Duo-trio Test Research Articles

Utilization of Shrimp Waste as a Raw Material in Shrimp Sauce and Its Application on Shrimp Sauce Tilapia Dishes

One of the innovations to increase the economic value of shrimp waste is the implementation of shrimp waste into shrimp sauce and its use in shrimp sauce tilapia dishes. The purpose of this study was to determine the protein and lead (Pb) content of shrimp waste and shrimp sauce, the degree to which shrimp sauce differed in aroma, taste, and color from commercial oyster sauce, and the degree to which panelists preferred shrimp sauce tilapia dishes via organoleptic tests. This was a two-repetition experimental study with a completely randomized design (CRD). The protein content was determined using the Kjeldahl semi-micro method, whereas the lead content was determined using the spectrophotometric method. The Duo-Trio Test was used to determine the difference in organoleptic properties between shrimp sauce and commercial oyster sauce, whereas ANOVA followed by DMRT was used to analyze the hedonic properties of shrimp sauce tilapia dishes. The results of this study indicate that shrimp waste contains 18.281 percent protein and shrimp sauce contains 6.107 percent protein. The content of lead (Pb) in shrimp waste was 0.750 mg/kg, while the content of lead (Pb) in shrimp sauce was 0.052 mg/kg. The organoleptic tests revealed that shrimp sauce had a distinct aroma, taste, and color from commercial oyster sauce, whereas the hedonic tests revealed no difference in the hedonic properties of the three dishes' aromas, but there were differences in the hedonic properties of their taste and properties. The three dishes exhibit hedonic color. Panelists preferred commercial oyster sauce tilapia dishes over shrimp sauce tilapia dishes and commercial oyster sauce mixed tilapia dishes in terms of aroma, taste, and color (1:1). The shrimp sauce formula should be refined further so that it more closely resembles commercial oyster sauce in terms of aroma, flavor, and color.

Effectiveness of Oat-Hull-Based Ingredient as Fat Replacer to Produce Low Fat Burger with High Beta-Glucans Content.

Low-fat beef burgers with high beta-glucan content was obtained using a gel made from an oat-hull-based ingredient as fat replacer. Two levels of fat substitution were considered: 50% (T1) and 100% (T2). The nutritional composition, cooking yield, textural properties, color characteristics and consumer preference were evaluated, in comparison with a burger without fat replacer (CTRL). After cooking, T2 burger showed a significant increase in the cooking yield and a very low lipid content (3.48 g 100 g−1) as well as a level of beta-glucans per single portion (2.96 g 100 g−1) near the recommended daily intake. In T1 burger, the decrease of lipid content was mitigated during the cooking process, because the beta-glucans added had a fat-retaining effect. Compared to CTRL, replacing fat led to a softer texture of cooked burgers evaluated by Texture Profile Analysis. The differences in color, significant in raw burgers, were smoothed with cooking. The consumer evaluation, carried out according to the duo-trio test, highlighted significant differences between CTRL and T2 burgers in terms of odor, taste, color and texture. The consumers expressed a higher preference for the T2 burger, probably due to its softer texture and greater juiciness.

Spatial movement pattern recognition in soccer based on relative player movements.

Knowledge of spatial movement patterns in soccer occurring on a regular basis can give a soccer coach, analyst or reporter insights in the playing style or tactics of a group of players or team. Furthermore, it can support a coach to better prepare for a soccer match by analysing (trained) movement patterns of both his own as well as opponent players. We explore the use of the Qualitative Trajectory Calculus (QTC), a spatiotemporal qualitative calculus describing the relative movement between objects, for spatial movement pattern recognition of players movements in soccer. The proposed method allows for the recognition of spatial movement patterns that occur on different parts of the field and/or at different spatial scales. Furthermore, the Levenshtein distance metric supports the recognition of similar movements that occur at different speeds and enables the comparison of movements that have different temporal lengths. We first present the basics of the calculus, and subsequently illustrate its applicability with a real soccer case. To that end, we present a situation where a user chooses the movements of two players during 20 seconds of a real soccer match of a 2016–2017 professional soccer competition as a reference fragment. Following a pattern matching procedure, we describe all other fragments with QTC and calculate their distance with the QTC representation of the reference fragment. The top-k most similar fragments of the same match are presented and validated by means of a duo-trio test. The analyses show the potential of QTC for spatial movement pattern recognition in soccer.

