (ms). Total phenolic and flavanol content, and antioxidant analysis (DPPH, FRAP and ABTS) were determined spectrophotometrically. Both products were also evaluated for acceptability and likeability in healthy participants using the 9-point hedonic scale. Any differences that could be caused by the addition of L-THE were examined using the triangle test. Results indicated no significant differences between ms-L-THE and ms in taste of the products (p > 0.05), and the ms-L-THE was well received and accepted as a potential commercial product. Findings of the DPPH assay indicated significant difference between the two products (p < 0.05). In conclusion, we have successfully created a mango sorbet that contains a potentially physiologically relevant concentration of L-THE with antioxidant properties that could be used as a novel method of L-THE delivery to clinical and healthy populations.

Comparing Friedman versus Mack-Skillings data analyses on duplicated rank data: a case of visual color intensity

BACKGROUND

In duplicated ranking tests, panelists either rank duplicates separately (2SS) or jointly in a single session (1SS). This study compared data analyses of duplicated yellow color intensity rank data using Friedman versus Mack-Skillings (M-S) tests. Panelists (n = 75) ranked an orange juice set twice - a similar-samples set (100%, 95% versus 90%); samples other than the 100% juice were prepared by dilution with water. Rank sum data were obtained from (a) intermediate ranks from jointly re-ranked scores of 2SS for each panelist, and (b) joint rank data of all panelists from the two replications in 1SS. Both (a) and (b) were analyzed using the M-S test. The median rank data (c) for each panelist from two replications were analyzed using the Friedman test.

RESULTS

Comparing M-S with the Friedman tests, the former generally produced higher test statistics and lower P-values than the latter. However, when considering the pattern of post hoc pairwise significant differences, both tests yielded similar conclusions.

CONCLUSION

This study demonstrated that, in a duplicated ranking test with three samples that were very similar in color, separating the two replications into two complete individual ranking tests or serving sessions (2SS) may prevent sensitivity loss due to fatigue that is otherwise experienced when evaluating all samples together in a single session (1SS). We expected to find the M-S test to be more sensitive than the Friedman test; however, this hypothesis was not supported by the post hoc (Tukey's honest significant difference (HSD)) multiple comparison test results under the specific test conditions in this study. © 2019 Society of Chemical Industry.

Beverage Complexity Yields Unpredicted Power Results for Seven Discrimination Test Methods

The power of discrimination tests is crucial in determining sample size and resources needed for testing. Although research has been conducted on the power analysis of several discrimination testing methods, much of the previous research has focused on basic taste solutions, which may not be directly applicable to food and beverage systems. The objective of the current study was to compare the power of seven discrimination tests: Panelist-Articulated-2-Alternative Forced Choice (PA-2-AFC), triangle, triangle with partial presentation, duo-trio, duo-trio with partial presentation, 4-category rating methods for R-index measure, and same-different pairwise comparison for R-index measure using commercial-type beverage products. Sixty-one prescreened panelists participated in the study. Six product comparisons were performed using tea, tomato juice (three comparisons), citrus-flavored carbonated soda, and cola-flavored carbonated soda. The tests were randomized over two testing sessions for each product comparison. Triangle testing methodologies were found to be overall the most powerful methods across product categories. The PA-2-AFC method was found to be the least powerful across all products. Thurstonian modeling predicts that the PA-2-AFC method would be the most powerful method contrary to the findings of the current study. The products tested were complex in both basic formulations and in changes made between control and variant samples. Complexity of the products may have influenced the discriminability by the panelists using different discrimination tests. Further research should be conducted to characterize the specific influence of sample complexity on the power of discrimination methodology. PRACTICAL APPLICATION: There are several discrimination testing methods that can be selected when determining whether two products are significantly different. A method with high statistical power can allow researchers to save time and resources when addressing this question. The current research compares seven discrimination test methods in order to determine which method results in the highest power for several common commercial-type beverage products. The results from this study demonstrate deviations from Thurstonian model predictions of method power revealing the need to experiment with several methods using commercial-type products commonly tested within a business or research setting prior to selecting an optimal method to use.