Kualitas Organoleptik dan Isotermis Sorpsi Air (ISA) Ikan Cakalang (Katsuwonus pelamis L.) Presto Asap Cair

Skipjack tuna is widely consumed by the people in North Sulawesi in many forms. One famous product is Cakalang Fufu or Smoked Skipjack. Conventional smoked skipjack fish processing has many shortcomings i.e. longer processing time and the presence of tar residues and aromatic polycyclic hydrocarbon compounds (benzo(a)pyrene) which are harmful to human health. The use of liquid smoke is safer since the concentration of liquid smoke can be controlled. Additionally, it is equipped with a cooking method to produce fish with soft fins and bones so that it can be directly consumed. The purpose of this study was to obtain the best formula in the process of making liquid smoked skipjack. Two concentrations of liquid smoke 0.8% and 1.2, three various cooking time using pressure cooker presto (60, 90 and 120 minutes), and two ways of administering liquid smoke were used as treatments. Sensory hedonic test, duo-trio test, MSI test, moisture content, pH and phenol value were measured in this study.The results showed that the best formula in this study was to soaked skipjack tuna in 1.2% liquid smoke, cooked with pressure cooker for 90 minutes and then heated at a temperature of 150°C for 30 minutes. The Duo Trio Test results showed that skipjack tuna in 0,8% and 1.2% liquid smoke concentration either by soaked the fish in advance and cooked by pressure cooker, or cooked by pressure cooker in liquid smoke were tastier than conventional smoked fish samples.Moisture Sorption Isotherm (MSI) test results show that all skipjack tuna with liquid smoke, at RH> 60% will begin to absorb the water, so packaging is needed in this part. The MSI Oswin curve model accurately describes the actual curve with an MRD value of 7.51

Confirmation of odd sample bias in triadic design preference tests with a no-preference option, using confusable stimuli, and a solution

Two preference test methods utilizing triadic designs (i.e., presenting two identical products and a different product in a test) have been proposed to improve the validity of the paired preference test using a no-preference response option, by considering responses generated from preference bias (i.e., consumers’ responses are tilted toward a preference response rather than a no-preference response, resulting in the overestimation of preference responses). One of the test methods was the replicated duo-trio difference-preference (DT-Preference) test method, which had a balanced-reference design, while the other was the triadic preference test method. These two methods were designed to provide more conservative preference results in different ways. For the DT-Preference test method, it was assumed that the preference responses that were simply generated from the preference bias would also be prone to an odd sample bias (i.e., consumers tilted the preference against the stimulus that was most different from the other two) in the triadic design. For the triadic preference test method, the responses were screened out if the subjects reported a preference between the identical stimuli, assuming no bias in the triadic design. In the present study, the odd sample bias assumed in the triadic design was tested by the triadic preference test method and the DT-Preference test method by using two pairs of confusable orange juice stimuli assumed to have negligible preference by 256 consumers. For the DT-Preference test method, two variants of the duo-trio test designs were used. The odd sample bias was confirmed for all test methods using triadic designs, invalidating the application of the triadic preference test method without replication.

Alternatif Fortification Vitamin A for Lactating Mother Using Siomay Sauce Enriched with Red Palm Oil

Siomay is a popular street foods in urban and rural areas of Indonesia. Due to its characteristics siomay sauce can be incorporated with RPO (RPO) for vitamin A fortification. The objective of the study were determining the effect of RPO addition to the characteristic of siomay sauce, and determining the preference of siomay sauce added with various amount of RPO. A four levels addition of RPO (0.0 g, 1.5 g, 3.0 g and 4.5 g) were added to siumay sauce. The physical characteristics (viscosity, emulsion stability), sensory evaluation (hedonic test and duo-trio test) of the sauce, and the retinol equivalent of fortified siomay sauce were evaluated. The result showed that viscosity of siomay sauce increased with increasing addition of RPO into the sauce. The hedonic test revealed that the overall preference of original siomay sauce added with 4.5 g of RPO was not significantly diferent from the controll. In addition, siomay sauce enriched with 4,5 g RPO could increase 325.22 ?g retinol equivalents (RE) or equal to 38.26 % of the RDA of vitamin A for lactating woman. The finding suggest that siomay sauce fortified with RPO could be used for combating Vitamin A deviciency.

Effects of sulfate and nitrate on the taste of water: a study with a trained panel

The role of sulfate and nitrate in the taste of drinking water is not entirely clear. Taste threshold concentrations (TTCs) were estimated for these two species by the 3-AFC method by a trained panel, as sodium and calcium salts. In both cases TTCs for nitrate were about 100 mg NO 3 /L, twice the usual reference value of international recommendations. TTCs for sulfate were about 160 mg SO 4 /L (sodium salt) and 80 mg SO 4 /L (calcium); 75% detection values were also estimated for both anions. An experiment with a series of duo-trio tests plus preference showed that sulfate at low concentrations tended to improve the taste of water. However, at high concentrations it was perceived negatively: salty and bitter were the main descriptors used. The reversion concentration took place between 176 and 259 mg SO 4 /L. These results indicate that nitrate has to be considered an important issue for health, but with no relevant role in the taste of water. Sulfate shows a positive influence at moderate concentrations but becomes negative at high levels. The usual aesthetic-based level of 250 mg/L established by international regulations appears to be reasonable. The findings of this study with trained panellists are preliminary. Future research with consumer panels is recommended.

Influence of hop harvest date of the ‘Mandarina Bavaria’ hop variety on the sensory evaluation of dry‐hopped top‐fermented beer

To impart a special hop aroma to beer, dry-hopping is a technique that is becoming more and more popular with commercial breweries. Nevertheless, until now little was known about the factors that influence the reproducibility (and consistent product quality) of dry-hopping with flavour varieties. One factor that could influence the sensory impressions and aroma profile compositions of dry-hopped beers is the hop harvest date. Therefore, to determine the effects of different harvest dates of the flavour variety ‘Mandarina Bavaria’ on the aroma of top-fermented beer, laboratory-scale dry-hopping trials were performed. Besides tasting sessions of brewed beers, relative quantities of selected hop-derived, as well as beer-originated aroma compounds, were investigated by headspace–solid-phase microextraction–gas chromatography–mass spectrometry. Duo–trio tests between the beers hopped with pellets of different harvest dates showed no significant differences (α = 0.05) between them. In addition, these beers had similar profiles in a five-point profile tasting scheme. On the other hand, relative concentrations of some hop-derived aroma compounds – especially myrcene, which is known to be able to contribute to beer flavour – increased corresponding to a later harvest date, while beer originated volatiles were not different between the beers. Analytical results combined with the results of sensory evaluations led to the conclusion that the harvest date of Mandarina Bavaria was not a dominant factor in the dry-hopping aroma of top-fermented beers. High amounts of fermentation by-products are likely responsible for masking effects resulting in no sensory distinctness between the samples with different hop aroma compound concentrations. Copyright © 2016 The Institute of Brewing & Distilling

Idiographic duo–trio tests using a constant-reference based on preference of each consumer: Sample presentation sequence in difference test can be customized for individual consumers to reduce error