Serving Duplicates in a Single Session Can Selectively Improve Sensitivity of Duplicated Intensity Ranking Tests

Duplicating ranking tests can improve the power of preference and sensory intensity tests, and reduce the number of panelists required. With multiple-samples rankings, duplications could be served using different protocols: in two serving sessions (two sample sets, that is, 2SS) to allow a break period or jointly in one serving session (one sample set, that is, 1SS). Evaluating the duplicates in a single session improves statistical data analysis but increases concerns of sensory fatigue, adaptation, memory, and possible irritation. The extent to which each serving protocol for duplicated ranking affects detection of differences has not been reported. This study used panelists (n = 75) who performed both ranking test protocols on two sets of orange juice samples (k = 3). One set was designed to obtain higher similarity than the other set to investigate the effects of degree of difference. Sweetness and yellow color intensity rankings were performed separately for each set to compare the protocols between attributes. The magnitude of the differences was evaluated using Mack-Skillings (M-S) statistics, and the total and individual rank sum differences at varied n (10 to 75) values. With similar set samples, the 2SS serving protocol improved differentiation for yellow color intensity. Although in sweetness, using the 1SS serving protocol showed higher M-S statistics and higher sum of total rank sum differences. Paired comparisons followed the same pattern. With very different samples, both protocols had comparable performance. This study showed that serving duplicates in the 1SS can improve duplicated ranking's power, depending on the task difficulty and attribute, and should be considered before splitting replications into two sessions.

PRACTICAL APPLICATION

This study evaluated two alternative and not previously studied protocols for conducting a duplicated ranking test. One protocol required that each panelist received duplicates in the same single serving session (1SS), against the alternative of serving duplicates separately in two sessions to allow a break period (2SS). Two attributes: yellow color intensity and sweetness intensity of orange juice samples were studied. This study showed that serving duplicates in the same single session can improve duplicated ranking's power, depending on the task difficulty and attribute, and should be considered before splitting replications into two sessions.

Objective and perceptual evaluation of distance-dependent scattered sound effects in a small variable-acoustics hall

Performance spaces are characterized by a complex sound field, due to the presence of absorptive and diffusive surfaces. In situ evaluations of the acoustic effects that these surfaces have on the objective acoustic parameters and on sound perception have not yet been fully understood. To this aim, acoustic measurements have been performed in a variable-acoustic concert hall, the Espace de Projection, at the Institut de Recherche et Coordination Acoustique/Musique. These measurements have allowed the effects of one single wall to be determined. A diffusive and a reflective condition of one of the long lateral walls of the shoebox-like hall have been considered, while the other surfaces have been fixed in absorptive mode. Measurements have been carried out at different distances from the test wall, using an artificial head and an array of omnidirectional microphones. Objective acoustic parameters, such as early decay time, reverberation time (T₃₀), clarity (C₈₀), definition (D₅₀), and interaural cross correlation, have been compared between both conditions. In addition to the objective indexes, a perceptual evaluation has been performed using listening tests that had the purpose of determining the maximum distance from a diffusive surface at which acoustic scattering effects are still audible.

A transfer of technology from engineering: use of ROC curves from signal detection theory to investigate information processing in the brain during sensory difference testing

This article reviews a beneficial effect of technology transfer from Electrical Engineering to Food Sensory Science. Specifically, it reviews the recent adoption in Food Sensory Science of the receiver operating characteristic (ROC) curve, a tool that is incorporated in the theory of signal detection. Its use allows the information processing that takes place in the brain during sensory difference testing to be studied and understood. The review deals with how Signal Detection Theory, also called Thurstonian modeling, led to the adoption of a more sophisticated way of analyzing the data from sensory difference tests, by introducing the signal-to-noise ratio, d', as a fundamental measure of perceived small sensory differences. Generally, the method of computation of d' is a simple matter for some of the better known difference tests like the triangle, duo-trio and 2-AFC. However, there are occasions when these tests are not appropriate and other tests like the same-different and the A Not-A test are more suitable. Yet, for these, it is necessary to understand how the brain processes information during the test before d' can be computed. It is for this task that the ROC curve has a particular use.

Fine grain temporal analysis in aphasia: Evidence from auditory gap detection

Auditory temporal processing was investigated in individuals with acquired aphasia using a task in which they were asked to detect brief silent gaps inserted between noise segments modeled after formants in speech. To examine within-channel gap detection, gaps of 10, 20, 40, and 80ms duration were inserted between an initial segment (IS) and a trailing segment (TS) centered at the same frequency (1kHz). In a between-channel gap detection condition, gaps of 20, 40, 80, and 100ms duration were inserted between an IS that differed in frequency (4kHz) from the TS (1kHz). The effect of gap onset timing was examined in both conditions by systematically varying the duration of the IS by 10, 20, or 40ms. A combined analysis revealed that for both conditions and all gap and IS durations, individuals with aphasia produced fewer correct responses than age-matched neurologically intact controls. Separate condition analyses revealed that when noise segments were centered at the same frequency, individuals with aphasia demonstrated poorer accuracy in detecting 40 and 80ms gaps relative to normal controls (p<0.001). When gaps were inserted between noise segments differing in frequency, on average, aphasic subjects performed less accurately at durations of 40, 80 and 100ms (p<0.025). Detection in both groups decreased with smaller IS durations. The difficulties with gap detection observed in the aphasic group suggest the existence of fundamental problems in processing the temporal form or microstructure of sounds characterized by rapidly changing onset dynamics.