As reformulations and processing changes are increasingly needed in the food industry to produce healthier, more sustainable, and cost effective products while maintaining superior quality, reliable measurements of consumers' sensory perception and discrimination are becoming more critical. Consumer discrimination methods using a preferred-reference duo–trio test design have been shown to be effective in improving the discrimination performance by customizing sample presentation sequences. However, this design can add complexity to the discrimination task for some consumers, resulting in more errors in sensory discrimination. The objective of the present study was to investigate the effects of different types of test instructions using the preference-reference duo–trio test design where a paired-preference test is followed by 6 repeated preferred-reference duo–trio tests, in comparison to the analytical method using the balanced-reference duo–trio. Analyses of d' estimates (product-related measure) and probabilistic sensory discriminators in momentary numbers of subjects showing statistical significance (subject-related measure) revealed that only preferred-reference duo–trio test using affective reference-framing, either by providing no information about the reference or information on a previously preferred sample, improved the sensory discrimination more than the analytical method. No decrease in discrimination performance was observed with any type of instruction, confirming that consumers could handle the test methods. These results suggest that when repeated tests are feasible, using the affective discrimination method would be operationally more efficient as well as ecologically more reliable for measuring consumers' sensory discrimination ability.

Comparison of the Sensory Ability of Experts and Untrained Panelists to Evaluate Cooked Rince by using Five Sensory Methods

This experiment aimed to compare the sensory ability of experts and untrained to evaluate three rice varieties by using five sensory evaluation methods. All panelists showed significant differences in their sensory abilities to distinguish among Haiami, Chucheong, and Dasan 1 rice varieties when using the duo-trio test and triangle test. The expert panelists showed a clear preference in the following order: Haiami > Chucheong > Dasan 1, when using the paired comparison test, ranking test, and multiple comparison test. However, the untrained panelists showed no significant differences in their sensory ability to distinguish between the Haiami and Chucheong varieties when using the multiple comparison test. The results indicate that, for sensory evaluation of cooked rice by untrained panelists, the paired comparison test is suitable for evaluating two samples and the ranking test is suitable for evaluating more than two samples.

The performance of the dual reference duo-trio (DRDT) method using a balanced-reference mode

The balanced-reference duo-trio test using the comparison of distances (COD) strategy is a widely used unspecified discrimination method. However, it suffers lower testing power. A dual reference duo-trio (DRDT) method was proposed recently as an improved duo-trio in the sensory literature. This paper proposes a new cognitive decision strategy for the DRDT, involving the comparison of pairs of distances (COPD) and investigates theoretically the performance of the DRDT based on a simulation-derived psychometric function. The DRDT is compared with the conventional balanced-reference duo-trio (DT) and the triangle methods. Comparison results show that the DRDT assuming the COPD is more sensitive than the conventional DT assuming the COD, and is more powerful than the conventional DT and the triangle methods for both difference testing and similarity/equivalence testing. The averaged generalized power efficiency of the DRDT is about 34% over that of the conventional DT, and is about 13% over that of the triangle method.

Unspecified duo–trio tests can be as powerful as the specified 2-AFC: Effects of instructions and familiarization procedures on cognitive decision strategies

Using signal detection theory (SDT) and Thurstonian analysis, it has been possible in the food industry to make various business decisions such as reformulations and cost reductions based on the degree of consumer sensory discriminability by applying equivalence/difference testing. To achieve more efficient decision-making, it is important to investigate a theoretically and operationally more powerful consumer discrimination test method. Cognitive decision strategies used in discrimination methods largely determine relative test power and thus are of theoretical and practical significance. The goal of this study was to investigate if test procedures using a constant-ref. duo–trio design enable untrained/naïve subjects to use a powerful 2-AFC strategy. Although previously the constant-ref. duo–trio design showed operational superiority to other unspecified test methods, the ‘comparison of distance’ (COD) strategy which is conventionally assumed for the duo–trio, lacks theorized power. The tested variables included two versions of duo–trio design, different familiarizations, instructions and experimental session designs. Three different iced tea samples were discriminated from a reference by 263 untrained/naïve subjects using 5 different duo–trio test procedures. Results showed that untrained/naïve subjects were able to perform the duo–trio with the reference presented twice, first and middle (DTFM) as a 2-AFC procedure, even with multiple pairs in a block design, after only two reference tastings with the information of the constant-reference. The duo–trio preceded by specified tetrad tests also showed potential as another efficient two-sequence test design. These results suggest that such constant-ref. duo–trio protocols using a 2-AFC strategy can be an alternative to the unspecified triangle and tetrad test.

Tracking the variation of small-batch micro-oxygenated wines using phenolic, anthocyanin and colorimetric determinations

This research tracked the variation in micro-oxygenated (MOX) Merlot wines exposed to 0, 5, 10, 20 and 60 mL O2/L/month for 40 days, using compositional [total phenolics, flavanols, tartaric esters, flavonols, condensed tannins, anthocyanins (total, ionized), degree of ionization of anthocyanins, chemical age (i, ii)] and colorimetric [color density, color intensity, color hue, % yellow, % red, % blue, L*, a*, b*, chroma, hue angle and saturation] determinations. Two-factor analyses of variance, principal component analysis (PCA) and relative standard deviations (rSTDs) were used to evaluate MOX and tank variation. PCA also summarized the interrelationships among the determinations. Lower tank-to-tank variation was observed for higher MOX rates. The lowest rSTDs were observed for total phenolic and hue angle suggesting these variables were most sensitive for tracking MOX and tank effects, respectively. Duo-trio sensory tests discerned aroma, flavor-by-mouth and visual differences at the higher MOX treatments. The high number of significant inter-correlations among the many compositional/colorimetric determinations suggested that a subset of analyses could be used for the routine tracking of MOX treatments. With the high variability associated with delivery of low MOX rates in small tanks, it is recommended that winemakers monitor all tanks on an individual basis to ensure adequate quality control.

Sensory discrimination by consumers of multiple stimuli from a reference: Stimulus configuration in A-Not AR and constant-ref. duo-trio superior to triangle and unspecified tetrad?

In the food industry, overall discrimination tests are used with untrained/naïve consumer subjects to compare multiple test stimuli against a fixed reference, such as a company’s gold standard or a stimulus familiar to the consumer. Such tests are used for various objectives, including reformulation and cost reduction. Yet, studies on relative discrimination power and efficiency have been limited to experimental designs with a fixed pair of stimuli and method comparisons based on the same numbers of tests. In the present study, two reminder methods, A-Not A with Reminder (A-Not AR) and 2-AFC with Reminder (2-AFCR), were investigated as potentially better methods for experimental designs including comparisons of multiple pairs of stimuli for consumer discrimination. 2-AFCR is procedurally equivalent to a constant-reference duo-trio test with the reference presented first (DTF) and thus this test is referred to as the constant-ref. DTF/2-AFCR test in this paper. The practical efficiency of these two reminder methods, attributed to their effective stimulus configurations in replicated tests (i.e. using a fixed reference and lower number of different stimuli required in a test), was tested in comparison with the two most commonly used balanced reference classification methods, the triangle test and the unspecified tetrad test, by equalizing the number of stimuli required for the different methods. Namely the relative operational discrimination power was studied based on the same number of stimuli rather than the same number of tests. 180 naïve consumers performed a set of 12 replicated triangle tests and, based on the results, were divided into one of three equally-performing groups. A related-samples design was implemented for comparison between the triangle and the other three methods. An independent-samples design was implemented across the three groups to compare the A-Not AR, constant-ref. DTF/2-AFCR, and unspecified tetrad methods. Statistical ratio comparisons of d′ estimates obtained from different methods revealed that discrimination performance in the reminder methods was better than in both the tetrad and triangle methods. No discrimination difference was found between the triangle and tetrad tests having all possible test sequences, although the triangle test considering only the optimal test sequences, which were the same as those in the constant-ref. DTF/2-AFCR, resulted in superior discrimination than the tetrad test. Collectively, these results suggest that when assessing the discriminability of multiple stimuli from a fixed reference, the reminder scheme is the superior research design.

Optimal difference test sequence and power for discriminating soups of varying sodium content: DTFM version of dual-reference duo–trio with unspecified tetrad tests

As sodium reduction has become very important in the food industry, various types of unspecified duo–trio tests have been studied to improve its efficiency for studying samples with high sodium content, and a constant-saltier-reference duo–trio test with dual reference, one reference in the first position and the second reference in the middle between the two test stimuli (DTFM), has been recommended. For the duo–trio test, a ‘comparison of distance’ (COD) strategy has been generally assumed. Yet, theoretically for DTFM, the 2-AFC reminder (2-AFCR) τ-strategy is also possible, which would make DTFM more efficient than the unspecified tetrad test. In this study, the hypothesis was that when subjects are pre-exposed to two types of samples, the 2-AFCR τ-strategy can be adopted in a constant-reference DTFM using a fixed design experiment. In order to test this hypothesis, unspecified tetrad tests involving categorization tasks were used as a means of pre-exposure to the two types of samples for DTFM, and a performance comparison was conducted. Two groups of 39 untrained/naive subjects performed both the unspecified tetrad and DTFM tests in varying orders for the purpose of discriminating two different soup samples of varying sodium content. A comparison of the d′ estimate across different methods supported the hypothesis that the more efficient 2-AFCR τ-strategy was appropriate when the tetrad test preceded DTFM, while when DTFM was performed first without pre-categorization of samples, the conventional duo–trio COD strategy was appropriate for the constant-reference DTFM.

Affective discrimination methodology: Determination and use of a consumer-relevant sensory difference for food quality maintenance

To achieve more efficient decision making for many business objectives including reformulations and processing changes in the food industry, the important questions become 1) what is the best way to measure consumer discrimination and 2) how much discrimination is meaningful in consumer preference that can be used as a business action standard for food quality maintenance. The purpose of the present paper was to develop a consumer sensory discrimination methodology using affective reference framing to provide more accurate information on both questions. For such affective methods, two versions of repeated duo–trio tests using the preferred sample as reference were implemented: Affective group I—each of 8 repeated duo–trio tests was preceded by a paired-preference test; and Affective group II—a paired-preference test was performed before each of the two sub-sessions consisted of 6 repeated duo–trio tests and the preferred sample was used as a constant-reference during the sub-session. The discrimination performance of these tests was compared to the analytical balanced-reference duo–trio test. Results indicated that for affective group I only, it was possible to identify the ‘affective discriminators’ who showed genuine preference for one product over another and their sensory discrimination in the affective method was significantly higher than in the analytical method. It suggested that this affective method is a desirable consumer sensory methodology that can reveal insightful consumer-relevant sensory differences by comparing sensory discriminations between the so-called ‘affective discriminators’ and ‘affective non-discriminators’.

Tetrads, triads and pairs: Experiments in self-specification

Sensory difference tests can be used to investigate how well consumers can discriminate between very similar, confusable products. For this reason, it is desirable that the products are tested in a manner as similar as possible to realistic conditions of consumption. For some of these tests, it is desirable that the experimenter does not specify the nature of the difference; the consumers have to discover this for themselves. The methods generally used for this class of tests are the triangle and duo–trio. Recently, the (unspecified) tetrad method has emerged as a candidate to replace the triangle and duo–trio tests, because it is more powerful, although not as powerful as the 2-AFC and 3-AFC. Using a model and a beverage system, it was confirmed that the tetrad method was more powerful than the triangle method, despite the fact that the greater memory load of the tetrad reduced its d′ values. To initiate an investigation into more powerful tests, several self-specification protocols were developed, which differed from those used in prior investigations. These protocols successfully converted triangle tests into self-specified 3-AFCs, with a consequent increase in power. Triangle, tetrad, self-specified 2-AFC and 3-AFC methods were then compared, with the tetrad being more powerful than the triangle and the self-specified 2-AFC and 3-AFC methods being more powerful than the tetrad.

Superior performance of constant-saltier-reference DTF and DTFM to same-different tests by consumers for discriminating products varying sodium contents

Reducing sodium content in foods and beverages has become very important, and great efforts are being made to achieve this while maintaining overall taste/acceptance of food. This requires more robust sensory discrimination test methods in terms of operational power because discrimination tests using food/beverages with high sodium contents might be more prone to adaptation and memory bias which might reduce the operational power of the test methods. The operational test power of six versions of the duo-trio test method (two different versions of replicated tests under three reference modes – constantly stronger-reference (SR) vs. balanced-reference vs. constantly weaker-reference (WR)) were investigated using a pair of tomato juices with different sodium content in comparison to the same-different tests using a balanced-design. The two duo-trio versions were the traditional duo-trio with a reference presented first (DTF) and the duo-trio with the reference presented both at the first and in the middle between the two alternative test samples (DTFM). An examination of the d′ estimates indicated that discrimination significantly improved across all duo-trio tests and the same-different tests when using naïve consumer subjects and when the sample in the first position in a test was a stronger (saltier) sample. This observation granted operational superiority to the DTF and DTFM in comparison to the same-different test, using the stronger (saltier) product as a constant-reference for discriminating products with high sodium content.

A Statistical Agreement-Based Approach for Difference Testing

A statistical approach based on measures of agreement is proposed for use in a sensory analysis context. This approach considers the idea of using statistical agreement to provide information on the homogeneity of the raters' responses, so that this information can then be used to discriminate between products. It can also be used to measure the expertise level of raters. Although the prime focus is on difference testing by the triangle test (ISO 4120:2008), the proposed methodology can also be applied in other contexts such as the paired comparison test (ISO 5495:2009) or the duo-trio test (ISO 10399:2010), among others. The proposed approach is not a substitute for binomial statistical analysis, but rather it can be used as a complement. It is especially useful when few panelists are available and replications are needed. An experiment that evaluates two types of Iberian dry-cured pork loins through the triangle test is performed to illustrate the applicability of the proposed approach. Practical Applications The proposed methodology is very helpful for users of sensory analysis techniques, and especially for those focused on differentiation tests. It can complement the classical methodologies on this topic. It is especially useful when there are few raters and replications must be performed. It can also be applied to evaluate the accuracy of panelists being trained by an expert.

Higher performance of constant-reference duo–trio test incorporating affective reference framing in comparison with triangle test

For measuring the sensory discriminability of consumers, ways to optimize the test protocols were investigated in relation to the concept of the test practicality and operational power. Specifically, reference frames using consumers’ affective state of mind and adoption of selective tasting orders of products in a test were designed as the operationally more powerful ways of using consumer discrimination tests. Their effects were investigated in terms of three different versions of the constant-reference duo–trio tests, in comparison to the balanced-reference triangle test as a control protocol. The three different duo–trio protocols were: (1) a duo–trio with a constant-reference of a stronger sample; (2) a duo–trio with a constant-reference of a stronger sample with a fake brand name provided and (3) a duo–trio with a constant-reference of each subject’s preferred sample. Based on signal detection analysis assuming a comparison of distances strategy, all three duo–trio tests were determined to be superior to the triangle test when the first two replications were compared, while only the duo–trio test using the affective reference frame (either with the brand name encoded or with the preferred reference), were found to be superior to the triangle test when all replications were compared. Significant sequence effects were found only for the triangle test. These results indicated that the duo–trio with a constant-reference incorporating the consumers’ state of mind by using the affective reference frames and selective test sequences had the operationally favorable sample sequences and higher test practicality.